doc/devel/weekly.html - go - Git at Google

 <!-- Weekly Snapshot History -->

 <p>This page summarizes the changes between tagged weekly snapshots of Go.
 For full details, see the <a href="http://code.google.com/p/go/source/list">Mercurial change log</a>.</p>

 <p>Weekly snapshots occur often and may not be stable.
 If stability of API and code is more important than having the
 latest features, use the <a href="release.html">official releases</a> instead.</p>

 <p>To update to a specific snapshot, use:</p>

 <pre>
 hg pull
 hg update weekly.<i>YYYY-MM-DD</i>
 </pre>

 <h2 id="2011-12-22">2011-12-22</h2>

 <pre>
 This snapshot includes changes to the images/ycbcr and testing packages, and
 changes to the build system.

 The types for managing Y'CbCr images in the image/ycbcr have been moved to the
 image and image/color packages. A gofix module will rewrite affected code.

 The testing package's B type (used when running benchmarks) now has the same
 methods as T (used in tests), such as Print, Error, and Fatal.

 This weekly adds a new command named 'go' for building and testing go programs.
 For Go 1, the go command will replace the makefile-based approach that we have
 been using. It is not yet ready for general use, but all.bash does use it to
 build the tree. If you have problems building the weekly, you can 'export
 USE_GO_TOOL=false' before running all.bash to fall back to the makefiles.

 Other changes:
 * archive/zip: add SetModTime method to FileHeader.
 * build: make use of env (thanks Mikio Hara),
 	fixes to make "go install" work on windows (thanks Alex Brainman).
 * bytes: add two Buffer examples.
 * cgo: support export for built-in types (thanks Maxim Pimenov).
 * cmd/go: avoid infinite loop with package specific flags (thanks Mikio Hara),
 	fixes to build standard library,
 	implement test command,
 	make sure use of pthread for gcc-4.5 and beyond (thanks Mikio Hara),
 	respect $GCFLAGS,
 	use spaces consistently in help message (thanks Roger Peppe),
 	many other improvements.
 * codereview: initialize "found" in codereview.py (thanks Miki Tebeka).
 * crypto/mime/net/time: add netbsd to +build tags (thanks Joel Sing).
 * crypto/tls: don't assume an RSA private key in the API.
 * crypto/x509: don't crash with nil receiver in accessor method.
 * doc/effective_go: discuss redeclaration.
 * doc: delete go course notes,
 	refer to http://build.golang.org/ where applicable (thanks Robert Hencke),
 	suggest code.google.com/p/go instead of go.googlecode.com/hg.
 * encoding/binary: add Write and Read examples,
 	add more benchmarks (thanks Roger Peppe).
 * encoding/gob: arrays are zero only if their elements are zero.
 * encoding/json: cleanup leftover variables in array decoding (thanks Rémy Oudompheng),
 	examples for Marshal and Unmarshal.
 * exp/ssh: rename ClientAuthPublicKey helper ClientAuthKeyring (thanks Dave Cheney),
 	simplify Stdin/out/errPipe methods (thanks Dave Cheney).
 * fmt: speed up floating point print, clean up some code,
 	make the malloc test check its counts.
 * gc: allow use of unsafe.Pointer in generated code,
 	avoid unsafe in defn of package runtime,
 	better linenumbers for inlined functions,
 	better loopdepth analysis for labels,
 	implement and test \r in raw strings,
 	inlining, allow empty bodies, fix _ arguments,
 	omit argument names from function types in error messages.
 * go/ast, parser: remember short variable decls. w/ correspoding ident objects.
 * go/build: add new +build tags 'cgo' and 'nocgo'.
 * go/doc, godoc: move export filtering into go/doc
 * go/printer, gofmt: fine tuning of line spacing.
 * go/scanner: strip CRs from raw literals.
 * gob: isZero for struct values.
 * godoc: allow examples for methods (thanks Volker Dobler),
 	show methods of anonymous fields.
 * goinstall: only suggest -fix for bad imports when appropriate.
 * govet: add checking for printf verbs,
 	divide the program into one file per vetting suite.
 * html: more parser improvements (thanks Andrew Balholm).
 * json: some tests to demonstrate bad error messages,
 	use strconv.Append variants to avoid allocations in encoding.
 * ld: add support for netbsd signature note section (thanks Joel Sing),
 	allow for IMAGE_REL_AMD64_ADDR32NB relocation type (thanks Alex Brainman).
 * math/big: Rand shouldn't hang if argument is also receiver.
 * misc/builder: set default builder host to build.golang.org.
 * misc/dashboard: delete old build dashboard code ,
 	improvements and fixes for the go implementation.
 * misc/vim: fix go filetype detection (thanks Paul Sbarra).
 * net, syscall, os: set CLOEXEC flag on epoll/kqueue descriptor.
 * net, syscall: interface address and mask (thanks Mikio Hara).
 * net/http: added interface for a cookie jar (thanks Volker Dobler),
 	test fixes (thanks Alex Brainman).
 * net: add DialTimeout,
 	sort Makefile entries (thanks Mikio Hara).
 * os, syscall: beginnings of NetBSD support (thanks Christopher Nielsen).
 * os/exec: add test to verify net package's epoll fd doesn't go to child,
 	disable the ExtraFiles test on darwin.
 * os: don't trust O_CLOEXEC on OS X,
 	make sure Remove returns correct error on windows (thanks Alex Brainman).
 * path, path/filepath: add Dir to complement Base.
 * path/filepath.Rel: document that the returned path is always relative.
 * runtime: don't panic on SIGILL, just crash.
 * spec: be precise about newlines.
 * sql: add Rows.Columns.
 * strconv: fix bug in extended-float based conversion,
 	implement faster parsing of decimal numbers, and
 	reduce buffer size for multi-precision decimals (thanks Rémy Oudompheng).
 * syscall: regenerate z-files for linux/arm (thanks Mikio Hara),
 	sort Makefile, mkall.sh and mkerrors.sh entries (thanks Mikio Hara).
 * test/bench/go1: first draft of Go 1 benchmark suite.
 * testing: compare Log to Println (thanks Robert Hencke),
 	make signalling safer for parallel tests.
 * text/template: better error message for empty templates,
 	fix handing of nil arguments to functions (thanks Gustavo Niemeyer).
 * time: add JSON marshaler for Time (thanks Robert Hencke),
 	new AddDate method (thanks Roger Peppe).
 * various: use $GCFLAGS and $GCIMPORTS like Make does (thanks Maxim Pimenov).
 </pre>

 <h2 id="2011-12-14">2011-12-14</h2>

 <pre>
 This snapshot includes language changes and changes to goinstall and gofmt.

 Equality and inequality (== and !=) are now defined for struct and array
 values, respectively, provided the elements of the data structures can
 themselves be compared. See the Go 1 release notes for the details:
 	http://weekly.golang.org/doc/go1.html#equality

 The rune type is now an alias for int32 and character literals have the default
 type of rune. Code that uses int where it should use rune will break.
 See the Go 1 release notes for the details:
 	http://weekly.golang.org/doc/go1.html#rune

 Goinstall now expects Google Code import paths to be of the form:
 	"code.google.com/p/go-tour/tree"
 It will reject imports in the old style "go-tour.googlecode.com/hg/tree".
 There is a gofix module to rename such imports.
 Use goinstall -fix to update broken packages.

 Gofmt's flags have been modified slightly.
 The -tabintent flag has been renamed -tabs.
 The -spaces flag has been removed.

 Other changes:
 * 5c, 6c, 8c: support 64-bit switch value (thanks Anthony Martin).
 * 8c: handle 64-bit switch value.
 * archive/tar: use struct comparison not DeepEqual (thanks Christopher Wedgwood).
 * archive/zip: make zip understand os.FileMode (thanks Roger Peppe).
 * bufio: make the minimum read buffer size 16 bytes.
 * build: disable cgo on Windows/amd64,
 	regularize packages so they may be built without Makefiles.
 * bytes: faster Count, Index, Equal.
 * cgo: add basic gccgo support (thanks Rémy Oudompheng).
 * codereview: fix path slash issue (thanks Yasuhiro Matsumoto).
 * compress/flate: fix out of bounds error.
 * contribute.html: do not fill in the reviewer field (thanks Florian Weimer).
 * crypto/aes: made faster by eliminating some indirection (thanks Taru Karttunen).
 * crypto/dsa: don't truncate input hashes.
 * doc/go_tutorial: make clear the file example is Unix-specific.
 * doc: add Defer, Panic, and Recover article,
 	add Error Handling article,
 	add Go 1 release notes document.
 * encoding/gob: better error messages when types mismatch.
 * env.bash: export CGO_ENABLED so cgo tests run (thanks Alex Brainman).
 * exp/sql: simplify some string conversions.
 * exp/ssh: Wait returns an *ExitError (thanks Gustav Paul).
 * exp/ssh: improve client channel close behavior (thanks Dave Cheney).
 * fmt: don't recur if String method (etc.) misbehaves.
 * gc: better error messages,
 	inlining (disabled without -l),
 	many bug fixes (thanks Lucio De Re and Rémy Oudompheng).
 * go/printer, godoc: print comments in example code.
 * go: implement doc, fmt, fix, list, vet, build, and install.
 * gobuilder: goinstall packages after building go tree.
 * godoc: &lt;pre&gt; must not occur inside &lt;p&gt; (thanks Olivier Duperray),
 	added an opensearch description document (thanks Christoph Hack),
 	text wrapping.
 * gofix: add httputil fix (thanks Yasuhiro Matsumoto).
 * gotest: use go/build more (thanks Robert Hencke).
 * gzip: convert between Latin-1 and Unicode (thanks Vadim Vygonets).
 * html/template: define the FuncMap type locally.
 * html: a first step at parsing foreign content (MathML, SVG),
 	more parser improvements (thanks Andrew Balholm).
 * http: close connection after printing panic stack trace (thanks Roger Peppe),
 	fix failing Transport HEAD request with gzip-looking response.
 * json: treat renamed byte slices the same as []byte.
 * ld: first pass at linker support for NetBSD binaries (thanks Christopher Nielsen),
 	fix memory leaks (thanks Scott Lawrence),
 	increase default stack size on Windows for cgo.
 * math: delete non-Sqrt-based Hypot,
 	implement, document, and fix special cases (thanks Charles L. Dorian),
 * misc/benchcmp: don't require "Benchmark" at beginning of line.
 * misc/osx: rename profile.go to profile_go (thanks Scott Lawrence).
 * net/http: fix trivial example server (thanks Olivier Duperray),
 	net/http: make test remove temporary file and directory.
 * net/smtp: add CRAM-MD5 authentication (thanks Vadim Vygonets).
 * reflect: fix Slice cap (thanks Gustavo Niemeyer).
 * regexp: performance improvements; avoid allocation of input interface.
 * runtime: bump gc 'extra bytes' check (thanks Christopher Wedgwood),
 	madvise and SysUnused for Linux (thanks Sébastien Paolacci),
 	make gc_test test extra allocated space, not total space,
 	support for NetBSD (thanks Christopher Nielsen).
 * spec: adjust complex constant example (thanks Robert Hencke),
 	values of underlying type uintptr can be converted to unsafe.Pointer,
 	var x = 'a' defaults to type rune.
 * strconv: include package and function name in error strings,
 	make QuoteRune etc. take a rune argument,
 	some performance improvements.
 * syscall: add constants for flock() system call under Linux,
 	regenerate z-files for darwin, freebsd (thanks Mikio Hara),
 	regenerate z-files for openbsd,
 	return error, not uintptr, when function returns error (thanks Alex Brainman).
 * test/bench: move to test/bench/shootout.
 * test/garbage: move to test/bench/garbage.
 * test: make array smaller in nilptr test.
 * time: allow sleep tests to run for 200% too long,
 	fix Time.Add (thanks Hector Chu),
 	fix daysIn for December (thanks Peter Mundy),
 	gob marshaler for Time (thanks Robert Hencke),
 	use Duration for AfterFunc.
 * various: a grab-bag of time.Duration cleanups.
 </pre>

 <h2 id="2011-12-06">2011-12-06</h2>

 <pre>
 This snapshot includes a language change and changes to the strconv and go/doc
 packages. The package changes require changes to client code.
 The language change is backwards-compatible.

 Type elision in arrays, slices, or maps of composite literals has been
 extended to include pointers to composite literals. Code like this
 	var t = []*T{&amp;T{}, &amp;T{}}
 may now be written as
 	var t = []*T{{}, {}}
 You can use gofmt -s to simplify such code.

 The strconv package has been given a more idiomatic and efficient interface.
 Client code can be updated with gofix. See the docs for the details:
 	http://weekly.golang.org/pkg/strconv/

 The go/doc package's ToHTML function now takes a []byte argument instead of a
 string.

 Other changes:
 * crypto/aes: eliminate some bounds checking and truncation (thanks Rémy Oudompheng).
 * crypto/x509: if a parent cert has a raw subject, use it.
 * encoding/gob: don't send type info for unexported fields.
 * exp/ssh: allow for msgUserAuthBanner during authentication (thanks Gustav Paul).
 * fmt: benchmark floating point,
 	only use Stringer or Error for strings.
 * gc: changes in export format in preparation of inlining,
 	disallow map/func equality via interface comparison,
 	use gofmt spacing when printing map type.
 * go/doc: exclude lines ending in ':' from possible headings.
 * gobuilder: -commit mode for packages,
 	cripple -package mode temporarily,
 	use new dashboard protocol.
 * godoc: improved output of examples in html (thanks Volker Dobler).
 * gofmt: handle &T in composite literal simplify.
 * goinstall: honour -install=false flag when -make=true.
 * hash: rewrite comment on Hash.Sum method.
 * html: more parser improvements (thanks Andrew Balholm).
 * image: avoid func comparison during ColorModel comparison.
 * math: add special-cases comments to Sinh and Tanh (thanks Charles L. Dorian).
 * misc/dashboard: further implementation work.
 * net, syscall: remove BindToDevice from UDPConn, IPConn (thanks Mikio Hara).
 * net/mail: correctly compare parsed times in the test.
 * os/exec: make LookPath always search CWD under Windows (thanks Benny Siegert).
 * runtime: prep for type-specific algorithms.
 * strconv: 34% to 63% faster conversions.
 </pre>

 <h2 id="2011-12-02">2011-12-02</h2>

 <pre>
 This weekly snapshot includes changes to the hash package and a gofix for the
 time and os.FileInfo changes in the last snapshot.

 The hash.Hash's Sum method has been given a []byte argument,
 permitting the user to append the hash to an existing byte slice.
 Existing code that uses Sum can pass nil as the argument.
 Gofix will make this change automatically.

 Other changes:
 * crypto/tls: cleanup certificate load on windows (thanks Alex Brainman).
 * exp/ssh: add Std{in,out,err}Pipe methods to Session (thanks Dave Cheney).
 * dashboard: don't choke on weird builder names.
 * exp/ssh: export type signal, now Signal (thanks Gustav Paul).
 * os: add ModeType constant to mask file type bits (thanks Gustavo Niemeyer).
 * text/template: replace Add with AddParseTree.
 * go/doc: detect headings and format them in html (thanks Volker Dobler).
 </pre>

 <h2 id="2011-12-01">2011-12-01</h2>

 <pre>
 This weekly snapshot includes changes to the time, os, and text/template
 packages. The changes to the time and os packages are significant and related.
 Code that uses package time, package text/template, or package os's FileInfo
 type will require changes.

 In package time, there is now one type - time.Time - to represent times.
 Note that time.Time should be used as a value, in contrast to old code
 which typically used a *time.Time, a pointer to a large struct.  (Drop the *.)
 Any function that previously accepted a *time.Time, an int64
 number of seconds since 1970, or an int64 number of nanoseconds
 since 1970 should now accept a time.Time.  Especially as a replacement
 for the int64s, the type is good documentation about the meaning of
 its value.

 Whether you were previously calling time.Seconds, time.Nanoseconds,
 time.LocalTime, or time.UTC, the replacement is the new function
 time.Now.

 If you previously wrote code like:

        t0 := time.Nanoseconds()
        myFunction()
        t1 := time.Nanoseconds()
        delta := t1 - t0
        fmt.Printf("That took %.2f seconds\n", float64(t1-t0)/1e9)

 you can now write:

        t0 := time.Now()
        myFunction()
        t1 := time.Now()
        delta := t1.Sub(t0)
        fmt.Printf("That took %s\n", delta)

 In this snippet, the variable delta is of the new type time.Duration, the
 replacement for the many int64 parameters that were nanosecond
 counts (but not since 1970).

 Gofix can do the above conversions and some others, but it does not
 rewrite explicit int64 types as time.Time. It is very likely that you will
 need to edit your program to change these types after running gofix.
 As always, be sure to read the changes that gofix makes using your
 version control system's diff feature.

 See http://weekly.golang.org/pkg/time/ for details.

 In package os, the FileInfo struct is replaced by a FileInfo interface,
 admitting implementations by code beyond the operating system.
 Code that refers to *os.FileInfo (a pointer to the old struct) should
 instead refer to os.FileInfo (the new interface).
 The interface has just a few methods:

        type FileInfo interface {
                Name() string       // base name of the file
                Size() int64        // length in bytes
                Mode() FileMode     // file mode bits
                ModTime() time.Time // modification time
                IsDir() bool        // abbreviation for Mode().IsDir()
        }

 If you need access to the underlying stat_t provided by the operating
 system kernel, you can access it by assuming that the FileInfo you are
 holding is actually an *os.FileStat, and that it's Sys field is actually a
 *syscall.Stat_t, as in:

        dev := fi.(*os.FileStat).Sys.(*syscall.Stat_t).Dev

 Of course, this is not necessarily portable across different operating
 systems.

 Gofix will take care of rewriting *os.FileInfo to os.FileInfo for you,
 and it will also rewrite expressions like fi.Name into calls like fi.Name().

 See http://weekly.golang.org/pkg/os/#FileInfo for details.

 The template package has been changed to export a new, simpler API.
 The Set type is gone. Instead, templates are automatically associated by
 being parsed together; nested definitions implicitly create associations.
 Only associated templates can invoke one another.
 This approach dramatically reduces the breadth of the construction API.
 The html/template package has been updated also.
 There's a gofix for the simplest and most common uses of the old API.
 Code that doesn't mention the Set type is likely to work after running gofix;
 code that uses Set will need to be updated by hand.
 The template definition language itself is unchanged.

 See http://weekly.golang.org/pkg/text/template/ for details.


 Other changes:
 * cgo: add support for callbacks from dynamic libraries.
 * codereview: gofmt check for non-src/ files (thanks David Crawshaw).
 * crypto/openpgp/packet: fix private key checksum.
 * crypto/tls: add openbsd root certificate location,
 	don't rely on map iteration order.
 * crypto/x509, crypto/tls: support PKCS#8 private keys.
 * dashboard: start of reimplementation in Go for App Engine.
 * encoding/xml: fix copy bug.
 * exp/gui: move exp/gui and exp/gui/x11 to http://code.google.com/p/x-go-binding
 * exp/ssh: various improvements (thanks Dave Cheney and Gustav Paul).
 * filepath/path: fix Rel buffer sizing (thanks Gustavo Niemeyer).
 * gc: fix Nconv bug (thanks Rémy Oudompheng) and other fixes.
 * go/printer, gofmt: performance improvements.
 * gofix: test and fix missorted renames.
 * goinstall: add -fix flag to run gofix on packages on build failure,
 	better error reporting,
 	don't hit network unless a checkout or update is required,
 	support Google Code sub-repositories.
 * html: parser improvements (thanks Andrew Balholm).
 * http: fix sniffing bug causing short writes.
 * json: speed up encoding, caching reflect calls.
 * ld: align ELF data sections.
 * math/big: fix destination leak into result value (thanks Roger Peppe),
 	use recursive subdivision for significant speedup.
 * math: faster Cbrt and Sincos (thanks Charles L. Dorian).
 * misc/osx: scripts to make OS X package and disk image (thanks Scott Lawrence).
 * os: fail if Open("") is called on windows (thanks Alex Brainman).
 * runtime: make sure stack is 16-byte aligned on syscall (thanks Alex Brainman).
 * spec, gc: allow direct conversion between string and named []byte, []rune.
 * sql: add Tx.Stmt to use an existing prepared stmt in a transaction,
 	more driver docs & tests; no functional changes.
 * strings: add ContainsAny and ContainsRune (thanks Scott Lawrence).
 * syscall: add SUSv3 RLIMIT/RUSAGE constants (thanks Sébastien Paolacci),
 	fix openbsd sysctl hostname/domainname workaround,
 	implement Syscall15 (thanks Alex Brainman).
 * time: fix Timer stop.
 </pre>

 <h2 id="2011-11-18">2011-11-18</h2>

 <pre>
 This snapshot includes some language changes.

 Map and function value comparisons are now disallowed (except for comparison
 with nil) as per the Go 1 plan. Function equality was problematic in some
 contexts and map equality compares pointers, not the maps' content.

 As an experiment, structs are now allowed to be copied even if they contain
 unexported fields. This gives packages the ability to return opaque values in
 their APIs.

 Other changes:
 * 6a, 8a: allow $(-1) for consistency with $1, $(1), $-1.
 * 6l: code generation fixes (thanks Michał Derkacz).
 * build: fix check for selinux allow_execstack on Fedora (thanks Bobby Powers).
 * builtin: document delete.
 * cgo: don't panic on undeclared enums/structs (thanks Rémy Oudompheng),
 	fix g0 stack guard.
 * crypto/tls: fix handshake message test.
 * crypto: update incorrect references to Cipher interface; should be Block.
 * doc: clean ups, additions, and fixes to several documents.
 * doc/install: add openbsd (thanks Joel Sing!).
 * doc: link to Chinese translation of A Tour of Go.
 * encoding/json: add marshal/unmarshal benchmark,
 	decode [] as empty slice, not nil slice,
 	make BenchmarkSkipValue more consistent.
 * env.bash: check for presence of make/gmake (thanks Scott Lawrence).
 * exp/sql: NumInput() allow -1 to ignore checking (thanks Yasuhiro Matsumoto),
 	add DB.Close, fix bugs, remove Execer on Driver (only Conn),
 	document that for drivers, io.EOF means no more rows,
 	add client side support for publickey auth (thanks Dave Cheney),
 	add direct-tcpip client support (thanks Dave Cheney),
 	change test listen address, also exit test if fails,
 	other fixes and improvements (thanks Dave Cheney).
 * exp/terminal: rename shell to terminal and add SetSize.
 * fcgi: fix server capability discovery.
 * fmt: distinguish empty vs nil slice/map in %#v.
 * gc: better error, type checks, and many fixes,
 	remove m[k] = x, false syntax (use delete(m, k) instead),
 	support for building with Plan 9 yacc (thanks Anthony Martin).
 * go/printer: make //line formatting idempotent.
 * godefs: delete, replaced by cgo -godefs.
 * godoc: document -templates flag, fix remote search,
 	provide mode for flat (non-indented) directory listings.
 * gofmt: leave nil nodes of the AST unchanged (thanks Rémy Oudompheng).
 * html/template: indirect top-level values before printing.
 * html: more parser improvements (thanks Andrew Balholm).
 * http: fix serving from CWD with http.ServeFile,
 	make Dir("") equivalent to Dir(".").
 * ld: fix .bss for ldpe (thanks Wei Guangjing).
 * math/big: replace nat{} -&gt; nat(nil).
 * math: faster Lgamma (thanks Charles L. Dorian).
 * mime: implement TypeByExtension for windows.
 * misc/bbedit: error and rune support (thanks Anthony Starks).
 * misc/benchcmp: benchmark comparison script.
 * misc/emacs: add delete builtin (thanks Bobby Powers).
 * misc/kate: add error and rune (thanks Evan Shaw).
 * misc/notepadplus: error and rune support (thanks Anthony Starks).
 * misc/windows: Windows installer in MSI format (thanks Joe Poirier).
 * net, io/ioutil: remove use of os.Time (thanks Anthony Martin).
 * net/http: fix EOF handling on response body (thanks Gustavo Niemeyer),
 	fix sniffing when using ReadFrom,
 	use t.Errorf from alternate goroutine in test.
 * os: remove undocumented Envs (use os.Environ instead).
 * reflect: empty slice/map is not DeepEqual to nil,
 	make Value an opaque struct.
 * runtime, syscall: convert from godefs to cgo.
 * runtime: add nanotime for Plan 9 (thanks Anthony Martin),
 	add timer support, use for package time,
 	avoid allocation for make([]T, 0).
 * strconv: add Ftoa benchmarks, make Ftoa faster.
 * syscall: delete syscall.Sleep, take over env implementation, use error.
 * testing: add file:line stamps to messages, print results to standard output.
 * text/template: refactor set parsing.
 * time: add ISOWeek method to Time (thanks Volker Dobler).
 * various: avoid func compare, reduce overuse of os.EINVAL + others.
 </pre>

 <h2 id="2011-11-09">2011-11-09</h2>

 <pre>
 This weekly snapshot renames various Go packages as described in the Go 1 plan.
 Import statements in client code can be updated automatically with gofix.

 The changes are:
 	asn1              -&gt; encoding/asn1
 	big               -&gt; math/big
 	cmath             -&gt; math/cmplx
 	csv               -&gt; encoding/csv
 	exec              -&gt; os/exec
 	exp/template/html -&gt; html/template
 	gob               -&gt; encoding/gob
 	http              -&gt; net/http
 	http/cgi          -&gt; net/http/cgi
 	http/fcgi         -&gt; net/http/fcgi
 	http/httptest     -&gt; net/http/httptest
 	http/pprof        -&gt; net/http/pprof
 	json              -&gt; encoding/json
 	mail              -&gt; net/mail
 	rpc               -&gt; net/rpc
 	rpc/jsonrpc       -&gt; net/rpc/jsonrpc
 	scanner           -&gt; text/scanner
 	smtp              -&gt; net/smtp
 	syslog            -&gt; log/syslog
 	tabwriter         -&gt; text/tabwriter
 	template          -&gt; text/template
 	template/parse    -&gt; text/template/parse
 	rand              -&gt; math/rand
 	url               -&gt; net/url
 	utf16             -&gt; unicode/utf16
 	utf8              -&gt; unicode/utf8
 	xml               -&gt; encoding/xml
 </pre>

 <h2 id="2011-11-08">2011-11-08</h2>

 <pre>
 This weekly snapshot includes some package changes.

 In preparation for the Go 1 package reorganziation the sources for various
 packages have been moved, but the import paths remain unchanged. This
 inconsistency breaks goinstall at this snapshot. If you use goinstall, please
 stay synced to the previous weekly snapshot until the next one is tagged.

 The Error methods in the html, bzip2, and sql packages that return error values
 have been renamed to Err.

 Some non-core parts of the http package have been moved to net/http/httputil.
 The Dump* and NewChunked* functions and ClientConn, ServerConn, and
 ReverseProxy types have been moved from http to httputil.

 The API for html/template is now a direct copy of the template API, instead of
 exposing a single Escape function. For HTML templates, simply use the
 html/template package as you would the template package.

 Other changes:
 * all: rename os.EOF to io.EOF in non-code contexts (thanks Vincent Vanackere),
 	sort imports with gofix.
 * archive/zip: close file opened with OpenReader (thanks Dmitry Chestnykh).
 * bufio: return nil line from ReadLine on error, as documented.
 * builtin: document basic types and the built-in error type.
 * bytes: add Contains function.
 * exp/sql: finish implementation of transactions, flesh out types, docs.
 * exp/ssh: improved client authentication support (thanks Dave Cheney).
 * gc: better error message for range over non-receive channel,
 	bug fixes and clean-ups,
 	detect type switch variable not used cases,
 	fix escaping of package paths in symbol names,
 	helpful error message on method call on pointer to pointer,
 	portably read archive headers (thanks Ron Minnich).
 * gob: fix bug when registering the same type multiple times.
 * gofix: avoid panic on body-less functions in netudpgroup,
 	make fix order implicit by date.
 * gofmt, gofix: sort imports.
 * goinstall: support launchpad.net/~user branches (thanks Jani Monoses).
 * gopack: do not look for Go metadata in non-Go objects.
 * gotest: don't run examples that have no expected output.
 * html: the parser bug fixing campaign continues (thanks Andrew Balholm).
 * http: fix whitespace handling in sniffer,
 	only recognize application/x-www-form-urlencoded in ParseForm,
 	support Trailers in ReadRequest.
 * lib9: add ctime.
 * math: faster Gamma (thanks Charles L. Dorian),
 	improved accuracy for Tan (thanks Charles L. Dorian),
 	improved high-angle test for Cos, Sin and Tan (thanks Charles L. Dorian).
 * net: implement LookupTXT for windows (thanks Alex Brainman).
 * os,text,unicode: renamings.
 * runtime/cgo: fix data declaration to be extern.
 * runtime: add timespec definition for freebsd,
 	add windows callback tests (thanks Alex Brainman),
 	fix prototype for openbsd thrsleep,
 	fix set and not used,
 	unify mutex code across OSes,
 	windows_386 sighandler to use correct g (thanks Alex Brainman).
 * template: format error with pointer receiver,
 	make redefinition of a template in a set more consistent.
 * test: clear execute bit from source file (thanks Mikio Hara),
 	make closedchan.go exit with failure if something fails.
 * time: faster Nanoseconds call.
 * websocket: return an error HTTP response for bad websocket request.
 * xml: allow parsing of &lt;_&gt; &lt;/_&gt;. (thanks David Crawshaw).
 </pre>

 <h2 id="2011-11-02">2011-11-02 (new error type)</h2>

 <pre>
 This snapshot introduces the built-in error type, defined as

        type error interface {
                Error() string
        }

 The error type replaces os.Error. Notice that the method name has changed from
 String to Error. Package fmt's Print formats both Stringers and errors:
 in general there is no need to implement both String and Error methods.

 Gofix can update most code. If you have split your package across many files,
 it may help to use the -force=error command-line option, which forces gofix to
 apply the error fix even if it is not obvious that a particular file needs it.
 As always, it is a good idea to read and test the changes that gofix made
 before committing them to your version control system.
 </pre>

 <h2 id="2011-11-01">2011-11-01</h2>

 <pre>
 * 6l: remove mention of -e flag - it does nothing.
 * cc: change cas to newcase (thanks Ron Minnich).
 * crypto/openpgp/error: use Error in names of error impl types.
 * crypto/rsa: change public exponent from 3 to 65537.
 * crypto/tls: add Error method to alert.
 * doc: add link to A Tour of Go in Japanese,
 	add 'all' make rule to build all docs,
 	refer to tour.golang.org instead of go-tour.appspot.com.
 * exp/norm: fixed bug that crept in with moving to the new regexp.
 * exp/ssh: fix length header leaking into channel data (thanks Dave Cheney).
 * fmt: handle os.Error values explicity (as distinct from Stringer).
 * gc: clean up printing,
 	fix [568]g -V crash (thanks Mikio Hara),
 	test + fix escape analysis bug.
 * go/build: avoid os.Error in tests.
 * go/doc: remove os.NewError anti-heuristic.
 * go/parser: test and fix := scoping bug.
 * gob: split uses of gobError, remove unnecessary embedding.
 * gofix: test import insertion, deletion.
 * goinstall: intelligent vcs selection for common sites (thanks Julian Phillips).
 * gopack: change archive file name length back to 16.
 * html: fix print argument in test,
 	more parser improvements (thanks Andrew Balholm).
 * json: properly handle nil slices (thanks Alexander Reece).
 * math: improved accuracy for Sin and Cos (thanks Charles L. Dorian).
 * misc/emacs: fix restoration of windows after gofmt (thanks Jan Newmarch).
 * misc/vim: add rune keyword (thanks Jongmin Kim).
 * misc/windows: can be used for amd64 (thanks Alex Brainman).
 * net: document why we do not use SO_REUSEADDR on windows (thanks Alex Brainman).
 * os: do not interpret 0-length read as EOF.
 * pkg: remove .String() from some print arguments.
 * rpc: avoid infinite loop on input error.
 * runtime/pprof: document OS X being broken.
 * runtime: lock the main goroutine to the main OS thread during init.
 * spec: define that initialization is sequential.
 * strconv: use better errors than os.EINVAL, os.ERANGE.
 * syscall: fix Await msg on Plan 9 (thanks Andrey Mirtchovski).
 * template: do not use error as stringer,
 	fix error checking on execute without parse (thanks Scott Lawrence).
 * test/alias.go: additional tests.
 * test: error-related fixes.
 * textproto: prevent long lines in HTTP headers from causing HTTP 400 responses.
 * time: add RFC1123 with numeric timezone format (thanks Scott Lawrence).
 </pre>

 <h2 id="2011-10-26">2011-10-26 (new rune type)</h2>

 <pre>
 This snapshot introduces the rune type, an alias for int that
 should be used for Unicode code points.

 A future release of Go (after Go 1) will change rune to be an
 alias for int32 instead of int.  Using rune consistently is the way
 to make your code build both before and after this change.

 To test your code for rune safety, you can rebuild the Go tree with

 	GOEXPERIMENT=rune32 ./all.bash

 which builds a compiler in which rune is an alias for int32 instead of int.

 Also, run govet on your code to identify methods that might need to have their
 signatures updated.
 </pre>

 <h2 id="2011-10-25">2011-10-25</h2>

 <pre>
 * big: make SetString return nil if an error occurs,
 	new Rat.Inv method,
 	usable zero Rat values without need for explicit initialization.
 * codereview: show LGTMs in hg p.
 * crypto/x509: fix names in certificate generation.
 * exp/ssh: add experimental ssh client,
 	introduce Session to replace Cmd for interactive commands,
 	server cleanups (thanks Dave Cheney).
 * exp/types: fix crash in parseBasicType on unknown type.
 * fmt: don't panic formatting nil interfaces (thanks Gustavo Niemeyer).
 * go/ast, go/token: actually run tests; fix go/ast test.
 * gotest: explicit -help flag, use $GCFLAGS like make does.
 * govet: check canonical dynamic method signatures.
 * html: improved parsing (thanks Andrew Balholm),
 	parse &lt;select&gt; tags, parse and render comment nodes,
 	remove the Tokenizer.ReturnComments option.
 * http: Transport: with TLS InsecureSkipVerify, skip hostname check.
 * misc/vim: add highlighting for delete (thanks Dave Cheney).
 * net: do not set SO_REUSEADDR for windows (thanks Alex Brainman).
 * os/inotify: move to exp/inotify (thanks Mikio Hara).
 * runtime: include bootstrap m in mcpu accounting (thanks Hector Chu).
 * syscall: use uintptr for Mount flags.
 </pre>

 <h2 id="2011-10-18">2011-10-18</h2>

 <pre>
 This weekly snapshot includes some language and package changes that may
 require code changes. Please read these notes carefully, as there are many
 changes and your code will likely be affected.

 The syntax for map deletion has been changed. Code that looks like:
 	m[x] = 0, false
 should be written as:
 	delete(m, x)
 The compiler still accepts m[x] = 0, false for now; even so, you can use gofix
 to rewrite such assignments into delete(m, x).

 The Go compiler will reject a return statement without arguments when any of
 the result variables has been shadowed. Code rejected as a result of this
 change is likely to be buggy.

 Receive-only channels (&lt;-chan T) cannot be closed.
 The compiler will diagnose such attempts.

 The first element of a map iteration is chosen at random. Code that depends on
 iteration order will need to be updated.

 Goroutines may be run during program initialization.

 A string may be appended to a byte slice. This code is now legal:
 	var b []byte
 	var s string
 	b = append(b, s...)

 The gotry command and its associated try package have been deleted.
 It was a fun experiment that - in the end - didn't carry its weight.

 The gotype tool has been moved to exp/gotype and its associated go/types
 package has been moved to exp/types. The deprecated go/typechecker package has
 been deleted.

 The enbflint tool has been moved to pkg/exp/ebnflint and its associated ebnf
 package has been moved to pkg/exp/ebnf.

 The netchan package has been moved to old/netchan.

 The http/spdy package has been moved to exp/spdy.

 The exp/datafmt package has been deleted.

 The container/vector package has been deleted. Slices are better:
 	http://code.google.com/p/go-wiki/wiki/SliceTricks

 Other changes:
 * 5l/6l/8l: correct ELFRESERVE diagnostic (thanks Anthony Martin).
 * 6l/8l: support OS X code signing (thanks Mikkel Krautz).
 * asn1: accept UTF8 strings as ASN.1 ANY values.
 * big: handle aliasing correctly for Rat.SetFrac.
 * build: add missing nuke target (thanks Anthony Martin),
 	catch future accidental dependencies to exp or old packages,
 	more robustly detect gold 2.20 (thanks Christopher Wedgwood),
 	pass $GCFLAGS to compiler,
 	stop on failed deps.bash.
 * crypto/tls: add 3DES ciphersuites,
 	add server side SNI support,
 	fetch root CA from Windows store (thanks Mikkel Krautz),
 	fetch root certificates using Mac OS API (thanks Mikkel Krautz),
 	fix broken looping code in windows root CA fetcher (thanks Mikkel Krautz),
 	more Unix root certificate locations.
 * crypto/x509: add code for dealing with PKIX public keys,
 	keep the raw Subject and Issuer.
 * csv: fix overly aggressive TrimLeadingSpace.
 * exp/ssh: general cleanups for client support (thanks Dave Cheney).
 * exp/template/html: fix bug in cssEscaper.
 * exp/terminal: split terminal handling from exp/ssh.
 * exp/winfsnotify: filesystem watcher for Windows (thanks Hector Chu).
 * fmt: fix test relying on map iteration order.
 * gc: changes to export format in preparation for inlining,
 	pass FlagNoPointers to runtime.new,
 	preserve uint8 and byte distinction in errors and import data,
 	stricter multiple assignment + test,
 	treat uintptr as potentially containing a pointer.
 * go/scanner: remove AllowIllegalChars mode.
 * go/token: document deserialization property.
 * gob: avoid one copy for every message written.
 * godefs: add enum/const testdata (thanks Dave Cheney).
 * godoc: generate package toc in template, not in JavaScript,
 	show "unexported" declarations when executing "godoc builtin",
 	show correct source name with -path.
 * gofix: make fix order explicit, add mapdelete.
 * gofmt: fix //line handling,
 	disallow rewrites for incomplete programs.
 * gotest: avoid conflicts with the name of the tested package (thanks Esko Luontola),
 	test example code.
 * goyacc: clean up after units (thanks Anthony Martin),
 	make more gofmt-compliant.
 * html: add a Render function, various bug fixes and improvements,
 	parser improvements (thanks Andrew Balholm).
 * http: DoS protection: cap non-Handler Request.Body reads,
 	RoundTrippers shouldn't mutate Request,
 	avoid panic caused by nil URL (thanks Anthony Martin),
 	fix read timeouts and closing,
 	remove Request.RawURL.
 * image/tiff: implement PackBits decoding (thanks Benny Siegert).
 * ld: fix "cannot create 8.out.exe" (thanks Jaroslavas Počepko).
 * misc/emacs: add a "godoc" command, like M-x man (thanks Evan Martin).
 * misc/swig: delete binaries (thanks Anthony Martin).
 * misc/windows: automated toolchain packager (thanks Joe Poirier).
 * net/windows: implement ip protocol name to number resolver (thanks Alex Brainman).
 * net: add File method to IPConn (thanks Mikio Hara),
 	allow LookupSRV on non-standard DNS names,
 	fix "unexpected socket family" error from WriteToUDP (thanks Albert Strasheim),
 	fix socket leak in case of Dial failure (thanks Chris Farmiloe),
 	remove duplicate error information in Dial (thanks Andrey Mirtchovski),
 	return error from CloseRead and CloseWrite (thanks Albert Strasheim),
 	skip ICMP test on Windows too unless uid 0.
 * reflect: disallow Interface method on Value obtained via unexported name,
 	make unsafe use of SliceHeader gc-friendly.
 * rpc: don't panic on write error.
 * runtime: faster strings,
 	fix crash if user sets MemProfileRate=0,
 	fix crash when returning from syscall during gc (thanks Hector Chu),
 	fix memory leak in parallel garbage collector.
 * scanner: invalidate scanner.Position when no token is present.
 * spec: define order of multiple assignment.
 * syscall/windows: dll function load and calling changes (thanks Alex Brainman).
 * syscall: add #ifdefs to fix the manual corrections in ztypes_linux_arm.go (thanks Dave Cheney),
 	adjust Mount to accomodate stricter FS implementations.
 * testing: fix time reported for failing tests.
 * utf8: add Valid and ValidString.
 * websocket: tweak hybi ReadHandshake to support Firefox (thanks Luca Greco).
 * xml: match Marshal's XMLName behavior in Unmarshal (thanks Chris Farmiloe).
 </pre>

 <h2 id="2011-10-06">2011-10-06</h2>

 <pre>
 This weekly snapshot includes changes to the io, image, and math packages that
 may require changes to client code.

 The io package's Copyn function has been renamed to CopyN.

 The math package's Fabs, Fdim, Fmax, Fmin and Fmod functions
 have been renamed to Abs, Dim, Max, Min, and Mod.

 Parts of the image package have been moved to the new image/color package.
 The spin-off renames some types. The new names are simply better:
 	image.Color              -&gt; color.Color
 	image.ColorModel         -&gt; color.Model
 	image.ColorModelFunc     -&gt; color.ModelFunc
 	image.PalettedColorModel -&gt; color.Palette
 	image.RGBAColor          -&gt; color.RGBA
 	image.RGBAColorModel     -&gt; color.RGBAModel
 	image.RGBA64Color        -&gt; color.RGBA64
 	image.RGBA64ColorModel   -&gt; color.RGBA64Model
 (similarly for NRGBAColor, GrayColorModel, etc)
 The image.ColorImage type stays in the image package, but is renamed:
 	image.ColorImage -&gt; image.Uniform
 The image.Image implementations (image.RGBA, image.RGBA64, image.NRGBA,
 image.Alpha, etc) do not change their name, and gain a nice symmetry:
 an image.RGBA is an image of color.RGBA, etc.
 The image.Black, image.Opaque uniform images remain unchanged (although their
 type is renamed from image.ColorImage to image.Uniform).
 The corresponding color types (color.Black, color.Opaque, etc) are new.
 Nothing in the image/ycbcr is renamed yet. The ycbcr.YCbCrColor and
 ycbcr.YCbCrImage types will eventually migrate to color.YCbCr and image.YCbCr,
 at a later date.

 * 5g/6g/8g: fix loop finding bug, fix -f(), registerize variables again.
 * 5l/6l/8l: add a DT_DEBUG dynamic tag to a dynamic ELF binary.
 * archive/zip: read and write unix file modes (thanks Gustavo Niemeyer).
 * build: clear execute bit from source files (thanks Mikio Hara).
 * bytes: add EqualFold.
 * cgo: allow Windows path characters in flag directives (thanks Joe Poirier),
 	support for mingw-w64 4.5.1 and newer (thanks Wei Guangjing).
 * codereview: extra repo sanity check,
 	fix for Mercurial 1.9.2,
 	fix hg change in Windows console (thanks Yasuhiro Matsumoto).
 * crypto/elliptic: use %x consistently in error print.
 * doc/spec: remove notes about gccgo limitations, now fixed.
 * doc: add 'Debugging Go code with GDB' tutorial,
 	fix memory model read visibility bug.
 * encoding/binary: PutX functions require buffer of sufficient size,
 	added benchmarks, support for varint encoding.
 * exec: add Command.ExtraFiles.
 * exp/sql{,/driver}: new database packages.
 * exp/ssh: move common code to common.go (thanks Dave Cheney).
 * exp/template/html: work continues.
 * fmt: replace channel cache with slice.
 * gc: limit helper threads based on ncpu.
 * go/doc, godoc, gotest: support for reading example documentation.
 * go: documentation and skeleton implementation of new command.
 * gob: protect against invalid message length,
 	allow sequential decoders on the same input stream.
 * hgpatch: do not use hg exit status (thanks Yasuhiro Matsumoto).
 * http: add Location method to Response,
 	don't send a 400 Bad Request after a client shutdown.
 * index/suffixarray: 4.5x faster index serialization (to memory).
 * io/ioutil: add a comment on why devNull is a ReaderFrom.
 * json: use strings.EqualFold instead of strings.ToLower.
 * misc/emacs: fix indent bug.
 * net: add shutdown: TCPConn.CloseWrite and CloseRead.
 * net: use AF_UNSPEC instead of individual address family (thanks Mikio Hara).
 * path/filepath: added Rel as the complement of Abs (thanks Gustavo Niemeyer).
 * pkg/syscall: add Mkfifo for linux platforms.
 * regexp: move to old/regexp, replace with exp/regexp, speedups.
 * runtime/gdb: fix pretty printing of channels,
 	gracefully handle not being able to find types.
 * runtime: check for nil value pointer in select syncsend case,
 	faster finalizers,
 	fix malloc sampling bug,
 	fix map memory leak,
 	fix spurious deadlock reporting,
 	fix usleep on linux/386 and re-enable parallel gc (thanks Hector Chu),
 	parallelize garbage collector mark + sweep.
 * strconv: faster Unquote in common case.
 * strings: add EqualFold, Replacer, NewReplacer.
 * suffixarray: add benchmarks for construction (thanks Eric Eisner).
 * syscall: add GetsockoptByte, SetsockoptByte for openbsd (thanks Mikio Hara),
 	add IPv4 ancillary data for linux (thanks Mikio Hara),
 	mark stdin, stdout, stderr non-inheritable by child processes (thanks Alex Brainman),
 	mksyscall_windows.pl creates non-syscall packages (thanks Jaroslavas Počepko),
 	update multicast socket options (thanks Mikio Hara).
 * testing: support for running tests in parallel (thanks Miki Tebeka).
 * time: make month/day name comparisons case insenstive.
 * unicode: fix make tables.
 * vim: Send GoFmt errors to a location list (thanks Paul Sbarra).
 * websocket: add hybi-13 support, add mutex to make websocket full-duplex.
 </pre>

 <h2 id="2011-09-21">2011-09-21</h2>

 <pre>
 This weekly contains several improvements, bug fixes, and new packages.

 * archive/tar: document Header fields and Type flags (thanks Mike Rosset).
 * bytes: fix Replace so it actually copies (thanks Gustavo Niemeyer).
 * cgo: use GOARCH from the environment (thanks Jaroslavas Počepko).
 * codereview: save CL messages in $(hg root)/last-change.
 * crypto/bcrypt: new package (thanks Jeff Hodges).
 * crypto/blowfish: exposing the blowfish key schedule (thanks Jeff Hodges).
 * doc: link to golang-france.
 * doc: when configuring gold for gccgo, use --enable-gold=default.
 * exp/norm: changed trie to produce smaller tables.
 * exp/ssh: new package,
 	refactor halfConnection to transport (thanks Dave Cheney).
 * exp/template/html: more fixes and improvements.
 * filepath: fix Glob to return no error on nonmatching patterns.
 * gc: disallow invalid map keys,
 	handle complex CONVNOP.
 * gob: allocation fixes.
 * godoc: simplify internal FileSystem interface.
 * http/cgi: clean up environment (thanks Yasuhiro Matsumoto).
 * http: always include Content-Length header, even for 0 (thanks Dave Grijalva),
 	check explicit wrong Request.ContentLength values,
 	fix TLS handshake blocking server accept loop,
 	prevent DumpRequest from adding implicit headers.
 * httptest: add NewUnstartedServer.
 * json: clearer Unmarshal doc,
 	skip nil in UnmarshalJSON and (for symmetry) MarshalJSON.
 * net: use /etc/hosts first when looking up IP addresses (thanks Andrey Mirtchovski).
 * reflect: add comment about the doubled semantics of Value.String.
 * runtime: implement pprof support for windows (thanks Hector Chu),
 	increase stack system space on windows/amd64 (thanks Hector Chu).
 * suffixarray: generate less garbage during construction (thanks Eric Eisner),
 	improved serialization code using gob instead of encoding/binary.
 * sync/atomic: replace MFENCE with LOCK XADD.
 </pre>

 <h2 id="2011-09-16">2011-09-16</h2>

 <pre>
 This weekly snapshot includes changes to the image, path/filepath, and time
 packages. Code that uses these packages may need to be updated.

 The image package's NewX functions (NewRGBA, NewNRGBA, etc) have been changed
 to take a Rectangle argument instead of a width and height.
 Gofix can make these changes automatically.

 The path/filepath package's Walk function has been changed to take a WalkFunc
 function value instead of a Visitor interface value. WalkFunc is like the
 Visitor's VisitDir and VisitFile methods except it handles both files and
 directories:
 	func(path string, info *os.FileInfo, err os.Error) os.Error
 To skip walking a directory (like returning false from VisitDir) the WalkFunc
 must return SkipDir.

 The time package's Time struct's Weekday field has been changed to a method.
 The value is calculated on demand, avoiding the need to re-parse
 programmatically-constructed Time values to find the correct weekday.

 There are no gofixes for the filepath or time API changes, but instances of the
 old APIs will be caught by the compiler. The Weekday one is easy to update by
 hand. The Walk one may take more consideration, but will have fewer instances
 to fix.

 * build: add build comments to core packages.
 * codereview: Mercurial 1.9 fix for hg diff @nnn.
 * crypto/tls: handle non-TLS more robustly,
 	support SSLv3.
 * debug/elf: permit another case of SHT_NOBITS section overlap in test.
 * exm/template/html: more work on this auto-escaping HTML template package.
 * exp/norm: added regression test tool for the standard Unicode test set.
 * exp/regexp/syntax: fix invalid input parser crash,
 	import all RE2 parse tests + fix bugs.
 * exp/regexp: add MustCompilePOSIX, CompilePOSIX, leftmost-longest matching.
 * flag: make zero FlagSet useful.
 * gc: clean up if grammar.
 * go/build: handle cgo, // +build comments.
 * go/printer: use panic/defer instead of goroutine for handling errors.
 * go/token: support to serialize file sets.
 * godoc, suffixarray: switch to exp/regexp.
 * godoc: show packages matching a query at the top,
 	support for complete index serialization,
 	use go/build to find files in a package.
 * gofmt: accept program fragments on standard input, add else test.
 * http/cgi: add openbsd environment configuration.
 * http: document that Response.Body is non-nil.
 * image/png: don't use a goroutine to decode, to permit decode during init.
 * json: if a field's tag is "-", ignore the field for encoding and decoding.
 * ld: grow dwarf includestack on demand.
 * net, syscall: implement SetsockoptIPMReq(), and
 	move to winsock v2.2 for multicast support (thanks Paul Lalonde).
 * net: add a LookupTXT function.
 * os: os.RemoveAll to check for wboth error codes on Windows (thanks Jaroslavas Počepko).
 * path/filepath: fix Visitor doc (thanks Gustavo Niemeyer),
 	make UNC file names work (thanks Yasuhiro Matsumoto).
 * runtime: optimizations to channels on Windows (thanks Hector Chu),
 	syscall to return both AX and DX for windows/386 (thanks Alex Brainman).
 * sync/atomic: add 64-bit Load and Store.
 * syscall: add route flags for linux (thanks Mikio Hara).
 * test: add test for inheriting private method from anonymous field.
 * websocket: fix infinite recursion in Addr.String() (thanks Tarmigan Casebolt),
 	rename websocket.WebSocketAddr to *websocket.Addr.
 </pre>

 <h2 id="2011-09-07">2011-09-07</h2>

 <pre>
 This weekly snapshot consists of improvements and bug fixes, including fixes
 for issues introduced by escape analysis changes in the gc compiler.

 * build: clear execute bit from Go files (thanks Mike Rosset),
 	error out if problem with sudo.bash /usr/local/bin (thanks Mike Rosset).
 * exp/norm: add Reader and Writer,
 	performance improvements of quickSpan.
 * exp/regexp: bug fixes and RE2 tests.
 * exp/template/html: string replacement refactoring,
 	tweaks to js{,_test}.go.
 * gc: add -p flag to catch import cycles earlier,
 	fix label recursion bugs,
 	fix zero-length struct eval,
 	zero stack-allocated slice backing arrays,
 * gc, ld: fix Windows file paths (thanks Hector Chu).
 * go/parser: accept corner cases of signature syntax.
 * gobuilder: ignore _test.go files when looking for docs, more logging.
 * godoc: minor tweaks for App Engine use.
 * gofix: do not convert url in field names (thanks Gustavo Niemeyer).
 * gofmt: indent multi-line signatures.
 * gopprof: regexp fixes (thanks Hector Chu).
 * image/png: check zlib checksum during Decode.
 * libmach: fix incorrect use of memset (thanks Dave Cheney).
 * misc/goplay: fix template output.
 * net: ParseCIDR returns IPNet instead of IPMask (thanks Mikio Hara),
 	sync CIDRMask code, doc.
 * os: use GetFileAttributesEx to implement Stat on windows (thanks Alex Brainman).
 * runtime: fix openbsd 386 raisesigpipe,
 	implement exception handling on windows/amd64 (thanks Hector Chu),
 	test for concurrent channel consumers (thanks Christopher Wedgwood).
 * sort: use heapsort to bail out quicksort (thanks Ziad Hatahet).
 * sync/atomic: add LoadUintptr, add Store functions.
 * syscall: update routing message attributes handling (thanks Mikio Hara).
 * template: fix deadlock,
 	indirect or dereference function arguments if necessary,
 	slightly simplify the test for assignability of arguments.
 * url: handle ; in ParseQuery.
 * websocket: fix incorrect prints found by govet (thanks Robert Hencke).
 </pre>

 <h2 id="2011-09-01">2011-09-01</h2>

 <pre>
 This weekly contains performance improvements and bug fixes.

 The gc compiler now does escape analysis, which improves program performance
 by placing variables on the call stack instead of the heap when it is safe to
 do so.

 The container/vector package is deprecated and will be removed at some point
 in the future.

 Other changes:
 * archive/tar: support symlinks. (thanks Mike Rosset)
 * big: fix nat.scan bug. (thanks Evan Shaw)
 * bufio: handle a "\r\n" that straddles the buffer.
 	add openbsd.
 	avoid redundant bss declarations.
 	fix unused parameters.
 	fix windows/amd64 build with newest mingw-w64. (thanks Hector Chu)
 * bytes: clarify that NewBuffer is not for beginners.
 * cgo: explain how to free something.
 	fix GoBytes. (thanks Gustavo Niemeyer)
 	fixes callback for windows amd64. (thanks Wei Guangjing)
 	note that CString result must be freed. (thanks Gustavo Niemeyer)
 * cov: remove tautological #defines. (thanks Lucio De Re)
 * dashboard: yet another utf-8 fix.
 * doc/codelab/wiki: fix Makefile.
 * doc/progs: fix windows/amd64. (thanks Jaroslavas Počepko)
 * doc/tmpltohtml: update to new template package.
 * doc: emphasize that environment variables are optional.
 * effective_go: convert to use tmpltohtml.
 * exp/norm: reduced the size of the byte buffer used by reorderBuffer by half by reusing space when combining.
 	a few minor fixes to support the implementation of norm.
 	added implementation for []byte versions of methods.
 * exp/template/html: add some tests for ">" attributes.
 	added handling for URL attributes.
 	differentiate URL-valued attributes (such as href).
 	reworked escapeText to recognize attr boundaries.
 * exp/wingui: made compatible with windows/amd64. (thanks Jaroslavas Počepko)
 * flag: add Parsed, restore Usage.
 * gc: add openbsd.
 	escape analysis.
 	fix build on Plan 9. (thanks Lucio De Re)
 	fix div bug.
 	fix pc/line table. (thanks Julian Phillips)
 	fix some spurious leaks.
 	make static initialization more static.
 	remove JCXZ; add JCXZW, JCXZL, and JCXZQ instructions. (thanks Jaroslavas Počepko)
 	shuffle #includes.
 	simplify escape analysis recursion.
 	tweak and enable escape analysis.
 * go/ast cleanup: base File/PackageExports on FilterFile/FilterPackage code.
 	adjustments to filter function.
 	fix ast.MergePackageFiles to collect infos about imports. (thanks Sebastien Binet)
 	generalize ast.FilterFile.
 * go/build: add test support & use in gotest.
 	separate test imports out when scanning. (thanks Gustavo Niemeyer)
 * go/parser: fix type switch scoping.
 	fix type switch scoping.
 * gob: explain that Debug isn't useful unless it's compiled in.
 * gobuilder: increase log limit.
 * godashboard: fix utf-8 in user names.
 * godoc: first step towards reducing index size.
 	add dummy playground.js to silence godoc warning at start-up.
 	added systematic throttling to indexing goroutine.
 	fix bug in zip.go.
 	support for reading/writing (splitted) index files.
 	use virtual file system when generating package synopses.
 * gofix: forgot to rename the URL type.
 	osopen: fixed=true when changing O_CREAT. (thanks Tarmigan Casebolt)
 * goinstall: error out with paths that end with '/'. (thanks Tarmigan Casebolt)
 	report lack of $GOPATH on errors. (thanks Gustavo Niemeyer)
 	select the tag that is closest to runtime.Version.
 * gotry: add missing $. (thanks Tarmigan Casebolt)
 * http: add MaxBytesReader to limit request body size.
 	add file protocol transport.
 	adjust test threshold for larger suse buffers.
 	delete error kludge.
 	on invalid request, send 400 response.
 	return 413 instead of 400 when the request body is too large. (thanks Dave Cheney)
 	support setting Transport's TLS client config.
 * image/tiff: add a decode benchmark. (thanks Benny Siegert)
 	decoder optimization. (thanks Benny Siegert)
 * image: add PalettedImage interface, and make image/png recognize it. (thanks Jaroslavas Počepko)
 * io: add TeeReader. (thanks Hector Chu)
 * json: add struct tag option to wrap literals in strings.
 	calculate Offset for Indent correctly. (thanks Jeff Hodges)
 	fix decode bug with struct tag names with ,opts being ignored.
 * ld: handle Plan 9 ar format. (thanks Lucio De Re)
 	remove duplicate bss definitions.
 * libmach: support reading symbols from Windows .exe for nm. (thanks Mateusz Czapliński)
 * math: fix Pow10 loop. (thanks Volker Dobler)
 * mime: ParseMediaType returns os.Error now, not a nil map.
 	media type formatter. (thanks Pascal S. de Kloe)
 	text charset defaults. (thanks Pascal S. de Kloe)
 * misc/dashboard: remove limit for json package list.
 * misc/emacs: refine label detection.
 * net: add ParseMAC function. (thanks Paul Borman)
 	change the internal form of IPMask for IPv4. (thanks Mikio Hara)
 	disable "tcp" test on openbsd.
 	fix windows build. (thanks Alex Brainman)
 	join and leave a IPv6 group address, on a specific interface. (thanks Mikio Hara)
 	make use of IPv4len, IPv6len. (thanks Mikio Hara)
 	move internal string manipulation routines to parse.go. (thanks Mikio Hara)
 * os: disable Hostname test on OpenBSD.
 	fix WNOHANG Waitmsg. (thanks Gustavo Niemeyer)
 * reflect: add Value.Bytes, Value.SetBytes methods.
 * rpc: add benchmark for async rpc calls.
 * runtime: add openbsd 386 defs.h.
 	add runtime support for openbsd 386.
 	add runtime· prefix to showframe.
 	ctrlhandler for windows amd64. (thanks Wei Guangjing)
 	fix stack cleanup on windows/amd64. (thanks Hector Chu)
 	fix void warnings.
 	go interface to cdecl calbacks. (thanks Jaroslavas Počepko)
 	handle string + char literals in goc2c.
 	make arm work on Ubuntu Natty qemu.
 	openbsd thread tweaks.
 	simplify stack traces.
 	speed up cgo calls. (thanks Alex Brainman)
 	use cgo runtime functions to call windows syscalls. (thanks Alex Brainman)
 	windows/amd64 callbacks fixed and syscall fixed to allow using it in callbacks. (thanks Jaroslavas Počepko)
 * strconv: put decimal on stack.
 * spec: update section on Implementation Differences.
 * syscall: SOMAXCONN should be 0x7fffffff at winsock2. (thanks Yasuhiro Matsumoto)
 	add openbsd 386.
 	handle RTM_NEWROUTE in ParseNetlinkRouteAttr on Linux. (thanks Albert Strasheim)
 	handle routing entry in ParseRoutingSockaddr on BSD variants. (thanks Mikio Hara)
 	openbsd amd64 syscall support.
 	use the vdso page on linux x86 for faster syscalls instead of int $0x80. (thanks Yuval Pavel Zholkover)
 * template/parse: give if, range, and with a common representation.
 * template: grammar fix for template documentation. (thanks Bill Neubauer)
 	range over channel.
 	remove else and end nodes from public view.
 * test: put GOROOT/bin before all others in run.
 * time: fix Plan 9 build. (thanks Fazlul Shahriar)
 	fix zone during windows test.
 * type switches: test for pathological case.
 * version.bash: update VERSION on -save if already present. (thanks Gustavo Niemeyer)
 * websocket: implements new version of WebSocket protocol. (thanks Fumitoshi Ukai)
 * windows/386: clean stack after syscall. (thanks Jaroslavas Počepko)
 * xml: marshal "parent>child" tags correctly. (thanks Ross Light)
 </pre>

 <h2 id="2011-08-17">2011-08-17 (<a href="release.html#r60">base for r60</a>)</h2>

 <pre>
 This weekly contains some package re-shuffling. Users of the http and
 template packages may be affected.

 This weekly replaces the template package with exp/template.
 The original template package is still available as old/template.
 The old/template package is deprecated and will be removed at some point
 in the future. The Go tree has been updated to use the new template package.
 We encourage users of the old template package to switch to the new one.
 Code that uses template or exp/template will need to change
 its import lines to "old/template" or "template", respectively.

 The http package's URL parsing and query escaping code (such as ParseURL and
 URLEscape) has been moved to the new url package, with several simplifications
 to the names. Client code can be updated automatically with gofix.

 * asn1: support unmarshalling structs with int32 members (thanks Dave Cheney).
 * build: allow builds without cgo or hg,
 	support versioning without hg (thanks Gustavo Niemeyer).
 * builtin: add documentation for builtins.
 * cgo: omit duplicate symbols in writeDefs (thanks Julian Phillips).
 * misc: add support for OpenBSD.
 * doc/codewalk: new Markov chain codewalk.
 * exp/norm: added trie lookup code and associated tests,
 	generate trie struct in triegen.go for better encapsulation,
 	implementation of decomposition and composing functionality.
 * exp/template/html: new experimental package for auto-escaping HTML templates.
 * exp/template: don't panic on range of nil interface,
 	rename Parse*File and Parse*Files for clarity,
 	support field syntax on maps (thanks Gustavo Niemeyer), and
 	many other fixes and changes.
 * gc: implement nil chan and nil map support.
 * go/parser: range clause and type literal fixes.
 * godoc: show all top-level decls for (fake) package builtin.
 * goinstall: really report all newly-installed public packages.
 * html: parse more malformed tags.
 * http: fix ParseMultipartForm after MultipartReader error,
 	fix side effects in DefaultTransport's RoundTrip method (thanks Dave Grijalva).
 * json: fix []unmarshaler case.
 * ld: make addaddrplus4 static (thanks Lucio De Re).
 * syscall: move multicast address handling to the net package.
 * net: Plan 9 support (thanks Fazlul Shahriar),
 	add SetTimeout to Listener interface (thanks Aleksandar Dezelin),
 	add multicast stubs for OpenBSD,
 	return correct local address for an accepted TCP connection (thanks Mikio Hara).
 * reflect: panic on Invalid Interface call (thanks Gustavo Niemeyer).
 * rpc: implement ServeRequest to synchronously serve a single request,
 	make Server.Mutex unexported.
 * runtime: better checks for syscall.NewCallback parameter (thanks Alex Brainman),
 	correct SEH installation during callbacks (thanks Alex Brainman),
 	fix GC bitmap corruption,
 	fix pseudo-randomness on some selects (thanks Gustavo Niemeyer).
 * syscall: make LazyDLL/LazyProc.Mutex unexported.
 * test: allow multiple patterns in errchk,
 	new nil semantics.
 * time: take fractional seconds even if not in the format string.
 * url: new package.
 * utf8: rename some internal constants to remove leading underscores.
 * xml: escape string chardata in xml.Marshal.
 </pre>

 <h2 id="2011-08-10">2011-08-10</h2>

 <pre>
 This weekly contains performance improvements and bug fixes.

 There are no outward-facing changes, but imports of the old-style
 container/vector package have also been removed from the core library (thanks
 John Asmuth, Kyle Consalus).

 Other changes:

 * 5g: fix set but not used error (thanks Dave Cheney).
 * cmd/ld: Corrected mismatched print formats and variables (thanks Lucio De Re).
 * errchk: add -0 flag.
 * exp/norm: fix build by adding a test placeholder,
 	maketables tool for generating tables for normalization.
 * exp/template: bug fixes,
 	ensure that a valid Set is returned even on error (thanks Roger Peppe),
 	make index on maps return zero when key not present (thanks Roger Peppe),
 	split the parse tree into a separate package exp/template/parse,
 	add url query formatting filter.
 * faq: lots of small tweaks plus a couple of new discussions,
 	variant types, unions.
 * fmt: call UpdateMemStats in malloc counter.
 * go/build: use GOBIN as binary path for GOROOT.
 * gob: add UpdateMemStats calls to malloc counter,
 	avoid a couple of init-time allocations,
 	don't invoke GobEncoder on zero values.
 * gofmt: update test script so 'make test' succeeds.
 * html: parse doctype tokens; merge adjacent text nodes.
 * http: add more MPEG-4 MIME types to sniffer, and disable MP4 sniffing,
 	add test to serve content in index.html (thanks Yasuhiro Matsumoto),
 	configurable and default request header size limit,
 	correct format flags when printing errors in tests (thanks Alex Brainman),
 	correct path to serve index.html (thanks Yasuhiro Matsumoto),
 * ld: add one empty symbol into pe to make dumpbin works (thanks Wei Guangjing),
 	fail linking if the top-level package is not main.
 * misc/vim: godoc command (thanks Yasuhiro Matsumoto).
 * net: add support for openbsd (thanks Joel Sing),
 	fix /proc/net/igmp,igmp6 reading bug on linux (thanks Mikio Hara),
 	implement windows LookupMX and LookupAddr (thanks Mikio Hara),
 	sort SRV records before returning from LookupSRV (thanks Alex Brainman),
 * os: add support for openbsd (thanks Joel Sing).
 * runtime: add more specialized type algorithms,
 	correct Note documentation,
 	faster chan creation on Linux/FreeBSD/Plan9,
 	openbsd amd64 runtime support (thanks Joel Sing),
 	remove unnecessary locking (thanks Hector Chu).
 * scanner: correct error position for illegal UTF-8 encodings.
 * syscall: delay load of dll functions on Windows (thanks Alex Brainman),
 	move BSD mmap syscall (thanks Joel Sing),
 	update routing message support for BSD variants (thanks Mikio Hara).
 * test/bench: note changes after recent improvements to locking and runtime.
 * time: add nanoseconds to the Time structure,
 	parse and format fractional seconds.
 </pre>

 <h2 id="2011-07-29">2011-07-29</h2>

 <pre>
 This weekly contains performance improvements and many bug fixes.

 * 6l: OpenBSD support.
 * archive/zip: handle zip files with more than 65535 files,
 	more efficient reader and bug fix.
 * big: refine printf formatting and optimize string conversion.
 * build: fixes for mingw-w64 (thanks Wei Guangjing),
 	miscellaneous fixes.
 * cgo: add GoBytes, fix gmp example.
 * exp/norm: API for normalization library.
 * exp/regexp: implement regexp API using exp/regexp/syntax.
 * exp/template: more tweaks and fixes, convert the tree to use exp/template.
 * fmt: handle precision 0 format strings in standard way.
 * gc: a raft of bug fixes.
 * go/parser: report illegal label declarations at ':'.
 * gob: send empty but non-nil maps.
 * godoc: allow form feed in text files,
 	app engine configuration and updated documentation.
 * goinstall: abort and warn when using any url scheme, not just 'http://',
 	write to goinstall.log in respective GOPATH.
 * html: handle character entities without semicolons (thanks Andrew Balholm),
 	parse misnested formatting tags according to the HTML5 spec,
 	sync html/testdata/webkit with upstream WebKit.
 * http: content-type sniffing,
 	make serveFile redirects relative (thanks Andrew Balholm),
 	other fixes.
 * image/tiff: Do not panic when RowsPerStrip is missing (thanks Benny Siegert).
 * io/ioutil: improve performance of ioutil.Discard (thanks Mike Solomon).
 * ld: detect all import cycles,
 	ldpe fixes (thanks Wei Guangjing),
 	remove cseekend and redo pe writing (thanks Alex Brainman),
 	remove overlap of ELF sections on dynamic binaries (thanks Gustavo Niemeyer).
 * net/textproto: avoid 1 copy in ReadLine, ReadContinuedLine.
 * net: fix memory corruption in windows *netFD.ReadFrom (thanks Alex Brainman).
 * runtime: faster entersyscall/exitsyscall,
 	fix scheduler races (thanks Hector Chu),
 	higher goroutine arg limit, clearer error,
 	parallelism-related performance optimizations and fixes,
 	replace byte-at-a-time zeroing loop with memclr (thanks Quan Yong Zhai).
 * sort: fix Float64Slice sort; NaN smallest value (thanks Florian Uekermann).
 * src: removed some uses of container/vector (thanks John Asmuth).
 * sync: improve Once fast path.
 * unicode: fix case-mapping for roman numerals.
 </pre>

 <h2 id="2011-07-19">2011-07-19</h2>

 <pre>
 This weekly snapshot includes a language change and a change to the image
 package that may require changes to client code.

 The language change is that an "else" block is now required to have braces
 except if the body of the "else" is another "if". Since gofmt always puts those
 braces in anyway, programs will not be affected unless they contain "else for",
 "else switch", or "else select". Run gofmt to fix any such programs.

 The image package has had significant changes made to the Pix field of struct
 types such as image.RGBA and image.NRGBA. The image.Image interface type has
 not changed, though, and you should not need to change your code if you don't
 explicitly refer to Pix fields. For example, if you decode a number of images
 using the image/jpeg package, compose them using image/draw, and then encode
 the result using image/png, then your code should still work as before.

 If you do explicitly refer to Pix fields, there are two changes.  First, Pix[0]
 now refers to the pixel at Bounds().Min instead of the pixel at (0, 0). Second,
 the element type of the Pix slice is now uint8 instead of image.FooColor. For
 example, for an image.RGBA, the channel values will be packed R, G, B, A, R, G,
 B, A, etc. For 16-bits-per-channel color types, the pixel data will be stored
 as big-endian uint8s.

 Most Pix field types have changed, and so if your code still compiles after
 this change, then you probably don't need to make any further changes (unless
 you use an image.Paletted's Pix field). If you do get compiler errors, code
 that used to look like this:

 	// Get the R, G, B, A values for the pixel at (x, y).
 	var m *image.RGBA = loadAnImage()
 	c := m.Pix[y*m.Stride + x]
 	r, g, b, a := c.R, c.G, c.B, c.A

 should now look like this:

 	// Get the R, G, B, A values for the pixel at (x, y).
 	var m *image.RGBA = loadAnImage()
 	i := (y-m.Rect.Min.Y)*m.Stride + (x-m.Rect.Min.X)*4
 	r := m.Pix[i+0]
 	g := m.Pix[i+1]
 	b := m.Pix[i+2]
 	a := m.Pix[i+3]

 This image package change will not be fixed by gofix: how best to translate
 code into something efficient and idiomatic depends on the surrounding context,
 and is not easily automatable. Examples of what to do can be found in the
 changes to image/draw/draw.go in http://codereview.appspot.com/4675076/

 Other changes:
 * 6l: change default output name to 6.out.exe on windows (thanks Alex Brainman).
 * archive/zip: add Writer,
 	add Mtime_ns function to get modified time in sensible format.
 * cc, ld, gc: fixes for Plan 9 build (thanks Lucio De Re).
 * cgi: close stdout reader pipe when finished.
 * cgo: add missing semicolon in generated struct,
 	windows amd64 port (thanks Wei Guangjing).
 * codereview: fix for Mercurial 1.9.
 * dashboard: list "most installed this week" with rolling count.
 * debug/elf: read ELF Program headers (thanks Matthew Horsnell).
 * debug/pe: fixes ImportedSymbols for Win64 (thanks Wei Guangjing).
 * debug/proc: remove unused package.
 * doc/talks/io2010: update with gofix and handle the errors.
 * exp/eval, exp/ogle: remove packages eval and ogle.
 * exp/regexp/syntax: add Prog.NumCap.
 * exp/template: API changes, bug fixes, and tweaks.
 * flag: make -help nicer.
 * fmt: Scan(&amp;int) was mishandling a lone digit.
 * gc: fix closure bug,
 	fix to build with clang (thanks Dave Cheney),
 	make size of struct{} and [0]byte 0 bytes (thanks Robert Hencke),
 	some enhancements to printing debug info.
 * gif: fix local color map and coordinates.
 * go/build: fixes for windows (thanks Alex Brainman),
 	include processing of .c files for cgo packages (thanks Alex Brainman),
 	less aggressive failure when GOROOT not found.
 * go/printer: changed max. number of newlines from 3 to 2.
 * gob: register more slice types (thanks Bobby Powers).
 * godoc: support for file systems stored in .zip files.
 * goinstall, dashboard: Google Code now supports git (thanks Tarmigan Casebolt).
 * hash/crc32: add SSE4.2 support.
 * html: update section references in comments to the latest HTML5 spec.
 * http: drain the pipe output in TestHandlerPanic to avoid logging deadlock,
 	fix Content-Type of file extension (thanks Yasuhiro Matsumoto),
 	implement http.FileSystem for zip files,
 	let FileServer work when path doesn't begin with a slash,
 	support for periodic flushing in ReverseProxy.
 * image/draw: add benchmarks.
 * json: add omitempty struct tag option,
 	allow using '$' and '-' as the struct field's tag (thanks Mikio Hara),
 	encode \r and \n in strings as e.g. "\n", not "\u000A" (thanks Evan Martin),
 	escape < and > in any JSON string for XSS prevention.
 * ld: allow seek within write buffer<
 	add a PT_LOAD PHDR entry for the PHDR (thanks David Anderson).
 * net: windows/amd64 port (thanks Wei Guangjing).
 * os: plan9: add Process.Signal as a way to send notes (thanks Yuval Pavel Zholkover).
 * os: don't permit Process.Signal after a successful Wait.
 * path/filepath: fixes for windows paths (thanks Alex Brainman).
 * reflect: add Value.NumMethod,
 	panic if Method index is out of range for a type.
 * runtime: faster entersyscall, exitsyscall,
 	fix panic for make(chan [0]byte),
 	fix subtle select bug (thanks Hector Chu),
 	make goc2c build on Plan 9 (thanks Lucio De Re),
 	make TestSideEffectOrder work twice,
 	several parallelism-related optimizations and fixes,
 	stdcall_raw stack 16byte align for Win64 (thanks Wei Guangjing),
 	string-related optimizations (thanks Quan Yong Zhai),
 	track running goroutine count.
 * strconv: handle [-+]Infinity in atof.
 * sync: add fast paths to WaitGroup,
 	improve RWMutex performance.
 * syscall: add Flock on Linux,
 	parse and encode SCM_RIGHTS and SCM_CREDENTIALS (thanks Albert Strasheim).
 </pre>

 <h2 id="2011-07-07">2011-07-07 (<a href="release.html#r59">base for r59</a>)</h2>

 <pre>
 This weekly snapshot includes changes to the strings, http, reflect, json, and
 xml packages. Code that uses these packages will need changes. Most of these
 changes can be made automatically with gofix.

 The strings package's Split function has itself been split into Split and
 SplitN. SplitN is the same as the old Split. The new Split is equivalent to
 SplitN with a final argument of -1.

 The http package has a new FileSystem interface that provides access to files.
 The FileServer helper now takes a FileSystem argument instead of an explicit
 file system root. By implementing your own FileSystem you can use the
 FileServer to serve arbitrary data.

 The reflect package supports a new struct tag scheme that enables sharing of
 struct tags between multiple packages.
 In this scheme, the tags must be of the form:
         key:"value" key2:"value2"
 reflect.StructField's Tag field now has type StructTag (a string type), which
 has method Get(key string) string that returns the associated value.
 Clients of json and xml will need to be updated. Code that says
         type T struct {
                 X int "name"
         }
 should become
         type T struct {
                 X int `json:"name"`  // or `xml:"name"`
         }
 Use govet to identify struct tags that need to be changed to use the new syntax.

 Other changes:
 * 5l, 6l, 8l: drop use of ed during build.
 * asn1: support T61 and UTF8 string.
 * bufio: do not cache Read errors (thanks Graham Miller).
 * build: make version.bash aware of branches.
 * cgi: don't depend on CGI.pm for tests.
 * codereview: make --ignore_hgpatch_failure work again,
 	restrict sync to default branch.
 * crypto/openpgp: add ability to reserialize keys,
 	bug fix (thanks Gideon Jan-Wessel Redelinghuys).
 * crypto/tls: fix generate_cert.go.
 * crypto/x509: prevent chain cycles in Verify.
 * csv: new package.
 * doc: remove ed from apt-get package list.
 * docs: fold the prog.sh scripting from makehtml into htmlgen itself.
 * ebnflint: better handling of stdin.
 * exp/regexp/syntax: new experimental RE2-based regexp implementation.
 * exp/template: a new experimental templating package.
 * fmt: add SkipSpace to fmt's ScanState interface.
 * fmt: rename errno and error to err for doc consistency.
 * gc: avoid package name ambiguity in error messages,
 	fix package quoting logic,
 	fixes for Plan 9 (thanks Lucio De Re).
 * go/build: evaluate symlinks before comparing path to GOPATH.
 * gob: use exported fields in structs in the package documentation.
 * godoc: ignore directories that begin with '.',
 	search GOPATH for documentation.
 * gofix: os/signal, path/filepath, and sort fixes (thanks Robert Hencke),
 * goinstall: add support for generic hosts (thanks Julian Phillips),
 	only report successfully-installed packages to the dashboard,
 	try to access via https (thanks Yasuhiro Matsumoto).
 * gotest: add -test.benchtime and -test.cpu flags.
 * html: fixes and improvements (thanks Yasuhiro Matsumoto).
 * http/cgi: add Handler.Dir to specify working directory (thanks Yasuhiro Matsumoto).
 * http: add StripPrefix handler wrapper,
 	assume ContentLength 0 on GET requests,
 	better handling of 0-length Request.Body,
 	do TLS handshake explicitly before copying TLS state,
 	document that ServerConn and ClientConn are low-level,
 	make NewChunkedReader public (thanks Andrew Balholm),
 	respect Handlers setting Connection: close in their response.
 * image: more tests, Paletted.Opaque optimization.
 * io.WriteString: if the object has a WriteString method, use it (thanks Evan Shaw).
 * ld: elide the Go symbol table when using -s (thanks Anthony Martin).
 * ld: fix ELF strip by removing overlap of sections (thanks Gustavo Niemeyer).
 * mime/multipart: parse LF-delimited messages, not just CRLF.
 * mime: permit lower-case media type parameters (thanks Pascal S. de Kloe).
 * misc/dashboard: new features and improvements (not yet deployed).
 * misc/emacs: update list of builtins (thanks Quan Yong Zhai).
 * misc/vim: allow only utf-8 for file encoding (thanks Yasuhiro Matsumoto).
 * os: fix documentation for FileInfo.Name,
 	simplify WriteString,
 	use a different symbol from syscall in mkunixsignals.sh.
 * path/filepath: enable TestWalk to run on windows (thanks Alex Brainman).
 * reflect: add MethodByName,
 	allow Len on String values.
 * regexp: document that Regexp is thread-safe.
 * runtime/cgo: check for errors from pthread_create (thanks Albert Strasheim).
 * runtime: add Semacquire/Semrelease benchmarks,
 	improved Semacquire/Semrelease implementation,
 	windows/amd64 port (thanks Wei Guangjing).
 * sync: add fast path to Once,
 	improve Mutex to allow successive acquisitions,
 	new and improved benchmarks.
 * syscall: regenerate zerrors for darwin/linux/freebsd,
 	support for tty options in StartProcess (thanks Ken Rockot).
 * testing: make ResetTimer not start/stop the timer,
 	scale benchmark precision to 0.01ns if needed.
 * time: zero-pad two-digit years.
 * unicode/maketables: update debugging data.
 * windows: define and use syscall.Handle (thanks Wei Guangjing).
 * xml: add Marshal and MarshalIndent.
 </pre>

 <h2 id="2011-06-23">2011-06-23</h2>

 <pre>
 This snapshot includes a language change that restricts the use of goto.
 In essence, a "goto" statement outside a block cannot jump to a label inside
 that block. Your code may require changes if it uses goto.
 This changeset shows how the new rule affected the Go tree:
 	http://code.google.com/p/go/source/detail?r=dc6d3cf9279d

 The os.ErrorString type has been hidden. If your code uses os.ErrorString it
 must be changed. Most uses of os.ErrorString can be replaced with os.NewError.

 Other changes:
 * 5c: do not use R9 and R10.
 * 8l: more fixes for Plan 9 (thanks Lucio De Re).
 * build: Make.ccmd: link with mach lib (thanks Joe Poirier).
 * build: exclude packages that fail on Plan 9 (thanks Anthony Martin).
 * cc: nit: silence comment warnings (thanks Dave Cheney).
 * codereview.py: note that hg change -d abandons a change list (thanks Robert Hencke).
 * crypto/openpgp: add ElGamal support.
 * doc/faq: add question about converting from []T to []interface{}.
 * doc: Effective Go: fix variadic function example (thanks Ben Lynn).
 * exec: LookPath should not search %PATH% for files like c:cmd.exe (thanks Alex Brainman),
         add support for Plan 9 (thanks Anthony Martin),
         better error message for windows LookPath (thanks Alex Brainman).
 * fmt: catch panics from calls to String etc.
 * gc: descriptive panic for nil pointer -&gt; value method call,
         implement goto restriction,
         unsafe.Alignof, unsafe.Offsetof, unsafe.Sizeof now return uintptr.
 * go/build: include Import objects in Script Inputs.
 * godefs: rudimentary tests (thanks Robert Hencke).
 * goinstall: refactor and generalize repo handling code (thanks Julian Phillips),
         temporarily use Makefiles by default (override with -make=false).
 * gopprof: update list of memory allocators.
 * http: add Server.ListenAndServeTLS,
         buffer request.Write,
         fix req.Cookie(name) with cookies in one header,
         permit handlers to explicitly remove the Date header,
         write Header keys with empty values.
 * image: basic test for the 16-bits-per-color-channel types.
 * io: clarify Read, ReadAt, Copy, Copyn EOF behavior.
 * ld: don't attempt to build dynamic sections unnecessarily (thanks Gustavo Niemeyer).
 * libmach: fix disassembly of FCMOVcc and FCOMI (thanks Anthony Martin),
         fix tracing on linux (for cov) (thanks Anthony Martin).
 * mime: fix RFC references (thanks Pascal S. de Kloe).
 * misc/gobuilder: run make single-threaded on windows (thanks Alex Brainman).
 * misc/godashboard: Accept sub-directories for goinstall's report (thanks Yasuhiro Matsumoto).
 * nacl, tiny: remove vestiges (thanks Robert Hencke).
 * net, syscall: interface for windows (thanks Yasuhiro Matsumoto).
 * os: change Waitmsg String method to use pointer receiver (thanks Graham Miller).
 * runtime: don't use twice the memory with grsec-like kernels (thanks Gustavo Niemeyer),
 * spec: disallow goto into blocks.
 * sync: restore GOMAXPROCS during benchmarks.
 * syscall: add LSF support for linux (thanks Mikio Hara),
         add socket control message support for darwin, freebsd, linux (thanks Mikio Hara),
         add tty support to StartProcess (thanks Ken Rockot),
         fix build for Sizeof change.
 * test: test of goto restrictions.
 * time: add support for Plan 9 (thanks Anthony Martin).
 </pre>

 <h2 id="2011-06-16">2011-06-16</h2>

 <pre>
 This snapshot includes changes to the sort and image/draw packages that will
 require changes to client code.

 The sort.IntArray type has been renamed to IntSlice, and similarly for
 StringArray and Float64Array.

 The image/draw package's Draw function now takes an additional argument,
 a compositing operator. If in doubt, use draw.Over.

 Other changes:
 * build: fix header files for Plan 9 (thanks Lucio De Re).
 * cgo: handle new Apple LLVM-based gcc from Xcode 4.2.
 * crypto/openpgp: add ability to encrypt and sign messages.
 * doc/gopher: add goggled gopher logo for App Engine.
 * doc: Update notes for 3-day Go course.
 * exec: make LookPath work when PATHEXT var not set on Windows (thanks Alex Brainman).
 * exp/regexp/syntax: syntax data structures, parser, escapes, character classes.
 * exp/template: lexical scanner for new template package.
 * fmt: debugging formats for characters: %+q %#U.
 * gc: frame compaction for arm,
         handle go print() and go println(),
         work around goto bug.
 * go/build: fixes, self-contained tests.
 * go/printer, gofmt: print "select {}" on one line.
 * godoc: replace OS file system accesses in favor of a FileSystem interface.
 * gofix: fix inconsistent indentation in help output (thanks Scott Lawrence).
 * goinstall: use go/build package to scan and build packages.
 * http/spdy: improve error handling (thanks William Chan).
 * http: use runtime/debug.Stack() to dump stack trace on panic.
 * ld: dwarf emit filenames in debug_line header instead of as extended opcodes,
         fix link Windows PE __declspec(dllimport) symbol (thanks Wei Guangjing),
         make .rodata section read-only (thanks Gustavo Niemeyer).
 * mail: decode RFC 2047 "B" encoding.
 * mime/multipart: remove temp files after tests on Windows (thanks Alex Brainman).
 * net: export all fields in Interface (thanks Mikio Hara),
         rearrange source to run more tests on Windows (thanks Alex Brainman),
         sendfile for win32 (thanks Yasuhiro Matsumoto).
 * os: Plan 9, fix OpenFile &amp; Chmod, add Process.Kill (thanks Yuval Pavel Zholkover).
 * runtime: fix Plan 9 "lingering goroutines bug" (thanks Yuval Pavel Zholkover).
 * spec: clarify rules for append, scope rules for :=,
         specify constant conversions,
         unsafe.Alignof/Offsetof/Sizeof return uintptr.
 * syscall, os, exec: add *syscall.SysProcAttr field to os.ProcAttr and exec.Cmd.
 * syscall: add ptrace on darwin (thanks Jeff Hodges),
         mksyscall_windows.pl should output unix newline (thanks Yasuhiro Matsumoto).
         update BPF support for BSD variants (thanks Mikio Hara),
         use strict in perl scripts (thanks Yasuhiro Matsumoto).
 * xml: handle non-string attribute fields (thanks Maxim Ushakov).
 </pre>

 <h2 id="2011-06-09">2011-06-09 (<a href="release.html#r58">base for r58</a>)</h2>

 <pre>
 This snapshot includes changes to the strconv, http, and exp/draw packages.
 Client code that uses the http or exp/draw packages will need to be changed,
 and code that uses strconv or fmt's "%q" formatting directive merits checking.

 The strconv package's Quote function now escapes only those Unicode code points
 not classified as printable by unicode.IsPrint. Previously Quote would escape
 all non-ASCII characters. This also affects the fmt package's "%q" formatting
 directive. The previous quoting behavior is still available via strconv's new
 QuoteToASCII function.

 Most instances of the type map[string][]string in the http package have been
 replaced with the new Values type. The http.Values type has the Get, Set, Add,
 and Del helper methods to make working with query parameters and form values
 more convenient.

 The exp/draw package has been split into the image/draw and exp/gui packages.

 Other changes:
 * 8l, ld: initial adjustments for Plan 9 native compilation of 8l (thanks Lucio De Re).
 * arm: floating point improvements (thanks Fan Hongjian).
 * big: Improved speed of nat-to-string conversion (thanks Michael T. Jones),
         Rat outputs the requested precision from FloatString (thanks Graham Miller),
         gobs for big.Rats.
 * cgo: support non intel gcc machine flags (thanks Dave Cheney).
 * compress/lzw: do not use background goroutines,
         reduce decoder buffer size from 3*4096 to 2*4096.
 * crypto/twofish: fix Reset index overflow bug.
 * crypto: reorg, cleanup and add function for generating CRLs.
 * exec: export the underlying *os.Process in Cmd.
 * gc: enable building under clang/2.9 (thanks Dave Cheney),
         preparatory work toward escape analysis, compact stack frames.
 * go/build: new incomplete package for building go programs.
 * godefs: do not assume forward type references are enums (thanks Robert Hencke).
 * gofix, gofmt: fix diff regression from exec change.
 * html: improve attribute parsing, note package status.
 * http: don't fail on accept hitting EMFILE,
         fix handling of 0-length HTTP requests.
 * image/draw: fix clipping bug where sp/mp were not shifted when r.Min was.
 * image/gif: fix buglet in graphics extension.
 * image/tiff: support for bit depths other than 8 (thanks Benny Siegert).
 * ld: fix and simplify ELF symbol generation (thanks Anthony Martin)
 * libmach: use the standardized format for designated initializers (thanks Jeff Hodges)
 * mail: address list parsing.
 * net: add network interface identification API (thanks Mikio Hara),
         fix bug in net.Interfaces: handle elastic sdl_data size correctly (thanks Mikio Hara).
 * netchan: added drain method to importer (thanks David Jakob Fritz).
 * os: add Process.Kill and Process.Signal (thanks Evan Shaw),
         fix Getenv for Plan 9 (thanks Yuval Pavel Zholkover).
 * runtime: improve memmove by checking memory overlap (thanks Quan Yong Zhai),
         support for Linux grsecurity systems (thanks Jonathan Mark).
 * spec: handle a corner case for shifts.
 * testing: check that tests and benchmarks do not affect GOMAXPROCS (thanks Dmitriy Vyukov).
 * unicode: add IsPrint and related properties, general categories.
 </pre>

 <h2 id="2011-06-02">2011-06-02</h2>

 <pre>
 This snapshot includes changes to the exec package that will require changes
 to client code.

 The exec package has been re-designed with a more convenient and succinct API.
 This code:
 	args := []string{"diff", "-u", "file1.txt", "file2.txt"}
 	p, err := exec.Run("/usr/bin/diff", args, os.Environ(), "",
 		exec.DevNull, exec.Pipe, exec.DevNull)
 	if err != nil {
 		return nil, err
 	}
 	var buf bytes.Buffer
 	io.Copy(&amp;buf, p.Stdout)
 	w, err := p.Wait(0)
 	p.Close()
 	if err != nil {
 		return nil, err
 	}
 	return buf.Bytes(), err
 can be rewritten as:
 	return exec.Command("diff", "-u", "file1.txt", "file2.txt").Output()
 See the exec package documentation for the details ("godoc exec").

 By setting the GOPATH environment variable you can use goinstall to build and
 install your own code and external libraries outside of the Go tree (and avoid
 writing Makefiles).
 See the goinstall command documentation for the details ("godoc goinstall").

 Other changes:
 * 5g: alignment fixes.
 * 6l, 8l: fix Mach-O binaries with many dynamic libraries.
 * 8l: emit resources (.rsrc) in Windows PE.  (thanks Wei Guangjing).
 * asn1: fix marshalling of empty optional RawValues (thanks Mikkel Krautz).
 * big: make Int and Rat implement fmt.Scanner (thanks Evan Shaw),
 	~8x faster number scanning,
 	remove some unnecessary conversions.
 * cgo: restrict #cgo directives to prevent shell expansion (thanks Gustavo Niemeyer),
 	support pkg-config for flags and libs (thanks Gustavo Niemeyer).
 * compress/flate: fix Huffman tree bug,
 	do not use background goroutines.
 * crypto/openpgp: add support for symmetrically encrypting files.
 * crypto/tls/generate_cert.go: fix misspelling of O_CREATE.
 * dashboard: send notification emails when the build breaks.
 * doc: mention go/printer instead of container/vector in effective go,
 	put Release History link on 'Documentation' page,
 	put Weekly Snapshot History link on 'Contributing' page.
 * encoding/base64: add DecodeString and EncodeToString.
 * encoding/binary: add a non-reflect fast path for Read,
 	add a non-reflect fast path for Write.
 * encoding/hex: add hex dumping.
 * encoding/line: delete package. Its functionality is now in bufio.
 * filepath: Abs must always return a clean path (thanks Gustavo Niemeyer).
 * fmt: fix bug in UnreadRune,
 	make %q work for integers, printing a quoted character literal,
 	return EOF when out of input in Scan*.
 * gc: check parameter declarations in interface fields (thanks Anthony Martin),
 	disallow ... in type conversions (thanks Anthony Martin),
 	do not force heap allocation on referencing outer variable in a closure,
 	fix m[x], _ = y.(T),
 	implement new shift rules,
 	patch y.tab.c to fix build when using Bison 2.5,
 	relax assignability of method receivers (thanks Anthony Martin),
 	typecheck the whole tree before walking.
 * go/scanner: don't allow "0x" and "0X" as integers (thanks Evan Shaw).
 * gobuilder: fixes for windows (thanks Alex Brainman).
 * godoc: basic setup for running godoc on local app engine emulator,
 	display advert for the package dashboard on package list page.
 * goinstall: fixes for windows (thanks Alex Brainman),
 	more verbose logging with -v.
 * gotest, pkg/exec: use bash to run shell scripts on windows (thanks Alex Brainman).
 * http/spdy: redo interfaces, flesh out implementation &amp; frame types (thanks William Chan).
 * http: Transport hook to register non-http(s) protocols,
 	add client+server benchmark,
 	catch Handler goroutine panics,
 	fix Set-Cookie date parsing,
 	have client set Content-Length when possible,
 	let Transport use a custom net.Dial function,
 	propagate Set-Cookie in reverse proxy,
 	ServeFile shouldn't send Content-Length when Content-Encoding is set.
 * image: add a SubImage method.
 * image/gif: simplify blockReader.Read.
 * image/png: fix encoding of images that don't start at (0, 0).
 * io, net, http: sendfile support.
 * io: add ByteScanner, RuneScanner interfaces.
 * ld: add -w to disable dwarf, make errors obviously from dwarf.
 * mail: new package.
 * mime/multipart: misc code/doc fixes.
 * misc/cgo: remove reference to 'destroy' function.
 * misc/emacs: don't select the mark after gofmt (thanks Eric Eisner).
 * misc/gophertool: Chrome extension to aid in Go development
 * misc/vim: limit Fmt command to Go buffers (thanks Yasuhiro Matsumoto).
 * net: if we stop polling, remove any pending events for the socket,
 	update IP multicast socket options (thanks Mikio Hara).
 * os: Fix test to work on Solaris,
 	fix Readdir(0) on EOF,
 	fix Readdir, Readdirnames (thanks Yuval Pavel Zholkover),
 	fix os.MkdirAll with backslash path separator (thanks Yasuhiro Matsumoto),
 	handle OpenFile flag parameter properly on Windows (thanks Alex Brainman).
 * path/filepath: remove string constants.
 * pkg: spelling tweaks, I-Z (thanks Robert Hencke).
 * quietgcc: fix typo, respect $TMPDIR.
 * runtime: do not garbage collect windows callbacks (thanks Alex Brainman),
 	fix mmap error return on linux (thanks Dmitry Chestnykh),
 	reset GOMAXPROCS during tests,
 	save cdecl registers in Windows SEH handler (thanks Alexey Borzenkov).
 * spec: be precise with the use of the informal ellipsis and the Go token,
 	clarify rules for shifts.
 * strconv: add QuoteRune; analogous to Quote but for runes rather than strings.
 * strings: implement UnreadByte, UnreadRune.
 * sync: always wake up sleeping goroutines on Cond.Signal (thanks Gustavo Niemeyer).
 * sync/atomic: fix check64.
 * syscall: add ProcAttr field to pass an unescaped command line on windows (thanks Vincent Vanackere),
 	add routing messages support for Linux and BSD (thanks Mikio Hara).
 * template: fixes and clean-ups (thanks Gustavo Niemeyer).
 * time: fix Format bug: midnight/noon are 12AM/PM not 0AM/PM.
 * unicode: make the tables smaller.
 </pre>

 <h2 id="2011-05-22">2011-05-22</h2>

 <pre>
 This snapshot includes changes to the http package that will require changes to
 client code.

 The finalURL return value of the Client.Get method has been removed.
 This value is now accessible via the new Request field on http.Response.
 For example, this code:

 	res, finalURL, err := http.Get(...)

 should be rewritten as:

 	res, err := http.Get(...)
 	if err != nil {
 		// ...
 	}
 	finalURL := res.Request.URL.String()

 Uses of http.Get that assign the finalURL value to _ can be rewritten
 automatically with gofix.

 This snapshot also includes an optimization to the append function that makes it
 between 2 and 5 times faster in typical use cases.

 Other changes:
 * 5a, 6a, 8a, cc: remove old environment variables.
 * 5c, 5g: fix build with too-smart gcc.
 * 5l, 8l: add ELF symbol table to binary.
 * 5l: delete pre-ARMv4 instruction implementations, other fixes.
 * 6l, 8l: emit windows dwarf sections like other platforms (thanks Alex Brainman).
 * 6l: fix emit windows dwarf sections (thanks Wei Guangjing).
 * 8g: fix conversion from float to uint64 (thanks Anthony Martin).
 * Make.cmd: create TARGDIR if necessary (thanks Gustavo Niemeyer).
 * asn1: add big support.
 * big: add Int methods to act on numbered bits (thanks Roger Peppe),
 	better support for string conversions,
 	support %v and # modifier, better handling of unknown formats.
 * cgi: export RequestFromMap (thanks Evan Shaw),
 	set Request.TLS and Request.RemoteAddr for children.
 * cgo: use packed struct to fix Windows behavior.
 * codereview: add release branch support,
 	fetch metadata using JSON API, not XML scraping,
 	handle 'null as missing field' in rietveld json.
 * compress/lzw: silently drop implied codes that are too large.
 * compress/zlib: actually use provided dictionary in NewWriterDict
 * crypto/openpgp: add key generation support,
 	change PublicKey.Serialize to include the header.
 * crypto/rand: add utility functions for number generation (thanks Anthony Martin).
 * crypto/tls: export the verified chains.
 * crypto/x509/crl: add package.
 * crypto/x509: export raw SubjectPublicKeyInfo,
 	support DSA public keys in X.509 certs,
 	support parsing and verifying DSA signatures (thanks Jonathan Allie).
 * doc/roadmap: put "App Engine support" under "Done".
 * doc: add I/O 2011 talks to talks/, docs.html, and front page.
 * effective go: explain about values/pointers in String() example,
 	update to new Open signature.
 * exp/draw: fast paths for drawing a YCbCr or an NRGBA onto an RGBA.
 * filepath: make EvalSymlinks work on Windows (thanks Alex Brainman).
 * flag: allow distinct sets of flags.
 * gc: fix type switch error message for invalid cases (thanks Lorenzo Stoakes),
 	fix unsafe.Sizeof,
 	preserve original expression for errors.
 * go/ast, go/doc, godoc: consider struct fields and interface methods when filtering ASTs.
 * go/ast: consider anonymous fields and set Incomplete bit when filtering ASTs,
 	properly maintain map of package global imports.
 * go/doc, godoc: when filtering for godoc, don't remove elements of a declaration.
 * go/parser: accept parenthesized receive operations in select statements,
 	always introduce an ast.Object when declaring an identifier.
 * go/printer, gofmt: fix alignment of "=" in const/var declarations,
 	fix formatting of expression lists (missing blank).
 * go/printer: added simple performance benchmark,
 	make tests follow syntactic restrictions,
 	more accurate comment for incomplete structs/interfaces,
 * go/token: faster FileSet.Position implementation.
 * go/types: type checker API + testing infrastructure.
 * godoc: added -index flag to enable/disable search index,
 	if there is no search box, don't run the respective JS code.
 * gofmt: update test.sh (exclude a file w/ incorrect syntax).
 * html: parse empty, unquoted, and single-quoted attribute values.
 * http/cgi: correctly set request Content-Type (thanks Evan Shaw),
 	pass down environment variables for IRIX and Solaris.
 * http/pprof: fix POST reading bug.
 * http/spdy: new incomplete package (thanks Ross Light).
 * http: Client.Do should follow redirects for GET and HEAD,
 	add Header.Write method (thanks Evan Shaw),
 	add Request.SetBasicAuth method,
 	add Transport.ProxySelector,
 	add http.SetCookie(ResponseWriter, *Cookie),
 	don't Clean query string in relative redirects,
 	fix FormFile nil pointer dereference on missing multipart form,
 	fix racy test with a simpler version,
 	fix two Transport gzip+persist crashes,
 	include Host header in requests,
 	make HEAD client request follow redirects (thanks Eivind Uggedal).
 	update cookie doc to reference new RFC 6265,
 	write cookies according to RFC 6265 (thanks Christian Himpel).
 * image/bmp: implement a BMP decoder.
 * image/gif: new package provides a GIF decoder.
 * image/jpeg: decode grayscale images, not just color images.
 	optimizations and tweaks.
 * image/png: encode paletted images with alpha channel (thanks Dmitry Chestnykh),
 	speed up opaque RGBA encoding.
 * image/tiff: implement a decoder (thanks Benny Siegert).
 * image: add type-specific Set methods and use them when decoding PNG,
 	make AlphaColor.Set conform to usual signature (thanks Roger Peppe),
 	png &amp; jpeg encoding benchmarks.
 * ld: do not emit reference to dynamic library named "",
 	fix alignment of rodata section on Plan 9 (thanks Anthony Martin),
 	make ELF binaries with no shared library dependencies static binaries.
 * make.bash: remove old bash version of gotest on Windows (thanks Alex Brainman).
 * make: add nuke target for C commands and libs (thanks Anthony Martin).
 * mime/multipart: add FileName accessor on Part,
 	add Writer,
 	return an error on Reader EOF, not (nil, nil).
 * misc/cgo/test: run tests.
 * misc/emacs: use UTF-8 when invoking gofmt as a subprocess (thanks Sameer Ajmani).
 * misc/vim: new Vim indentation script.
 * net, http: add and make use of IP address scope identification API (thanks Mikio Hara).
 * net: default to 127.0.0.1, not localhost, in TestICMP,
 	don't crash on unexpected DNS SRV responses,
 	enable SO_REUSEPORT on BSD variants (thanks Mikio Hara),
 	protocol family adaptive address family selection (thanks Mikio Hara),
 	re-enable wildcard listening (thanks Mikio Hara),
 	sort records returned by LookupSRV (thanks Gary Burd).
 * os: make Readdir &amp; Readdirnames return os.EOF at end,
 	make Setenv update C environment variables.
 * reflect: allow unexported key in Value.MapIndex.
 * runtime, sync/atomic: fix arm cas.
 * runtime: add newline to "finalizer already set" error (thanks Albert Strasheim),
 	handle out-of-threads on Linux gracefully (thanks Albert Strasheim),
 	fix function args not checked warning on ARM (thanks Dave Cheney),
 	make StackSystem part of StackGuard (thanks Alexey Borzenkov),
 	maybe fix Windows build broken by cgo setenv CL.
 * spec: clarify semantics of integer division,
 	clarify semantics of range clause,
 	fix error in production syntax,
 	narrow syntax for expression and select statements,
 	newlines cannot be used inside a char or "" string literal,
 	restricted expressions may still be parenthesized.
 * strings: make Reader.Read use copy instead of an explicit loop.
 * syscall: add Windows file mapping functions and constants (thanks Evan Shaw),
 	add IPv6 scope zone ID support (thanks Mikio Hara),
 	add netlink support for linux/386, linux/amd64, linux/arm (thanks Mikio Hara),
 	add Sendfile,
 	adjust freebsd syscalls.master URL properly (thanks Mikio Hara),
 	change Overlapped.HEvent type, it is a handle (thanks Alex Brainman).
 * syslog: fix skipping of net tests (thanks Gustavo Niemeyer).
 * template: support string, int and float literals (thanks Gustavo Niemeyer).
 * xml: fix reflect error.
 </pre>

 <h2 id="2011-04-27">2011-04-27 (<a href="release.html#r57">base for r57</a>)</h2>

 <pre>
 This snapshot includes revisions to the reflect package to make it more
 efficient, after the last weekly's major API update. If your code uses reflect
 it may require further changes, not all of which can be made automatically by
 gofix. For the full details of the change, see
 	http://codereview.appspot.com/4435042
 Also, the Typeof and NewValue functions have been renamed to TypeOf and ValueOf.

 Other changes:
 * 5c: make alignment rules match 5g, just like 6c matches 6g.
 * 8g, 8l: fix "set but not used" gcc error (thanks Fazlul Shahriar).
 * all-qemu.bash: remove DISABLE_NET_TESTS.
 * build: remove DISABLE_NET_TESTS.
 * builder: build multiple targets in parallel.
 * cgo: avoid "incompatible pointer type" warning (thanks Albert Strasheim).
 * codereview: add 'hg undo' command, various other fixes.
 * compress/flate: dictionary support.
 * compress/zlib: add FDICT flag in Reader/Writer (thanks Ross Light).
 * container/heap: fix circular dependency in test.
 * crypto/openpgp: better handling of keyrings.
 * crypto/rsa: support > 3 primes.
 * crypto/tls: add server-side OCSP stapling support.
 * crypto/x509: memorize chain building.
 * crypto: move certificate verification into x509.
 * dashboard: build most recent revision first.
 * doc: mention make version in install.html.
 * expvar: add Func for functions that return values that are JSON marshalable.
 * fmt: decrease recursion depth in tests to permit them to run under gccgo,
 	tweak the doc for %U.
 * gc: allow complex types to be receiver types (thanks Robert Hencke),
 	correct handling of unexported method names in embedded interfaces,
 	explain why invalid receiver types are invalid,
 	fix copy([]int, string) error message (thanks Quan Yong Zhai),
 	fix 'invalid recursive type' error (thanks Lorenzo Stoakes),
 	many bug fixes.
 * go spec: attempt at clarifying language for "append",
 	for map types, mention indexing operations.
 * go/types: update for export data format change.
 * gob: fix handling of indirect receivers for GobDecoders,
 	fix trivial bug in map marshaling,
 	have errorf always prefix the message with "gob: ",
 	test case for indirection to large field,
 	use new Implements and AssignableTo methods in reflect,
 	when decoding a string, allocate a string, not a []byte.
 * gobuilder: permit builders of the form goos-goarch-foo,
 	respect MAKEFLAGS if provided (thanks Dave Cheney).
 * godoc: use "search" input type for search box (thanks Dmitry Chestnykh).
 * gofix: add support for reflect rename.
 * gofmt: add -d (diff) (thanks David Crawshaw),
 	don't crash when rewriting nil interfaces in AST,
 	exclude test case that doesn't compile w/o errors,
 	gofmt test harness bug fix.
 * goinstall: support GOPATH; building and installing outside the Go tree,
 	support building executable commands.
 * gopack: fix prefix bug,
 	preserve safe flag when not adding unsafe objects to archive.
 * gotest: add timing, respect $GOARCH,
 	generate gofmt-compliant code.
 * http/cgi: copy some PATH environment variables to child,
 	improve Location response handling,
 	pass some default environment variables.
 * http/fcgi: new package (thanks Evan Shaw).
 * http: add NewRequest helper,
 	add MultipartForm, ParseMultipartForm, and FormFile to Request,
 	be clear when failing to connect to a proxy,
 	bug fixes and new tests,
 	consume request bodies before replying,
 	don't quote Set-Cookie Domain and Path (thanks Petar Maymounkov),
 	fix IP confusion in TestServerTimeouts,
 	handler timeout support,
 	ServerConn, ClientConn: add real Close (thanks Petar Maymounkov),
 	make Client redirect policy configurable,
 	put a limit on POST size,
 	reverse proxy handler.
 * image/jpeg: add an encoder,
 	decode to a YCbCr image instead of an RGBA image.
 * ioutil: add Discard.
 * json: keep track of error offset in SyntaxError.
 * ld: defend against some broken object files,
 	do not emit empty dwarf pe sections (thanks Alex Brainman),
 	fix 6l -d on Mac, diagnose invalid use of -d,
 	fix Plan 9 symbol table (thanks Anthony Martin),
 	remove MachoLoad limit.
 * make: prevent rm provoking 'text file busy' errors (thanks Lorenzo Stoakes).
 * mime/multipart: add ReadForm for parsing multipart forms,
 	limit line length to prevent abuse.
 * mime: RFC 2231 continuation / non-ASCII support,
 	bunch more tests, few minor parsing fixes.
 * misc/goplay: fix Tab and Shift+Enter in Firefox (thanks Dmitry Chestnykh).
 * net: disable one more external network test,
 	fix EAI_BADFLAGS error on freebsd (thanks Mikio Hara),
 	fix ParseIP (thanks Quan Yong Zhai),
 	fix dialgoogle_test.go (thanks Quan Yong Zhai),
 	try /etc/hosts before loading DNS config (thanks Dmitry Chestnykh),
 	use C library resolver on FreeBSD, Linux, OS X / amd64, 386.
 * os/user: new package to look up users.
 * os: Open with O_APPEND|O_CREATE to append on Windows (thanks Alex Brainman),
 	fix race in ReadAt/WriteAt on Windows (thanks Alex Brainman),
 	turn EPIPE exit into panic.
 * rc/env.bash: fix to build on windows under msys (thanks Joe Poirier).
 * reflect: allow Slice of arrays,
 	fix Copy of arrays (thanks Gustavo Niemeyer),
 	require package qualifiers to match during interface check,
 	add Type.Implements, Type.AssignableTo, Value.CallSlice,
 	make Set match Go.
 * rpc: allow the first argument of a method to be a value rather than a pointer,
 	run benchmarks over HTTP as well as direct network connections.
 * run.bash: remove redundant rebuilds.
 * runtime/plan9: warning remediation for Plan 9 (thanks Lucio De Re),
 * runtime: many bug fixes,
 	fix GOMAXPROCS vs garbage collection bug (thanks Dmitriy Vyukov),
 	fix mkversion to output valid path separators (thanks Peter Mundy),
 	more graceful out-of-memory crash,
 	require package qualifiers to match during interface check,
 	skip functions with no lines when building src line table,
 	turn "too many EPIPE" into real SIGPIPE.
 * src/pkg: make package doc comments consistently start with "Package foo".
 * syscall: Madvise and Mprotect for Linux (thanks Albert Strasheim),
 	Mlock, Munlock, Mlockall, Munlockall on Linux (thanks Albert Strasheim),
 	add BPF support for darwin/386, darwin/amd64 (thanks Mikio Hara),
 	correct Windows CreateProcess input parameters (thanks Alex Brainman),
 	fix Ftruncate under linux/arm5 (thanks Dave Cheney),
 	permit StartProcess to hide the executed program on windows (thanks Vincent Vanackere).
 * test/bench: update timings; moving to new machine.
 * time: support Irix 6 location for zoneinfo files.
 * tutorial: modernize the definition and use of Open,
 	replace the forever loops with finite counts in sieve programs.
 * websocket: include *http.Request in websocket.Conn.
 * xml: Parser hook for non-UTF-8 charset converters.
 </pre>

 <h2 id="2011-04-13">2011-04-13</h2>

 <pre>
 weekly.2011-04-13

 This weekly snapshot includes major changes to the reflect package and the
 os.Open function.  Code that uses reflect or os.Open will require updating,
 which can be done mechanically using the gofix tool.

 The reflect package's Type and Value types have changed.  Type is now an
 interface that implements all the possible type methods.  Instead of a type
 switch on a reflect.Type t, switch on t.Kind().  Value is now a struct value
 that implements all the possible value methods.  Instead of a type switch on a
 reflect.Value v, switch on v.Kind().  See the change for the full details:
         http://code.google.com/p/go/source/detail?r=843855f3c026

 The os package's Open function has been replaced by three functions:
         OpenFile(name, flag, perm) // same as old Open
         Open(name) // same as old Open(name, O_RDONLY, 0)
         Create(name) // same as old Open(name, O_RDWR|O_TRUNC|O_CREAT, 0666)

 To update your code to use the new APIs, run "gofix path/to/code".  Gofix can't
 handle all situations perfectly, so read and test the changes it makes before
 committing them.

 Other changes:
 * archive/zip: add func OpenReader, type ReadCloser (thanks Dmitry Chestnykh).
 * asn1: Implement correct marshaling of length octets (thanks Luit van Drongelen).
 * big: don't crash when printing nil ints.
 * bufio: add ReadLine, to replace encoding/line.
 * build: make the build faster, quieter.
 * codereview: automatically port old diffs forward,
         drop Author: line on self-clpatch,
         recognize code URL without trailing slash.
 * crypto/block: remove deprecated package.
 * crypto/des: new package implementating DES and TDEA (thanks Yasuhiro Matsumoto).
 * crypto/ecdsa, crypto/rsa: use io.ReadFull to read from random source (thanks Dmitry Chestnykh).
 * crypto/rsa: add 3-prime support,
         add support for precomputing CRT values,
         flip the CRT code over so that it matches PKCS#1.
 * crypto/x509: expose complete DER data (thanks Mikkel Krautz).
 * doc: new "Functions" codewalk (thanks John DeNero).
 * doc/roadmap: add sections on tools, packages.
 * fmt: allow %U for unsigned integers.
 * gc: fixes and optimizations.
 * go/printer, gofmt: use blank to separate import rename from import path.
 * go/scanner: better TokenString output.
 * go/types: new Go type hierarchy implementation for AST.
 * godashboard: show packages at launchpad.net (thanks Gustavo Niemeyer).
 * gofix: add -diff, various fixes and helpers.
 * gotest: fix a bug in error handling,
         fixes for [^.]_test file pattern (thanks Peter Mundy),
         handle \r\n returned by gomake on Windows (thanks Alex Brainman).
 * gotype: use go/types GcImporter.
 * govet: make name-matching for printf etc. case-insensitive.
 * http: allow override of Content-Type for ServeFile,
         client gzip support,
         do not listen on 0.0.0.0 during test,
         flesh out server Expect handling + tests.
 * image/ycbcr: new package.
 * image: allow "?" wildcards when registering image formats.
 * io: fixes for Read with n > 0, os.EOF (thanks Robert Hencke).
 * ld: correct Plan 9 compiler warnings (thanks Lucio De Re),
         ELF header function declarations (thanks Lucio De Re),
         fix Mach-O X86_64_RELOC_SIGNED relocations (thanks Mikkel Krautz),
         fix Mach-O bss bug (thanks Mikkel Krautz),
         fix dwarf decoding of strings for struct's fieldnames (thanks Luuk van Dijk),
         fixes and optimizations (25% faster).
 * log: generalize getting and setting flags and prefix.
 * misc/cgo/life: enable build and test on Windows (thanks Alex Brainman).
 * misc/vim: add plugin with Fmt command (thanks Dmitry Chestnykh),
         update type highlighting for new reflect package.
 * net: disable multicast tests by default (thanks Dave Cheney),
         sort records returned by LookupMX (thanks Corey Thomasson).
 * openpgp: Fix improper := shadowing (thanks Gustavo Niemeyer).
 * os: rename Open to OpenFile, add new Open, Create,
         fix Readdir in Plan 9 (thanks Fazlul Shahriar).
 * os/inotify: use _test for test files, not _obj.
 * pkg/path: enable tests on Windows (thanks Alex Brainman).
 * reflect: new Type and Value API.
 * src/pkg/Makefile: trim per-directory make output except on failure.
 * syscall: Add DT_* and MADV_* constants on Linux (thanks Albert Strasheim),
         add Mmap, Munmap on Linux, FreeBSD, OS X,
         fix StartProcess in Plan 9 (thanks Fazlul Shahriar),
         fix Windows Signaled (thanks Alex Brainman).
 * test/bench: enable build and test on Windows (thanks Alex Brainman).
 </pre>

 <h2 id="2011-04-04">2011-04-04</h2>

 <pre>
 This snapshot includes changes to the net package. Your code will require
 changes if it uses the Dial or LookupHost functions.

 The laddr argument has been removed from net.Dial, and the cname return value
 has been removed from net.LookupHost. The new net.LookupCNAME function can be
 used  to find the canonical host for a given name.  You can update your
 networking code with gofix.

 The gotest shell script has been replaced by a Go program, making testing
 significantly faster.

 Other changes:
 * asn1: extensions needed for parsing Kerberos.
 * bufio: Write and WriteString cleanup (thanks Evan Shaw).
 * bytes, strings: simplify Join (thanks Evan Shaw).
 * crypto/cipher: bad CTR IV length now triggers panic.
 * crypto/tls: extend NPN support to the client,
 	added X509KeyPair function to parse a Certificate from memory.
 * crypto/x509: parse Extended Key Usage extension (thanks Mikkel Krautz).
 * debug/gosym: remove need for gotest to run preparatory commands.
 * fmt: implement precision (length of input) values for %q: %.20q.
 * go/parser: fix scoping for local type declarations (thanks Roger Peppe),
 	package name must not be the blank identifier.
 * go/printer, gofmt: remove special case for multi-line raw strings.
 * gopack: add P flag to remove prefix from filename information.
 * gotest: add -test.timeout option,
 	replace the shell script with the compiled program written in go,
 	execute gomake properly on Windows (thanks Alex Brainman).
 * gotry: move into its own directory, separate from gotest.
 * gotype: support for more tests, added one new test.
 * http: add Transport.MaxIdleConnsPerHost,
 	use upper case hex in URL escaping (thanks Matt Jones).
 * httptest: add NewTLSServer.
 * misc/kate: reorganize, remove closed() (thanks Evan Shaw).
 * misc/notepadplus: support for notepad++ (thanks Anthony Starks).
 * net: implement non-blocking connect (thanks Alexey Borzenkov).
 * os: fix MkdirAll("/thisdoesnotexist") (thanks Albert Strasheim),
 	Plan 9 support (thanks Yuval Pavel Zholkover),
 	add a few missing Plan 9 errors (thanks Andrey Mirtchovski),
 	fix FileInfo.Name returned by Stat (thanks David Forsythe).
 * path/filepath.Glob: add an error return,
 	don't drop known matches on error.
 * path/filepath: add support for Plan 9 (thanks Andrey Mirtchovski).
 * scanner: treat line comments like in Go.
 * syscall: Plan 9 support (thanks Yuval Pavel Zholkover),
 	StartProcess Chroot and Credential (thanks Albert Strasheim),
 	add BPF support for freebsd/386, freebsd/amd64 (thanks Mikio Hara),
 	make [Raw]Syscall6 pass 6th arg on linux/386 (thanks Evan Shaw).
 </pre>

 <h2 id="2011-03-28">2011-03-28</h2>

 <pre>
 This weekly release includes improved support for testing.

 Memory and CPU profiling is now available via the gotest tool. Gotest will
 produce memory and CPU profiling data when invoked with the -test.memprofile
 and -test.cpuprofile flags. Run "godoc gotest" for details.

 We have also introduced a way for tests to run quickly when an exhaustive test
 is unnecessary. Gotest's new -test.short flag in combination with the testing
 package's new Short function allows you to write tests that can be run in
 normal or "short" mode; short mode is now used by all.bash to reduce
 installation time.
 The Makefiles know about the flag - you can just run "make testshort".

 Other changes:
 * .hgignore: Ignore all goinstalled packages (thanks Evan Shaw).
 * build: add all-qemu.bash, handful of arm fixes,
         add support for SWIG, and add two SWIG examples,
         diagnose Ubuntu's buggy copy of gold,
         handle broken awk in version.bash (thanks Dave Cheney),
         reenable clean.bash without gomake (thanks Gustavo Niemeyer).
 * cgo: fix index-out-of-bounds bug.
 * codereview: permit CLs of the form weekly.DATE
 * crypto/ecdsa: truncate hash values.
 * crypto/openpgp: add DSA signature support.
 * dashboard: remove old python/bash builder, update README.
 * doc: explain release and weekly tags in install.html.
 * exec: document dir option for Run (thanks Gustavo Niemeyer).
 * flag: document Nflag function (thanks Fazlul Shahriar).
 * gc: remove interim ... error which rejects valid code.
 * go/ast: implemented NewPackage,
         merge CaseClause and TypeCaseClause.
 * go/parser: fix memory leak by making a copy of token literals,
         resolve identifiers properly.
 * go/printer, gofmt: avoid exponential layout algorithm,
         gofmt: simplify struct formatting and respect line breaks.
 * go/scanner: to interpret line comments with Windows filenames (thanks Alex Brainman).
 * go/token: use array instead of map for token-&gt;string table.
 * gob: optimizations to reduce allocations,
         use pointers in bootstrapType so interfaces behave properly.
 * gobuilder: recognize CLs of the form weekly.DATE.
 * godefs: handle volatile.
 * godoc: add -template flag to specify custom templates,
         fix path problem for windows (thanks Yasuhiro Matsumoto).
 * gofix: httpserver - rewrite rw.SetHeader to rw.Header.Set.
 * gofmt: add profiling flag.
 * gopprof: fix bug: do not rotate 180 degrees for large scrolls,
         update list of memory allocation functions.
 * gotest: fix gofmt issue in generated _testmain.go.
 * http: add NewProxyClientConn,
         avoid crash when asked for multiple file ranges,
         don't chunk 304 responses,
         export Transport, add keep-alive support.
 * ld: return > 0 exit code on unsafe import.
 * misc/bbedit: remove closed keyword (thanks Anthony Starks).
 * misc/emacs: gofmt: don't clobber the current buffer on failure.
 * misc/vim: remove 'closed' as a builtin function.
 * net: add FileConn, FilePacketConn, FileListener (thanks Albert Strasheim),
         don't force epoll/kqueue to wake up in order to add new events,
         let OS-specific AddFD routine wake up polling thread,
         use preallocated buffer for epoll and kqueue/kevent.
 * path/filepath: add EvalSymlinks function,
         fix TestEvalSymlinks when run under symlinked GOROOT.
 * path: work for windows (thanks Yasuhiro Matsumoto).
 * rpc: increase server_test timeout (thanks Gustavo Niemeyer),
         optimizations to reduce allocations.
 * runtime: fix darwin/amd64 thread VM footprint (thanks Alexey Borzenkov),
         fix gdb support for goroutines,
         more stack split fixes,
         os-specific types and code for setitimer,
         update defs.h for freebsd-386 (thanks Devon H. O'Dell).
 * strings: Map: avoid allocation when string is unchanged.
 * syscall: GetsockoptInt (thanks Albert Strasheim),
         StartProcess fixes for windows (thanks Alex Brainman),
         permit non-blocking syscalls,
         rename from .sh to .pl, because these files are in Perl.
 * test: enable tests using v, ok := &lt;-ch syntax (thanks Robert Hencke).
 * time: give a helpful message when we can't set the time zone for testing.
         isolate syscall reference in sys.go.
 </pre>

 <h2 id="2011-03-15">2011-03-15</h2>

 <pre>
 This week's release introduces a new release tagging scheme. We intend to
 continue with our weekly releases, but have renamed the existing tags from
 "release" to "weekly". The "release" tag will now be applied to one hand-picked
 stable release each month or two.

 The revision formerly tagged "release.2011-03-07.1" (now "weekly.2011-03-07.1")
 has been nominated our first stable release, and has been given the tag
 "release.r56". As we tag each stable release we will post an announcement to
 the new golang-announce mailing list:
   http://groups.google.com/group/golang-announce

 You can continue to keep your Go installation updated using "hg update
 release", but now you should only need to update once we tag a new stable
 release, which we will announce here. If you wish to stay at the leading edge,
 you should switch to the weekly tag with "hg update weekly".


 This weekly release includes significant changes to the language spec and the
 http, os, and syscall packages. Your code may need to be changed. It also
 introduces the new gofix tool.

 The closed function has been removed from the language. The syntax for channel
 receives has been changed to return an optional second value, a boolean value
 indicating whether the channel is closed. This code:
 	v := &lt;-ch
 	if closed(ch) {
 		// channel is closed
 	}
 should now be written as:
 	v, ok := &lt;-ch
 	if !ok {
 		// channel is closed
 	}

 It is now illegal to declare unused labels, just as it is illegal to declare
 unused local variables.

 The new gofix tool finds Go programs that use old APIs and rewrites them to use
 newer ones.  After you update to a new Go release, gofix helps make the
 necessary changes to your programs. Gofix will handle the http, os, and syscall
 package changes described below, and we will update the program to keep up with
 future changes to the libraries.

 The Hijack and Flush methods have been removed from the http.ResponseWriter
 interface and are accessible via the new http.Hijacker and http.Flusher
 interfaces. The RemoteAddr and UsingTLS methods have been moved from
 http.ResponseWriter to http.Request.

 The http.ResponseWriter interface's SetHeader method has been replaced by a
 Header() method that returns the response's http.Header. Caller code needs to
 change. This code:
 	rw.SetHeader("Content-Type", "text/plain")
 should now be written as:
 	rw.Header().Set("Content-Type", "text/plain")
 The os and syscall packages' StartProcess functions now take their final three
 arguments as an *os.ProcAttr and *syscall.ProcAttr values, respectively. This
 code:
 	os.StartProcess(bin, args, env, dir, fds)
 should now be written as:
 	os.StartProcess(bin, args, &amp;os.ProcAttr{Files: fds, Dir: dir, Env: env})

 The gob package will now encode and decode values of types that implement the
 gob.GobEncoder and gob.GobDecoder interfaces. This allows types with unexported
 fields to transmit self-consistent descriptions; one instance is big.Int and
 big.Rat.

 Other changes:
 * 5l, 6l, 8l: reduce binary size about 40% by omitting symbols for type, string, go.string.
 * 5l, 8l: output missing section symbols (thanks Anthony Martin).
 * 6l, 8l: fix gdb crash.
 * Make.cmd: also clean _test* (thanks Gustavo Niemeyer).
 * big: implemented custom Gob(En/De)coder for Int type.
 * build: remove duplicate dependency in Make.cmd (thanks Robert Hencke),
         run gotest in misc/cgo/test.
 * codereview.py: don't suggest change -d if user is not CL author (thanks Robert Hencke).
 * compress/lzw: benchmark a range of input sizes.
 * crypto/ecdsa: add package.
 * crypto/elliptic: add the N value of each curve.
 * crypto/openpgp: bug fixes and fix misnamed function.
 * crypto/tls: fix compile error (thanks Dave Cheney).
 * doc: Effective Go: some small cleanups,
         update FAQ. hello, world is now 1.1MB, down from 1.8MB,
         update codelab wiki to fix template.Execute argument order.
 * flag: visit the flags in sorted order, for nicer messages.
 * fmt: do not export EOF = -1.
 * fmt: make ScanState.Token more general (thanks Roger Peppe).
 * gc: diagnose unused labels,
         fix handling of return values named _,
         include all dependencies in export metadata,
         make unsafe.Pointer its own kind of type, instead of an equivalent to *any.
 * go/ast, go/parser: populate identifier scopes at parse time.
 * go/ast: add FileSet parameter to ast.Print and ast.Fprint.
 * go/parser: first constant in a constant declaration must have a value.
 * gob: efficiency and reliability fixes.
 * gofmt: remove -trace and -ast flags.
 * goinstall: handle $(GOOS) and $(GOARCH) in filenames,
         handle .c files with gc when cgo isn't used, and
         handle .s files with gc (thanks Gustavo Niemeyer).
 * gopack: omit time stamps, makes output deterministic.
 * gotype: commandline tool to typecheck go programs.
 * govet: handle '*' in print format strings.
 * hash: new FNV-1a implementation (thanks Pascal S. de Kloe).
 * http/cgi: child support (e.g. Go CGI under Apache).
 * http: adapt Cookie code to follow IETF draft (thanks Petar Maymounkov),
         add test for fixed HTTP/1.0 keep-alive issue,
         don't hit external network in client_test.go,
         fix transport crash when request URL is nil,
         rename interface Transport to RoundTripper,
         run tests even with DISABLE_NET_TESTS=1.
 * httptest: default the Recorder status code to 200 on a Write.
 * io/ioutil: clean-up of ReadAll and ReadFile.
 * ioutil: add NopCloser.
 * ld: preserve symbol sizes during data layout.
 * lib9, libmach: Change GOOS references to GOHOSTOS (thanks Evan Shaw).
 * libmach: correct string comparison to revive 6cov on darwin (thanks Dave Cheney).
 * misc/vim: Add indent script for Vim (thanks Ross Light).
 * net, os, syslog: fixes for Solaris support.
 * net: don't loop to drain wakeup pipe.
 * nm: document -S flag.
 * openpgp: add PublicKey KeyId string accessors.
 * rpc: optimizations, add benchmarks and memory profiling,
         use httptest.Server for tests (thanks Robert Hencke).
 * runtime: reduce lock contention via wakeup on scheduler unlock,
         scheduler, cgo reorganization,
         split non-debugging malloc interface out of debug.go into mem.go.
 * spec: clarify return statement rules.
 * strings: add IndexRune tests, ASCII fast path,
         better benchmark names; add BenchmarkIndex.
 * syscall: implement Mount and Unmount for linux,
         implement Reboot for linux.
 * time: fix Time.ZoneOffset documentation (thanks Peter Mundy).
 * tls: move PeerCertificates to ConnectionState.
 </pre>

 <h2 id="2011-03-07">2011-03-07 (<a href="release.html#r56">base for r56</a>)</h2>

 <pre>
 This release includes changes to the reflect and path packages.
 Code that uses reflect or path may need to be updated.

 The reflect package's Value.Addr method has been renamed to Value.UnsafeAddr.
 Code that uses the Addr method will have to call UnsafeAddr instead.

 The path package has been split into two packages: path and path/filepath.
 Package path manipulates slash-separated paths, regardless of operating system.
 Package filepath implements the local operating system's native file paths.
 OS-specific functioanlity in pacakge path, such as Walk, moved to filepath.

 Other changes:
 * build: fixes and simplifications (thanks Dave Cheney),
         move $GOBIN ahead of /bin, /usr/bin in build $PATH.
 * bzip2: speed up decompression.
 * cgo: fix dwarf type parsing (thanks Gustavo Niemeyer),
         put temporary source files in _obj (thanks Roger Peppe),
         fix bug involving 0-argument callbacks.
 * compress/lzw: optimizations.
 * doc: add FAQ about "implements",
         add FAQ about large binaries ,
         add FAQ about stack vs heap allocation,
         add internationalization to roadmap,
         describe platform-specific conventions in code.html.
 * fmt: allow recursive calls to Fscan etc (thanks Roger Peppe),
         make %#p suppress leading 0x.
 * gc, gopack: add some missing flags to the docs.
 * gc: fix init of packages named main (thanks Gustavo Niemeyer),
 * gob: make recursive map and slice types work, and other fixes.
         tentative support for GobEncoder/GobDecoder interfaces.
 * gobuilder: add -package flag to build external packages and -v for verbose.
 * gofmt: exclude test file that is not legal Go.
 * goinstall: protect against malicious filenames (thanks Roger Peppe).
 * goyacc: provide -p flag to set prefix for names, documentation update.
 * http: add cookie support (thanks Petar Maymounkov),
         allow handlers to send non-chunked responses,
         export ParseHTTPVersion,
         expose Client's Transport,
         use WriteProxy,
         rename ClientTransport to Transport.
 * http/cgi: new package.
 * http/httptest: new package.
 * image: add a decoding test for common file formats.
 * io/ioutil: add TempDir.
 * mime/multipart: Header changed from map to MIMEHeader
 * path/filepath: new OS-specific path support (thanks Gustavo Niemeyer).
 * reflect: add PtrTo, add Value.Addr (old Addr is now UnsafeAddr).
 * runtime: use kernel-supplied compare-and-swap on linux/arm.
 * spec: minor clarification of scope rule for functions.
 * sync/atomic: new package to expose atomic operations.
 * syscall: regenerate zerrors_freebsd_amd64.go (thanks Mikio Hara),
         work around FreeBSD execve kernel bug (thanks Devon H. O'Dell).
 * template: document the delimiters.
 * testing: run GC before each benchmark run (thanks Roger Peppe).
 * unsafe: fix the documentation.
 * websocket: use httptest.Server for tests (thanks Robert Hencke).
 * xml: permit nested directives (thanks Chris Dollin).
 </pre>

 <h2 id="2011-02-24">2011-02-24</h2>

 <pre>
 This release includes changes to the http package and a small language change.
 Your code will require changes if it manipulates http Headers or omits the
 condition in if statements.

 The new http.Header type replaces map[string]string in the Header and Trailer
 fields of http.Request and http.Response.
 A Header value can be manipulated via its Get, Set, Add, and Del methods.
 See http://golang.org/pkg/http/#Header

 The condition is now mandatory in if statements.
 Previously it would default to true, as in switch and for statements.
 This code is now illegal:
 	if x := foo(); {
 		// code that is always executed
 	}
 The same effect can be achieved like this:
 	if x := foo(); true {
 		// code
 	}
 Or, in a simpler form:
 	{
 		x := foo()
 		// code
 	}

 Other changes:
 * 6l: new -Hwindowsgui flag allows to build windows gui pe (thanks Alex Brainman),
 	pe fixes (thanks Wei Guangjing).
 * 8l, 6l: allow for more os threads to be created on Windows (thanks Alex Brainman),
 * build: reduce the use of subshells in recursive make, and
 	remove unused NaCl conditional from make.bash (thanks Dave Cheney).
 * codereview: fix clpatch with empty diffs (thanks Gustavo Niemeyer).
 * compress/bzip2: add package.
 * compress/lzw: implement a decoder.
 * crypto/openpgp: add package.
 * crypto/rand: add read buffer to speed up small requests (thanks Albert Strasheim).
 * crypto/rsa: left-pad OAEP results when needed.
 * crypto/tls: make protocol negotiation failure fatal.
 * fmt: stop giving characters to the Scan method of Scanner when we hit a newline in Scanln.
 * gc: interface error message fixes,
 	make string const comparison unsigned (thanks Jeff R. Allen).
 * go spec: minor clarification on channel types.
 * go/ast, parser: condition in if statement is mandatory.
 * gob: compute information about a user's type once.
 	protect against pure recursive types.
 * godoc: accept symbolic links as path names provided to -path,
 	add robots.txt, log errors when reading filter files.
 * html: tokenize HTML comments.
 * http: add proxy support (thanks Yasuhiro Matsumoto),
 	implement with net/textproto (thanks Petar Maymounkov),
 	send full URL in proxy requests,
 	introduce start of Client and ClientTransport.
 * image/png: support for more formats (thanks Mikael Tillenius).
 * json: only use alphanumeric tags,
 	use base64 to encode []byte (thanks Roger Peppe).
 * ld: detect stack overflow due to NOSPLIT, drop rpath, support weak symbols.
 * misc/dashboard/builder: talk to hg with utf-8 encoding.
 * misc/dashboard: notify golang-dev on build failure.
 * net: *netFD.Read to return os.EOF on eof under windows (thanks Alex Brainman),
 	add IPv4 multicast to UDPConn (thanks Dave Cheney),
 	more accurate IPv4-in-IPv6 API test (thanks Mikio Hara),
 	reject invalid net:proto network names (thanks Olivier Antoine).
 * netchan: allow use of arbitrary connections (thanks Roger Peppe).
 * os: add ENODATA and ENOTCONN (thanks Albert Strasheim).
 * reflect: add a couple of sentences explaining how Methods operate,
 	add a secret method to ArrayOrSliceType to ensure it's only implemented by arrays and slices,
 	add pointer word to CommonType (placeholder for future work).
 * runtime-gdb.py: gdb pretty printer for go strings properly handles length.
 * runtime: various bug fixes, more complete stack traces,
 	record $GOROOT_FINAL for runtime.GOROOT.
 * spec: delete incorrect mention of selector working on pointer to interface type.
 * sync: add Cond (thanks Gustavo Niemeyer).
 * syscall: add MCL_* flags for mlockall (thanks Albert Strasheim),
 	implement chmod() for win32 (thanks Yasuhiro Matsumoto).
 * test/bench: update timings for new GC.
 * testing: rename cmdline flags to avoid conflicts (thanks Gustavo Niemeyer).
 * textproto: introduce Header type (thanks Petar Maymounkov).
 * websocket: use new interface to access Header.
 </pre>

 <h2 id="2011-02-15">2011-02-15</h2>

 <pre>
 This release includes changes to the io, os, and template packages.
 You may need to update your code.

 The io.ReadByter and io.ReadRuner interface types have been renamed to
 io.ByteReader and io.RuneReader respectively.

 The os package's ForkExec function has been superseded by the new StartProcess
 function and an API built around the Process type:
 	http://golang.org/pkg/os/#Process

 The order of arguments to template.Execute has been reversed to be consistent
 the notion of "destination first", as with io.Copy, fmt.Fprint, and others.

 Gotest now works for package main in directories using Make.cmd-based makefiles.

 The memory allocation runtime problems from the last release are not completely
 fixed.  The virtual memory exhaustion problems encountered by people using
 ulimit -v have been fixed, but there remain known garbage collector problems
 when using GOMAXPROCS > 1.

 Other changes:
 * 5l: stopped generating 64-bit eor.
 * 8l: more work on plan9 support (thanks Yuval Pavel Zholkover).
 * archive/zip: handle files with data descriptors.
 * arm: working peep-hole optimizer.
 * asn1: marshal true as 255, not 1.
 * buffer.go: minor optimization, expanded comment.
 * build: drop syslog on DISABLE_NET_TESTS=1 (thanks Gustavo Niemeyer),
        allow clean.bash to work on fresh checkout,
        change "all tests pass" message to be more obvious,
        fix spaces in GOROOT (thanks Christopher Nielsen).
 * bytes: fix bug in buffer.ReadBytes (thanks Evan Shaw).
 * 5g: better int64 code,
        don't use MVN instruction.
 * cgo: don't run cgo when not compiling (thanks Gustavo Niemeyer),
        fix _cgo_run timestamp file order (thanks Gustavo Niemeyer),
        fix handling of signed enumerations (thanks Gustavo Niemeyer),
        os/arch dependent #cgo directives (thanks Gustavo Niemeyer),
        rename internal f to avoid conflict with possible C global named f.
 * codereview: fix hgpatch on windows (thanks Yasuhiro Matsumoto),
        record repository, base revision,
        use cmd.communicate (thanks Yasuhiro Matsumoto).
 * container/ring: replace Iter() with Do().
 * crypto/cipher: add resync open to OCFB mode.
 * crypto/openpgp/armor: bug fixes.
 * crypto/openpgp/packet: new subpackage.
 * crypto/tls: load a chain of certificates from a file,
        select best cipher suite, not worst.
 * crypto/x509: add support for name constraints.
 * debug/pe: ImportedSymbols fixes (thanks Wei Guangjing).
 * doc/code: update to reflect that package names need not be unique.
 * doc/codelab/wiki: a bunch of fixes (thanks Andrey Mirtchovski).
 * doc/install: update for new versions of Mercurial.
 * encoding/line: fix line returned after EOF.
 * flag: allow hexadecimal (0xFF) and octal (0377) input for integer flags.
 * fmt.Scan: scan binary-exponent floating format, 2.4p-3,
        hexadecimal (0xFF) and octal (0377) integers.
 * fmt: document %%; also %b for floating point.
 * gc, ld: detect stale or incompatible object files,
        package name main no longer reserved.
 * gc: correct receiver in method missing error (thanks Lorenzo Stoakes),
        correct rounding of denormal constants (thanks Eoghan Sherry),
        select receive bug fix.
 * go/printer, gofmt: smarter handling of multi-line raw strings.
 * go/printer: line comments must always end in a newline,
        remove notion of "Styler", remove HTML mode.
 * gob: allow Decode(nil) and have it just discard the next value.
 * godoc: use IsAbs to test for absolute paths (fix for win32) (thanks Yasuhiro Matsumoto),
        don't hide package lookup error if there's no command with the same name.
 * gotest: enable unit tests for main programs.
 * http: add Server type supporting timeouts,
        add pipelining to ClientConn, ServerConn (thanks Petar Maymounkov),
        handle unchunked, un-lengthed HTTP/1.1 responses.
 * io: add RuneReader.
 * json: correct Marshal documentation.
 * netchan: graceful handling of closed connection (thanks Graham Miller).
 * os: implement new Process API (thanks Alex Brainman).
 * regexp tests: make some benchmarks more meaningful.
 * regexp: add support for matching against text read from RuneReader interface.
 * rpc: make more tolerant of errors, properly discard values (thanks Roger Peppe).
 * runtime: detect failed thread creation on Windows,
        faster allocator, garbage collector,
        fix virtual memory exhaustion,
        implemented windows console ctrl handler (SIGINT) (thanks Hector Chu),
        more detailed panic traces, line number work,
        improved Windows callback handling (thanks Hector Chu).
 * spec: adjust notion of Assignability,
        allow import of packages named main,
        clarification re: method sets of newly declared pointer types,
        fix a few typos (thanks Anthony Martin),
        fix Typeof() return type (thanks Gustavo Niemeyer),
        move to Unicode 6.0.
 * sync: diagnose Unlock of unlocked Mutex,
        new Waitgroup type (thanks Gustavo Niemeyer).
 * syscall: add SetsockoptIpMreq (thanks Dave Cheney),
        add sockaddr_dl, sysctl with routing message support for darwin, freebsd (thanks Mikio Hara),
        do not use NULL for zero-length read, write,
        implement windows version of Fsync (thanks Alex Brainman),
        make ForkExec acquire the ForkLock under windows (thanks Hector Chu),
        make windows API return errno instead of bool (thanks Alex Brainman),
        remove obsolete socket IO control (thanks Mikio Hara).
 * template: add simple formatter chaining (thanks Kyle Consalus),
        allow a leading '*' to indirect through a pointer.
 * testing: include elapsed time in test output
 * windows: replace remaining __MINGW32__ instances with _WIN32 (thanks Joe Poirier).
 </pre>

 <h2 id="2011-02-01">2011-02-01</h2>

 <pre>
 This release includes significant changes to channel operations and minor
 changes to the log package. Your code will require modification if it uses
 channels in non-blocking communications or the log package's Exit functions.

 Non-blocking channel operations have been removed from the language.
 The equivalent operations have always been possible using a select statement
 with a default clause.  If a default clause is present in a select, that clause
 will execute (only) if no other is ready, which allows one to avoid blocking on
 a communication.

 For example, the old non-blocking send operation,

 	if ch &lt;- v {
 		// sent
 	} else {
 		// not sent
 	}

 should be rewritten as,

 	select {
 	case ch &lt;- v:
 		// sent
 	default:
 		// not sent
 	}

 Similarly, this receive,

 	v, ok := &lt;-ch
 	if ok {
 		// received
 	} else {
 		// not received
 	}

 should be rewritten as,

 	select {
 	case v := &lt;-ch:
 		// received
 	default:
 		// not received
 	}

 This change is a prelude to redefining the 'comma-ok' syntax for a receive.
 In a later release, a receive expression will return the received value and an
 optional boolean indicating whether the channel has been closed. These changes
 are being made in two stages to prevent this semantic change from silently
 breaking code that uses 'comma-ok' with receives.
 There are no plans to have a boolean expression form for sends.

 Sends to a closed channel will panic immediately. Previously, an unspecified
 number of sends would fail silently before causing a panic.

 The log package's Exit, Exitf, and Exitln functions have been renamed Fatal,
 Fatalf, and Fatalln respectively. This brings them in line with the naming of
 the testing package.

 The port to the "tiny" operating system has been removed. It is unmaintained
 and untested. It was a toy to show that Go can run on raw hardware and it
 served its purpose. The source code will of course remain in the repository
 history, so it could be brought back if needed later.

 This release also changes some of the internal structure of the memory
 allocator in preparation for other garbage collector changes.
 If you run into problems, please let us know.
 There is one known issue that we are aware of but have not debugged yet:
 	http://code.google.com/p/go/issues/detail?id=1464&amp;.

 Other changes in this release:
 * 5l: document -F, force it on old ARMs (software floating point emulation)
 * 6g: fix registerization of temporaries (thanks Eoghan Sherry),
         fix uint64(uintptr(unsafe.Pointer(&amp;x))).
 * 6l: Relocate CMOV* instructions (thanks Gustavo Niemeyer),
         windows/amd64 port (thanks Wei Guangjing).
 * 8l: add PE dynexport, emit DWARF in Windows PE, and
         code generation fixes (thanks Wei Guangjing).
 * bufio: make Flush a no-op when the buffer is empty.
 * bytes: Add Buffer.ReadBytes, Buffer.ReadString (thanks Evan Shaw).
 * cc: mode to generate go-code for types and variables.
 * cgo: define CGO_CFLAGS and CGO_LDFLAGS in Go files (thanks Gustavo Niemeyer),
         windows/386 port (thanks Wei Guangjing).
 * codereview: fix windows (thanks Hector Chu),
         handle file patterns better,
         more ASCII vs. Unicode nonsense.
 * crypto/dsa: add support for DSA.
 * crypto/openpgp: add s2k.
 * crypto/rand: use defer to unlock mutex (thanks Anschel Schaffer-Cohen).
 * crypto/rsa: correct docstring for SignPKCS1v15.
 * crypto: add package, a common place to store identifiers for hash functions.
 * doc/codelab/wiki: update to work with template changes, add to run.bash.
 * doc/spec: clarify address operators.
 * ebnflint: exit with non-zero status on error.
 * encoding/base32: new package (thanks Miek Gieben).
 * encoding/line: make it an io.Reader too.
 * exec: use custom error for LookPath (thanks Gustavo Niemeyer).
 * fmt/doc: define width and precision for strings.
 * gc: clearer error for struct == struct,
         fix send precedence,
         handle invalid name in type switch,
         special case code for single-op blocking and non-blocking selects.
 * go/scanner: fix build (adjust scanner EOF linecount).
 * gob: better debugging, commentary,
         make nested interfaces work,
         report an error when encoding a non-empty struct with no public fields.
 * godoc: full text index for whitelisted non-Go files,
         show line numbers for non-go files (bug fix).
 * gofmt -r: match(...) arguments may be nil; add missing guards.
 * govet: add Panic to the list of functions.
 * http: add host patterns (thanks Jose Luis Vázquez González),
         follow relative redirect in Get.
 * json: handle capital floating point exponent (1E100) (thanks Pieter Droogendijk).
 * ld: add -I option to set ELF interpreter,
         more robust decoding of reflection type info in generating dwarf.
 * lib9: update to Unicode 6.0.0.
 * make.bash: stricter selinux test (don't complain unless it is enabled).
 * misc/vim: Import/Drop commands (thanks Gustavo Niemeyer),
         set 'syntax sync' to a large value (thanks Yasuhiro Matsumoto).
 * net: fix race condition in test,
         return cname in LookupHost.
 * netchan: avoid race condition in test,
         fixed documentation for import (thanks Anschel Schaffer-Cohen).
 * os: add ETIMEDOUT (thanks Albert Strasheim).
 * runtime: generate Go defs for C types,
         implementation of callback functions for windows (thanks Alex Brainman),
         make Walk web browser example work (thanks Hector Chu),
         make select fairer,
         prefer fixed stack allocator over general memory allocator,
         simpler heap map, memory allocation.
 * scanner: fix Position returned by Scan, Pos,
         don't read ahead in Init.
 * suffixarray: use binary search for both ends of Lookup (thanks Eric Eisner).
 * syscall: add missing network interface constants (thanks Mikio Hara).
 * template: treat map keys as zero, not non-existent (thanks Roger Peppe).
 * time: allow cancelling of After events (thanks Roger Peppe),
         support Solaris zoneinfo directory.
 * token/position: added SetLinesForContent.
 * unicode: update to unicode 6.0.0.
 * unsafe: add missing case to doc for Pointer.
 </pre>

 <h2 id="2011-01-20">2011-01-20</h2>

 <pre>
 This release removes the float and complex types from the language.

 The default type for a floating point literal is now float64, and
 the default type for a complex literal is now complex128.

 Existing code that uses float or complex must be rewritten to
 use explicitly sized types.

 The two-argument constructor cmplx is now spelled complex.
 </pre>

 <h2 id="2011-01-19">2011-01-19</h2>

 <pre>
 The 5g (ARM) compiler now has registerization enabled.  If you discover it
 causes bugs, use 5g -N to disable the registerizer and please let us know.

 The xml package now allows the extraction of nested XML tags by specifying
 struct tags of the form "parent>child". See the XML documentation for an
 example: http://golang.org/pkg/xml/

 * 5a, 5l, 6a, 6l, 8a, 8l: handle out of memory, large allocations (thanks Jeff R. Allen).
 * 8l: pe changes (thanks Alex Brainman).
 * arm: fixes and improvements.
 * cc: fix vlong condition.
 * cgo: add complex float, complex double (thanks Sebastien Binet),
         in _cgo_main.c define all provided symbols as functions.
 * codereview: don't mail change lists with no files (thanks Ryan Hitchman).
 * crypto/cipher: add OFB mode.
 * expvar: add Float.
 * fmt: document %X of string, []byte.
 * gc, runtime: make range on channel safe for multiple goroutines.
 * gc: fix typed constant declarations (thanks Anthony Martin).
 * go spec: adjust language for constant typing.
 * go/scanner: Make Init take a *token.File instead of a *token.FileSet.
 * godoc: bring back "indexing in progress" message,
         don't double HTML-escape search result snippets,
         enable qualified identifiers ("math.Sin") as query strings again,
         peephole optimization for generated HTML,
         remove tab before formatted section.
 * gofmt, go/printer: do not insert extra line breaks where they may break the code.
 * http: fix Content-Range and Content-Length in response (thanks Clement Skau),
         fix scheme-relative URL parsing; add ParseRequestURL,
         handle HEAD requests correctly,
         support for relative URLs.
 * math: handle denormalized numbers in Frexp, Ilogb, Ldexp, and Logb (thanks Eoghan Sherry).
 * net, syscall: return source address in Recvmsg (thanks Albert Strasheim).
 * net: add LookupAddr (thanks Kyle Lemons),
         add unixpacket (thanks Albert Strasheim),
         avoid nil dereference if /etc/services can't be opened (thanks Corey Thomasson),
         implement windows timeout (thanks Wei Guangjing).
 * netchan: do not block sends; implement flow control (thanks Roger Peppe).
 * regexp: reject bare '?'. (thanks Ben Lynn)
 * runtime/cgo: don't define crosscall2 in dummy _cgo_main.c.
 * runtime/debug: new package for printing stack traces from a running goroutine.
 * runtime: add per-pause gc stats,
         fix arm reflect.call boundary case,
         print signal information during panic.
 * spec: specify that int and uint have the same size.
 * syscall: correct WSTOPPED on OS X,
         correct length of GNU/Linux abstract Unix domain sockaddr,
         correct length of SockaddrUnix.
 * tutorial: make stdin, stdout, stderr work on Windows.
 * windows: implement exception handling (thanks Hector Chu).
 </pre>

 <h2 id="2011-01-12">2011-01-12</h2>

 <pre>
 The json, gob, and template packages have changed, and code that uses them
 may need to be updated after this release. They will no longer read or write
 unexported struct fields. When marshalling a struct with json or gob the
 unexported fields will be silently ignored. Attempting to unmarshal json or
 gob data into an unexported field will generate an error. Accessing an
 unexported field from a template will cause the Execute function to return
 an error.

 Godoc now supports regular expression full text search, and this
 functionality is now available on golang.org.

 Other changes:
 * arm: initial cut at arm optimizer.
 * bytes.Buffer: Fix bug in UnreadByte.
 * cgo: export unsafe.Pointer as void*, fix enum const conflict,
         output alignment fix (thanks Gustavo Niemeyer).
 * crypto/block: mark as deprecated.
 * crypto/openpgp: add error and armor.
 * crypto: add twofish package (thanks Berengar Lehr).
 * doc/spec: remove Maxalign from spec.
 * encoding/line: new package for reading lines from an io.Reader.
 * go/ast: correct end position for Index and TypeAssert expressions.
 * gob: make (en|dec)code(Ui|I)nt methods rather than functions.
 * godefs: better handling of enums.
 * gofmt: don't attempt certain illegal rewrites,
         rewriter matches apply to expressions only.
 * goinstall: preliminary support for cgo packages (thanks Gustavo Niemeyer).
 * hg: add cgo/_cgo_* to .hgignore.
 * http: fix text displayed in Redirect.
 * ld: fix exported dynamic symbols on Mach-O,
         permit a Mach-O symbol to be exported in the dynamic symbol table.
 * log: add methods for exit and panic.
 * net: use closesocket api instead of CloseHandle on Windows (thanks Alex Brainman).
 * netchan: make fields exported for gob change.
 * os: add Sync to *File, wraps syscall.Fsync.
 * runtime/cgo: Add callbacks to support SWIG.
 * runtime: Restore scheduler stack position if cgo callback panics.
 * suffixarray: faster creation algorithm (thanks Eric Eisner).
 * syscall: fix mksysnum_linux.sh (thanks Anthony Martin).
 * time.NewTicker: panic for intervals &lt;= 0.
 * time: add AfterFunc to call a function after a duration (thanks Roger Peppe),
         fix tick accuracy when using multiple Tickers (thanks Eoghan Sherry).</pre>

 <h2 id="2011-01-06">2011-01-06</h2>

 <pre>
 This release includes several fixes and changes:

 * build: Make.pkg: use installed runtime.h for cgo.
 * cgo: disallow use of C.errno.
 * crypto/cipher: fix OCFB,
         make NewCBCEncrypter return BlockMode.
 * doc: 6l: fix documentation of -L flag,
         add golanguage.ru to foreign-language doc list,
         effective go: explain the effect of repanicking better,
         update Effective Go for template API change,
         update contribution guidelines to prefix the change description.
 * encoding/binary: reject types with implementation-dependent sizes (thanks Patrick Gavlin).
 * exp/evalsimple fix handling of slices like s[:2] (thanks Sebastien Binet).
 * fmt: made format string handling more efficient,
         normalize processing of format string.
 * gc: return constant floats for parts of complex constants (thanks Anthony Martin),
         rewrite complex /= to l = l / r (thanks Patrick Gavlin),
         fix &amp;^=.
 * go/ast: provide complete node text range info.
 * gob: generate a better error message in one confusing place.
 * godoc: fix godoc -src (thanks Icarus Sparry).
 * goinstall: add -clean flag (thanks Kyle Lemons),
         add checkout concept (thanks Caine Tighe),
         fix -u for bzr (thanks Gustavo Niemeyer).
 * http: permit empty Reason-Phrase in response Status-Line.
 * io: fix Copyn EOF handling.
 * net: fix close of Listener (thanks Michael Hoisie).
 * regexp: fix performance bug, make anchored searches fail fast,
         fix prefix bug.
 * runtime/cgo: fix stackguard on FreeBSD/amd64 (thanks Anthony Martin).
 * strconv: atof: added 'E' as valid token for exponent (thanks Stefan Nilsson),
         update ftoa comment for 'E' and 'G'.
 * strings: fix description of FieldsFunc (thanks Roger Peppe).
 * syscall: correct Linux Splice definition,
         make Access second argument consistently uint32.
 </pre>

 <h2 id="2010-12-22">2010-12-22</h2>

 <pre>
 A small release this week. The most significant change is that some
 outstanding cgo issues were resolved.

 * cgo: handle references to symbols in shared libraries.
 * crypto/elliptic: add serialisation and key pair generation.
 * crypto/hmac: add HMAC-SHA256 (thanks Anthony Martin).
 * crypto/tls: add ECDHE support ("Elliptic Curve Diffie Hellman Ephemeral"),
         add support code for generating handshake scripts for testing.
 * darwin, freebsd: ignore write failure (during print, panic).
 * exp/draw: remove Border function.
 * expvar: quote StringFunc output, same as String output.
 * hash/crc64: fix typo in Sum.
 * ld: allow relocations pointing at ELF .bss symbols, ignore stab symbols.
 * misc/cgo/life: fix, add to build.
 * regexp: add HasMeta, HasOperator, and String methods to Regexp.
 * suffixarray: implemented FindAllIndex regexp search.
 * test/bench: update numbers for regex-dna after speedup to regexp.
 * time: explain the formats a little better.
 </pre>

 <h2 id="2010-12-15">2010-12-15</h2>

 <pre>
 Package crypto/cipher has been started, to replace crypto/block.
 As part of the changes, rc4.Cipher's XORKeyStream method signature has changed from
         XORKeyStream(buf []byte)
 to
         XORKeyStream(dst, src []byte)
 to implement the cipher.Stream interface.  If you use crypto/block, you'll need
 to switch to crypto/cipher once it is complete.

 Package smtp's StartTLS now takes a *tls.Config argument.

 Package reflect's ArrayCopy has been renamed to Copy.  There are new functions
 Append and AppendSlice.

 The print/println bootstrapping functions now write to standard error.
 To write to standard output, use fmt.Print[ln].

 A new tool, govet, has been added to the Go distribution. Govet is a static
 checker for Go programs. At the moment, and for the forseeable future,
 it only checks arguments to print calls.

 The cgo tool for writing Go bindings for C code has changed so that it no
 longer uses stub .so files (like cgo_stdio.so).  Cgo-based packages using the
 standard Makefiles should build without any changes.  Any alternate build
 mechanisms will need to be updated.

 The C and Go compilers (6g, 6c, 8g, 8c, 5g, 5c) now align structs according to
 the maximum alignment of the fields they contain; previously they aligned
 structs to word boundaries.  This may break non-cgo-based code that attempts to
 mix C and Go.

 NaCl support has been removed. The recent linker changes broke NaCl support
 a month ago, and there are no known users of it.
 If necessary, the NaCl code can be recovered from the repository history.

 * 5g/8g, 8l, ld, prof: fix output of 32-bit values (thanks Eoghan Sherry).
 * [68]l and runtime: GDB support for interfaces and goroutines.
 * 6l, 8l: support for linking ELF and Mach-O .o files.
 * all: simplify two-variable ranges with unused second variable (thanks Ryan Hitchman).
 * arm: updated soft float support.
 * codereview: keep quiet when not in use (thanks Eoghan Sherry).
 * compress/flate: implement Flush, equivalent to zlib's Z_SYNC_FLUSH.
 * crypto/tls: use rand.Reader in cert generation example (thanks Anthony Martin).
 * dashboard: fix project tag filter.
 * debug/elf, debug/macho: add ImportedLibraries, ImportedSymbols.
 * doc/go_mem: goroutine exit is not special.
 * event.go: another print glitch from gocheck.
 * gc: bug fixes,
         syntax error for incomplete chan type (thanks Ryan Hitchman).
 * go/ast: fix ast.Walk.
 * gob: document the byte count used in the encoding of values,
         fix bug sending zero-length top-level slices and maps,
         Register should use the original type, not the indirected one.
 * godashboard: support submitting projects with non-ascii names (thanks Ryan Hitchman)
 * godefs: guard against structs with pad fields
 * godoc: added textual search, to enable use -fulltext flag.
 * gofmt: simplify "x, _ = range y" to "x = range y".
 * gopack: allow ELF/Mach-O objects in .a files without clearing allobj.
 * go/token,scanner: fix comments so godoc aligns properly.
 * govet: on error continue to the next file (thanks Christopher Wedgwood).
 * html: improved parsing.
 * http: ServeFile handles Range header for partial requests.
 * json: check for invalid UTF-8.
 * ld: allow .o files with no symbols,
         reading of ELF object files,
         reading of Mach-O object files.
 * math: change float64 bias constant from 1022 to 1023 (thanks Eoghan Sherry),
         rename the MinFloat constant to SmallestNonzeroFloat.
 * nm: silently ignore .o files in .a files.
 * os: fix test of RemoveAll.
 * os/inotify: new package (thanks Balazs Lecz).
 * os: make MkdirAll work with symlinks (thanks Ryan Hitchman).
 * regexp: speed up by about 30%; also simplify code for brackets.
 * runtime/linux/386: set FPU to 64-bit precision.
 * runtime: remove paranoid mapping at 0.
 * suffixarray: add Bytes function.
 * syscall: add network interface constants for linux/386, linux/amd64 (thanks Mikio Hara).
 * syscall/windows: restrict access rights param of OpenProcess(),
         remove \r and \n from error messages (thanks Alex Brainman).
 * test/bench: fixes to timing.sh (thanks Anthony Martin).
 * time: fix bug in Ticker: shutdown using channel rather than memory.
 * token/position: provide FileSet.File, provide files iterator.
 * xml: disallow invalid Unicode code points (thanks Nigel Kerr).
 </pre>

 <h2 id="2010-12-08">2010-12-08</h2>

 <pre>
 This release includes some package changes. If you use the crypto/tls or
 go/parser packages your code may require changes.

 The crypto/tls package's Dial function now takes an additional *Config
 argument.  Most uses will pass nil to get the same default behavior as before.
 See the documentation for details:
         http://golang.org/pkg/crypto/tls/#Config
         http://golang.org/pkg/crypto/tls/#Dial

 The go/parser package's ParseFile function now takes a *token.FileSet as its
 first argument. This is a pointer to a data structure used to store
 position information. If you don't care about position information you
 can pass "token.NewFileSet()". See the documentation for details:
         http://golang.org/pkg/go/parser/#ParseFile

 This release also splits the patent grant text out of the LICENSE file into a
 separate PATENTS file and changes it to be more like the WebM grant.
 These clarifications were made at the request of the Fedora project.

 Other changes:
 * [68]l: generate debug info for builtin structured types, prettyprinting in gdb.
 * 8l: add dynimport to import table in Windows PE (thanks Wei Guangjing).
 * 8l, runtime: fix Plan 9 386 build (thanks Yuval Pavel Zholkover).
 * all: fix broken calls to Printf etc.
 * bufio: make Reader.Read implement io.Reader semantics (thanks Roger Peppe).
 * build: allow archiver to be specified by HOST_AR (thanks Albert Strasheim).
 * bytes: add Buffer.UnreadRune, Buffer.UnreadByte (thanks Roger Peppe).
 * crypto/tls: fix build of certificate generation example (thanks Christian Himpel).
 * doc/install: describe GOHOSTOS and GOHOSTARCH.
 * errchk: accept multiple source files (thanks Eoghan Sherry).
 * exec.LookPath: return os.PathError instad of os.ENOENT (thanks Michael Hoisie)..
 * flag: fix format error in boolean error report,
         handle multiple calls to flag.Parse.
 * fmt: add %U format for standard Unicode representation of code point values.
 * gc: fix method offsets of anonymous interfaces (thanks Eoghan Sherry),
         skip undefined symbols in import . (thanks Eoghan Sherry).
 * go/scanner: remove Tokenize - was only used in tests
 * gobuilder: add buildroot command-line flag (thanks Devon H. O'Dell).
 * html: unescape numeric entities (thanks Ryan Hitchman).
 * http: Add EncodeQuery, helper for constructing query strings.
 * ld: fix dwarf decoding of 64-bit reflect values (thanks Eoghan Sherry).
 * math: improve accuracy of Exp2 (thanks Eoghan Sherry).
 * runtime: add Goroutines (thanks Keith Rarick).
 * sync: small naming fix for armv5 (thanks Dean Prichard).
 * syscall, net: Add Recvmsg and Sendmsg on Linux (thanks Albert Strasheim).
 * time: make After use fewer goroutines and host processes (thanks Roger Peppe).
 </pre>

 <h2 id="2010-12-02">2010-12-02</h2>

 <pre>
 Several package changes in this release may require you to update your code if
 you use the bytes, template, or utf8 packages. In all cases, any outdated code
 will fail to compile rather than behave erroneously.

 The bytes package has changed. Its Add and AddByte functions have been removed,
 as their functionality is provided by the recently-introduced built-in function
 "append". Any code that uses them will need to be changed:
 s = bytes.Add(s, b)    -&gt;    s = append(s, b...)
 s = bytes.AddByte(b, c)    -&gt;    s = append(s, b)
 s = bytes.Add(nil, c)    -&gt;    append([]byte(nil), c)

 The template package has changed. Your code will need to be updated if it calls
 the HTMLFormatter or StringFormatter functions, or implements its own formatter
 functions. The function signature for formatter types has changed to:
         func(wr io.Writer, formatter string, data ...interface{})
 to allow multiple arguments to the formatter.  No templates will need updating.
 See the change for examples:
         http://code.google.com/p/go/source/detail?r=2c2be793120e

 The template change permits the implementation of multi-word variable
 instantiation for formatters. Before one could say
         {field}
 or
         {field|formatter}
 Now one can also say
         {field1 field2 field3}
 or
         {field1 field2 field3|formatter}
 and the fields are passed as successive arguments to the formatter,
 by analogy to fmt.Print.

 The utf8 package has changed. The order of EncodeRune's arguments has been
 reversed to satisfy the convention of "destination first".
 Any code that uses EncodeRune will need to be updated.

 Other changes:
 * [68]l: correct dwarf location for globals and ranges for arrays.
 * big: fix (*Rat) SetFrac64(a, b) when b &lt; 0 (thanks Eoghan Sherry).
 * compress/flate: fix typo in comment (thanks Mathieu Lonjaret).
 * crypto/elliptic: use a Jacobian transform for better performance.
 * doc/code.html: fix reference to "gomake build" (thanks Anschel Schaffer-Cohen).
 * doc/roadmap: update gdb status.
 * doc/spec: fixed some omissions and type errors.
 * doc: some typo fixes (thanks Peter Mundy).
 * exp/eval: build fix for parser.ParseFile API change (thanks Anschel Schaffer-Cohen).
 * fmt: Scan accepts Inf and NaN,
         allow "% X" as well as "% x".
 * go/printer: preserve newlines in func parameter lists (thanks Jamie Gennis).
 * http: consume request body before next request.
 * log: ensure writes are atomic (thanks Roger Peppe).
 * path: Windows support for Split (thanks Benny Siegert).
 * runtime: fix SysFree to really free memory on Windows (thanks Alex Brainman),
         parallel definitions in Go for all C structs.
 * sort: avoid overflow in pivot calculation,
         reduced stack depth to lg(n) in quickSort (thanks Stefan Nilsson).
 * strconv: Atof on Infs and NaNs.
 </pre>

 <h2 id="2010-11-23">2010-11-23</h2>

 <pre>
 This release includes a backwards-incompatible package change to the
 sort.Search function (introduced in the last release).
 See the change for details and examples of how you might change your code:
         http://code.google.com/p/go/source/detail?r=102866c369

 * build: automatically #define _64BIT in 6c.
 * cgo: print required space after parameter name in wrapper function.
 * crypto/cipher: new package to replace crypto/block (thanks Adam Langley).
 * crypto/elliptic: new package, implements elliptic curves over prime fields (thanks Adam Langley).
 * crypto/x509: policy OID support and fixes (thanks Adam Langley).
 * doc: add link to codewalks,
         fix recover() documentation (thanks Anschel Schaffer-Cohen),
         explain how to write Makefiles for commands.
 * exec: enable more tests on windows (thanks Alex Brainman).
 * gc: adjustable hash code in typecheck of composite literals
         (thanks to vskrap, Andrey Mirtchovski, and Eoghan Sherry).
 * gc: better error message for bad type in channel send (thanks Anthony Martin).
 * godoc: bug fix in relativePath,
         compute search index for all file systems under godoc's observation,
         use correct time stamp to indicate accuracy of search result.
 * index/suffixarray: use sort.Search.
 * net: add ReadFrom and WriteTo windows version (thanks Wei Guangjing).
 * reflect: remove unnecessary casts in Get methods.
 * rpc: add RegisterName to allow override of default type name.
 * runtime: free memory allocated by windows CommandLineToArgv (thanks Alex Brainman).
 * sort: simplify Search (thanks Roger Peppe).
 * strings: add LastIndexAny (thanks Benny Siegert).
 </pre>

 <h2 id="2010-11-10">2010-11-10</h2>

 <pre>
 The birthday release includes a new Search capability inside the sort package.
 It takes an unusual but very general and easy-to-use approach to searching
 arbitrary indexable sorted data.  See the documentation for details:
     http://golang.org/pkg/sort/#Search

 The ARM port now uses the hardware floating point unit (VFP).  It still has a
 few bugs, mostly around conversions between unsigned integer and floating-point
 values, but it's stabilizing.

 In addition, there have been many smaller fixes and updates:

 * 6l: generate dwarf variable names with disambiguating suffix.
 * container/list: make Remove return Value of removed element.
     makes it easier to remove first or last item.
 * crypto: add cast5 (default PGP cipher),
     switch block cipher methods to be destination first.
 * crypto/tls: use pool building for certificate checking
 * go/ast: change embedded token.Position fields to named fields
     (preparation for a different position representation)
 * net: provide public access to file descriptors (thanks Keith Rarick)
 * os: add Expand function to evaluate environment variables.
 * path: add Glob (thanks Benny Siegert)
 * runtime: memequal optimization (thanks Graham Miller)
     prefix all external symbols with "runtime·" to avoid
     conflicts linking with external C libraries.
 </pre>

 <h2 id="2010-11-02">2010-11-02</h2>

 <pre>
 This release includes a language change: the new built-in function, append.
 Append makes growing slices much simpler. See the spec for details:
         http://golang.org/doc/go_spec.html#Appending_and_copying_slices

 Other changes:
 * 8l: pe generation fixes (thanks Alex Brainman).
 * doc: Effective Go: append and a few words about "..." args.
 * build: fiddle with make variables.
 * codereview: fix sync and download in Python 2.7 (thanks Fazlul Shahriar).
 * debug/pe, cgo: add windows support (thanks Wei Guangjing).
 * go/ast: add Inspect function for easy AST inspection w/o a visitor.
 * go/printer: do not remove parens around composite literals starting with
         a type name in control clauses.
 * go/scanner: bug fixes, revisions, and more tests.
 * gob: several fixes and documentation updates.
 * godoc: bug fix (bug introduced with revision 3ee58453e961).
 * gotest: print empty benchmark list in a way that gofmt will leave alone.
 * http server: correctly respond with 304 NotModified (thanks Michael Hoisie).
 * kate: update list of builtins (thanks Evan Shaw).
 * libutf: update to Unicode 5.2.0 to match pkg/unicode (thanks Anthony Martin).
 * misc/bbedit: update list of builtins (thanks Anthony Starks).
 * misc/vim: update list of builtins.
 * mkrunetype: install a Makefile and tweak it slightly so it can be built.
 * netchan: fix locking bug.
 * pidigits: minor improvements (thanks Evan Shaw).
 * rpc: fix client deadlock bug.
 * src: use append where appropriate (often instead of vector).
 * strings: add Contains helper function (thanks Brad Fitzpatrick).
 * syscall: SIO constants for Linux (thanks Albert Strasheim),
         Stat(path) on windows (thanks Alex Brainman).
 * test/ken/convert.go: add conversion torture test.
 * testing: add Benchmark (thanks Roger Peppe).
 </pre>

 <h2 id="2010-10-27">2010-10-27</h2>

 <pre>
 *** This release changes the encoding used by package gob.
     If you store gobs on disk, see below. ***

 The ARM port (5g) now passes all tests. The optimizer is not yet enabled, and
 floating point arithmetic is performed entirely in software. Work is underway
 to address both of these deficiencies.

 The syntax for arrays, slices, and maps of composite literals has been
 simplified. Within a composite literal of array, slice, or map type, elements
 that are themselves composite literals may elide the type if it is identical to
 the outer literal's element type. For example, these expressions:
 	[][]int{[]int{1, 2, 3}, []int{4, 5}}
 	map[string]Point{"x": Point{1.5, -3.5}, "y": Point{0, 0}}
 can be simplified to:
 	[][]int{{1, 2, 3}, {4, 5}}
 	map[string]Point{"x": {1.5, -3.5}, "y": {0, 0}}
 Gofmt can make these simplifications mechanically when invoked with the
 new -s flag.

 The built-in copy function can now copy bytes from a string value to a []byte.
 Code like this (for []byte b and string s):
 	for i := 0; i &lt; len(s); i++ {
 		b[i] = s[i]
 	}
 can be rewritten as:
 	copy(b, s)

 The gob package can now encode and decode interface values containing types
 registered ahead of time with the new Register function. These changes required
 a backwards-incompatible change to the wire format.  Data written with the old
 version of the package will not be readable with the new one, and vice versa.
 (Steps were made in this change to make sure this doesn't happen again.)
 We don't know of anyone using gobs to create permanent data, but if you do this
 and need help converting, please let us know, and do not update to this release
 yet.  We will help you convert your data.

 Other changes:
 * 5g, 6g, 8g: generate code for string index instead of calling function.
 * 5l, 6l, 8l: introduce sub-symbols.
 * 6l/8l: global and local variables and type info.
 * Make.inc: delete unnecessary -fno-inline flag to quietgcc.
 * arm: precise float64 software floating point, bug fixes.
 * big: arm assembly, faster software mulWW, divWW.
 * build: only print "You need to add foo to PATH" when needed.
 * container/list: fix Remove bug and use pointer to self as identifier.
 * doc: show page title in browser title bar,
         update roadmap.
 * encoding/binary: give LittleEndian, BigEndian specific types.
 * go/parser: consume auto-inserted semi when calling ParseExpr().
 * gobuilder: pass GOHOSTOS and GOHOSTARCH to build,
         write build and benchmarking logs to disk.
 * goinstall: display helpful message when encountering a cgo package,
         fix test for multiple package names (thanks Fazlul Shahriar).
 * gotest: generate correct gofmt-formatted _testmain.go.
 * image/png: speed up paletted encoding ~25% (thanks Brad Fitzpatrick).
 * misc: update python scripts to specify python2 as python3 is now "python".
 * net: fix comment on Dial to mention unix/unixgram.
 * rpc: expose Server type to allow multiple RPC Server instances.
 * runtime: print unknown types in panic.
 * spec: append built-in (not yet implemented).
 * src: gofmt -s -w src misc.
         update code to use copy-from-string.
 * test/bench: update numbers.
 * websocket: fix short Read.
 </pre>

 <h2 id="2010-10-20">2010-10-20</h2>

 <pre>
 This release removes the log package's deprecated functions.
 Code that has not been updated to use the new interface will break.
 See the previous release notes for details:
 	http://golang.org/doc/devel/release.html#2010-10-13

 Also included are major improvements to the linker. It is now faster,
 uses less memory, and more parallelizable (but not yet parallel).

 The nntp package has been removed from the standard library.
 Its new home is the nntp-go project at Google Code:
 	http://code.google.com/p/nntp-go
 You can install it with goinstall:
 	goinstall nntp-go.googlecode.com/hg/nntp
 And import it in your code like so:
 	import "nntp-go.googlecode.com/hg/nntp"

 Other changes:
 * 6g: avoid too-large immediate constants.
 * 8l, runtime: initial support for Plan 9 (thanks Yuval Pavel Zholkover).
 * 6l, 8l: more improvements on exporting debug information (DWARF).
 * arm: code gen fixes. Most tests now pass, except for floating point code.
 * big: add random number generation (thanks Florian Uekermann).
 * gc: keep track of real actual type of identifiers,
 	report that shift must be unsigned integer,
 	select receive with implicit conversion.
 * goplay: fix to run under windows (thanks Yasuhiro Matsumoto).
 * http: do not close connection after sending HTTP/1.0 request.
 * netchan: add new method Hangup to terminate transmission on a channel.
 * os: change TestForkExec so it can run on windows (thanks Yasuhiro Matsumoto).
 * runtime: don't let select split stack.
 * syscall/arm: correct 64-bit system call arguments.
 </pre>

 <h2 id="2010-10-13">2010-10-13</h2>

 <pre>
 This release includes changes to the log package, the removal of exp/iterable,
 two new tools (gotry and goplay), one small language change, and many other
 changes and fixes.  If you use the log or iterable packages, you need to make
 changes to your code.

 The log package has changed.  Loggers now have only one output, and output to
 standard error by default.  The names have also changed, although the old names
 are still supported.  They will be deleted in the next release, though, so it
 would be good to update now if you can.  For most purposes all you need to do
 is make these substitutions:
         log.Stderr -&gt; log.Println or log.Print
         log.Stderrf -&gt; log.Printf
         log.Crash -&gt; log.Panicln or log.Panic
         log.Crashf -&gt; log.Panicf
         log.Exit -&gt; log.Exitln or log.Exit
         log.Exitf -&gt; log.Exitf (no change)
 Calls to log.New() must drop the second argument.
 Also, custom loggers with exit or panic properties will need to be reworked.
 For full details, see the change description:
         http://code.google.com/p/go/source/detail?r=d8a3c7563d

 The language change is that uses of pointers to interface values no longer
 automatically dereference the pointer.  A pointer to an interface value is more
 often a beginner's bug than correct code.

 The package exp/iterable has been removed. It was an interesting experiment,
 but it encourages writing inefficient code and has outlived its utility.

 The new tools:
 * gotry: an exercise in reflection and an unusual tool. Run 'gotry' for details.
 * goplay: a stand-alone version of the Go Playground. See misc/goplay.

 Other changes:
 * 6l: Mach-O fixes, and fix to work with OS X nm/otool (thanks Jim McGrath).
 * [568]a: correct line numbers for statements.
 * arm: code generation and runtime fixes,
 	adjust recover for new reflect.call,
 	enable 6 more tests after net fix.
 * big: fix panic and round correctly in Rat.FloatString (thanks Anthony Martin).
 * build: Make.cmd: remove $(OFILES) (thanks Eric Clark),
         Make.pkg: remove .so before installing new one,
         add GOHOSTOS and GOHOSTARCH environment variables.
 * crypto/tls: better error messages for certificate issues,
         make SetReadTimeout work.
 * doc: add Sydney University video,
 	add The Expressiveness of Go talk.
 * exp/draw/x11: support X11 vendors other than "The X.Org Foundation".
 * expvar: add (*Int).Set (thanks Sam Thorogood).
 * fmt: add Errorf helper function,
         allow %d on []byte.
 * gc: O(1) string comparison when lengths differ,
         various bug fixes.
 * http: return the correct error if a header line is too long.
 * image: add image.Tiled type, the Go equivalent of Plan 9's repl bit.
 * ld: be less picky about bad line number info.
 * misc/cgo/life: fix for new slice rules (thanks Graham Miller).
 * net: allow _ in DNS names.
 * netchan: export before import when testing, and
         zero out request to ensure correct gob decoding. (thanks Roger Peppe).
 * os: make tests work on windows (thanks Alex Brainman).
 * runtime: bug fix: serialize mcache allocation,
         correct iteration of large map values,
         faster strequal, memequal (thanks Graham Miller),
         fix argument dump in traceback,
         fix tiny build.
 * smtp: new package (thanks Evan Shaw).
 * syscall: add sockaddr_ll support for linux/386, linux/amd64 (thanks Mikio Hara),
         add ucred structure for SCM_CREDENTIALS over UNIX sockets. (thanks Albert Strasheim).
 * syscall: implement WaitStatus and Wait4() for windows (thanks Wei Guangjing).
 * time: add After.
 * websocket: enable tests on windows (thanks Alex Brainman).
 </pre>

 <h2 id="2010-09-29">2010-09-29</h2>

 <pre>
 This release includes some minor language changes and some significant package
 changes. You may need to change your code if you use ...T parameters or the
 http package.

 The semantics and syntax of forwarding ...T parameters have changed.
         func message(f string, s ...interface{}) { fmt.Printf(f, s) }
 Here, s has type []interface{} and contains the parameters passed to message.
 Before this language change, the compiler recognized when a function call
 passed a ... parameter to another ... parameter of the same type, and just
 passed it as though it was a list of arguments.  But this meant that you
 couldn't control whether to pass the slice as a single argument and you
 couldn't pass a regular slice as a ... parameter, which can be handy.  This
 change gives you that control at the cost of a few characters in the call.
 If you want the promotion to ...,  append ... to the argument:
         func message(f string, s ...interface{}) { fmt.Printf(f, s...) }
 Without the ..., s would be passed to Printf as a single argument of type
 []interface{}.  The bad news is you might need to fix up some of your code,
 but the compiler will detect the situation and warn you.

 Also, the http.Handler and http.HandlerFunc types have changed. Where http
 handler functions previously accepted an *http.Conn, they now take an interface
 type http.ResponseWriter. ResponseWriter implements the same methods as *Conn,
 so in most cases the only change required will be changing the type signature
 of your handler function's first parameter. See:
   http://golang.org/pkg/http/#Handler

 The utf8 package has a new type, String, that provides efficient indexing
 into utf8 strings by rune (previously an expensive conversion to []int
 was required). See:
   http://golang.org/pkg/utf8/#String

 The compiler will now automatically insert a semicolon at the end of a file if
 one is not found. This effect of this is that Go source files are no longer
 required to have a trailing newline.

 Other changes:
 * 6prof: more accurate usage message.
 * archive/zip: new package for reading Zip files.
 * arm: fix code generation, 10 more package tests pass.
 * asn1: make interface consistent with json.
 * bufio.UnreadRune: fix bug at EOF.
 * build: clear custom variables like GREP_OPTIONS,
         silence warnings generated by ubuntu gcc,
         use full path when compiling libraries.
 * bytes, strings: change lastIndexFunc to use DecodeLastRune (thanks Roger Peppe).
 * doc: add to and consolidate non-english doc references,
         consolidate FAQs into a single file, go_faq.html,
         updates for new http interface.
 * fmt/Printf: document and tweak error messages produced for bad formats.
 * gc: allow select case expr = &lt;-c,
         eliminate duplicates in method table,
         fix reflect table method receiver,
         improve error message for x \= 0.
 * go/scanner: treat EOF like a newline for purposes of semicolon insertion.
 * gofmt: stability improvements.
 * gotest: leave _testmain.go for "make clean" to clean up.
 * http: correct escaping of different parts of URL,
         support HTTP/1.0 Keep-Alive.
 * json: do not write to unexported fields.
 * libcgo: don't build for NaCl,
         set g, m in thread local storage for windows 386 (thanks Wei Guangjing).
 * math: Fix off-by-one error in Ilogb and Logb.  (thanks Charles L. Dorian).
 * misc/dashboard/builder: remove build files after benchmarking.
 * nacl: update instructions for new SDK.
 * net: enable v4-over-v6 on ip sockets,
         fix crash in DialIP.
 * os: check for valid arguments in windows Readdir (thanks Peter Mundy).
 * runtime: add mmap of null page just in case,
         correct stats in SysFree,
         fix unwindstack crash.
 * syscall: add IPPROTO_IPV6 and IPV6_V6ONLY const to fix nacl and windows build,
         add inotify on Linux (thanks Balazs Lecz),
         fix socketpair in syscall_bsd,
         fix windows value of IPV6_V6ONLY (thanks Alex Brainman),
         implement windows version of Utimes (thanks Alex Brainman),
         make mkall.sh work for nacl.
 * test: Add test that causes incorrect error from gccgo.
 * utf8: add DecodeLastRune and DecodeLastRuneInString (thanks Roger Peppe).
 * xml: Allow entities inside CDATA tags (thanks Dan Sinclair).
 </pre>

 <h2 id="2010-09-22">2010-09-22</h2>

 <pre>
 This release includes new package functionality, and many bug fixes and changes.
 It also improves support for the arm and nacl platforms.

 * 5l: avoid fixed buffers in list.
 * 6l, 8l: clean up ELF code, fix NaCl.
 * 6l/8l: emit DWARF frame info.
 * Make.inc: make GOOS detection work on windows (thanks Alex Brainman).
 * build: fixes for native arn build,
         make all.bash run on Ubuntu ARM.
 * cgo: bug fixes,
         show preamble gcc errors (thanks Eric Clark).
 * crypto/x509, crypto/tls: improve root matching and observe CA flag.
 * crypto: Fix certificate validation.
 * doc: variable-width layout.
 * env.bash: fix building in directory with spaces in the path (thanks Alex Brainman).
 * exp/4s, exp/nacl/av: sync to recent exp/draw changes.
 * exp/draw/x11: mouse location is a signed integer.
 * exp/nacl/av: update color to max out at 1&lt;&lt;16-1 instead of 1&lt;&lt;32-1.
 * fmt: support '*' for width or precision (thanks Anthony Martin).
 * gc: improvements to static initialization,
         make sure path names are canonical.
 * gob: make robust when decoding a struct with non-struct data.
 * gobuilder: add -cmd for user-specified build command,
         add -rev= flag to build specific revision and exit,
         fix bug that caused old revisions to be rebuilt.
 * godoc: change default filter file name to "",
         don't use quadratic algorithm to filter paths,
         show "Last update" info for directory listings.
 * http: new redirect test,
         URLEscape now escapes all reserved characters as per the RFC.
 * nacl: fix zero-length writes.
 * net/dict: parse response correctly (thanks Fazlul Shahriar).
 * netchan: add a cross-connect test,
         handle closing of channels,
         provide a method (Importer.Errors()) to recover protocol errors.
 * os: make Open() O_APPEND flag work on windows (thanks Alex Brainman),
         make RemoveAll() work on windows (thanks Alex Brainman).
 * pkg/Makefile: disable netchan test to fix windows build (thanks Alex Brainman).
 * regexp: delete Iter methods.
 * runtime: better panic for send to nil channel.
 * strings: fix minor bug in LastIndexFunc (thanks Roger Peppe).
 * suffixarray: a package for creating suffixarray-based indexes.
 * syscall: Use vsyscall for syscall.Gettimeofday and .Time on linux amd64.
 * test: fix NaCl build.
 * windows: fix netchan test by using 127.0.0.1.
 </pre>

 <h2 id="2010-09-15">2010-09-15</h2>

 <pre>
 This release includes a language change: the lower bound of a subslice may
 now be omitted, in which case the value will default to 0.
 For example, s[0:10] may now be written as s[:10], and s[0:] as s[:].

 The release also includes important bug fixes for the ARM architecture,
 as well as the following fixes and changes:

 * 5g: register allocation bugs
 * 6c, 8c: show line numbers in -S output
 * 6g, 6l, 8g, 8l: move read-only data to text segment
 * 6l, 8l: make etext accurate; introduce rodata, erodata.
 * arm: fix build bugs.
         make libcgo build during OS X cross-compile
         remove reference to deleted file syntax/slice.go
         use the correct stat syscalls
         work around reg allocator bug in 5g
 * bufio: add UnreadRune.
 * build: avoid bad environment interactions
         fix build for tiny
         generate, clean .exe files on Windows (thanks Joe Poirier)
         test for _WIN32, not _MINGW32 (thanks Joe Poirier)
         work with GNU Make 3.82 (thanks Jukka-Pekka Kekkonen)
 * cgo: add typedef for uintptr in generated headers
         silence warning for C call returning const pointer
 * codereview: convert email address to lower case before checking CONTRIBUTORS
 * crypto/tls: don't return an error from Close()
 * doc/tutorial: update for slice changes.
 * exec: separate LookPath implementations for unix/windows (thanks Joe Poirier)
 * exp/draw/x11: allow clean shutdown when the user closes the window.
 * exp/draw: clip destination rectangle to the image bounds.
         fast path for drawing overlapping image.RGBAs.
         fix double-counting of pt.Min for the src and mask points.
         reintroduce the MouseEvent.Nsec timestamp.
         rename Context to Window, and add a Close method.
 * exp/debug: preliminary support for 'copy' function (thanks Sebastien Binet)
 * fmt.Fscan: use UnreadRune to preserve data across calls.
 * gc: better printing of named constants, func literals in errors
         many bug fixes
         fix line number printing with //line directives
         fix symbol table generation on windows (thanks Alex Brainman)
         implement comparison rule from spec change 33abb649cb63
         implement new slice spec (thanks Scott Lawrence)
         make string x + y + z + ... + w efficient
         more accurate line numbers for ATEXT
         remove &amp;[10]int -&gt; []int conversion
 * go-mode.el: fix highlighting for 'chan' type (thanks Scott Lawrence)
 * godoc: better support for directory trees for user-supplied paths
         use correct delay time (bug fix)
 * gofmt, go/printer: update internal estimated position correctly
 * goinstall: warn when package name starts with http:// (thanks Scott Lawrence)
 * http: check https certificate against host name
         do not cache CanonicalHeaderKey (thanks Jukka-Pekka Kekkonen)
 * image: change a ColorImage's minimum point from (0, 0) to (-1e9, -1e9).
         introduce Intersect and Union rectangle methods.
 * ld: handle quoted spaces in package path (thanks Dan Sinclair)
 * libcgo: fix NaCl build.
 * libmach: fix build on arm host
         fix new thread race with Linux
 * math: make portable Tan(Pi/2) return NaN
 * misc/dashboard/builder: gobuilder, a continuous build client
 * net: disable tests for functions not available on windows (thanks Alex Brainman)
 * netchan: make -1 unlimited, as advertised.
 * os, exec: rename argv0 to name
 * path: add IsAbs (thanks Ivan Krasin)
 * runtime: fix bug in tracebacks
         fix crash trace on amd64
         fix windows build (thanks Alex Brainman)
         use manual stack for garbage collection
 * spec: add examples for slices with omitted index expressions.
         allow omission of low slice bound (thanks Scott Lawrence)
 * syscall: fix windows Gettimeofday (thanks Alex Brainman)
 * test(arm): disable zerodivide.go because compilation fails.
 * test(windows): disable tests that cause the build to fail (thanks Joe Poirier)
 * test/garbage/parser: sync with recent parser changes
 * test: Add test for //line
         Make gccgo believe that the variables can change.
         Recognize gccgo error messages.
         Reduce race conditions in chan/nonblock.go.
         Run garbage collector before testing malloc numbers.
 * websocket: Add support for secure WebSockets (thanks Jukka-Pekka Kekkonen)
 * windows: disable unimplemented tests (thanks Joe Poirier)
 </pre>

 <h2 id="2010-09-06">2010-09-06</h2>

 <pre>
 This release includes the syntactic modernization of more than 100 files in /test,
 and these additions, changes, and fixes:
 * 6l/8l: emit DWARF in macho.
 * 8g: use FCHS, not FMUL, for minus float.
 * 8l: emit DWARF in ELF,
         suppress emitting DWARF in Windows PE (thanks Alex Brainman).
 * big: added RatString, some simplifications.
 * build: create bin and pkg directories as needed; drop from hg,
         delete Make.386 Make.amd64 Make.arm (obsoleted by Make.inc),
         fix cgo with -j2,
         let pkg/Makefile coordinate building of Go commands,
         never use quietgcc in Make.pkg,
         remove more references to GOBIN and GOROOT (thanks Christian Himpel).
 * codereview: Fix uploading for Mercurial 1.6.3 (thanks Evan Shaw),
         consistent indent, cut dead code,
         fix hang on standard hg commands,
         print status when tasks take longer than 30 seconds,
         really disable codereview when not available,
         upload files in parallel (5x improvement on large CLs).
 * crypto/hmac: make Sum idempotent (thanks Jukka-Pekka Kekkonen).
 * doc: add links to more German docs,
         add round-robin flag to io2010 balance example,
         fix a bug in the example in Constants subsection (thanks James Fysh),
         various changes for validating HTML (thanks Scott Lawrence).
 * fmt: delete erroneous sentence about return value for Sprint*.
 * gc: appease bison version running on FreeBSD builder,
         fix spurious syntax error.
 * go/doc: use correct escaper for URL.
 * go/printer: align ImportPaths in ImportDecls (thanks Scott Lawrence).
 * go/typechecker: 2nd step towards augmenting AST with full type information.
 * gofmt: permit omission of first index in slice expression.
 * goinstall: added -a flag to mean "all remote packages" (thanks Scott Lawrence),
         assume go binaries are in path (following new convention),
         use https for Google Code checkouts.
 * gotest: allow make test of cgo packages (without make install).
 * http: add Date to server, Last-Modified and If-Modified-Since to file server,
         add PostForm function to post url-encoded key/value data,
         obscure passwords in return value of URL.String (thanks Scott Lawrence).
 * image: introduce Config type and DecodeConfig function.
 * libcgo: update Makefile to use Make.inc.
 * list: update comment to state that the zero value is ready to use.
 * math: amd64 version of Sincos (thanks Charles L. Dorian).
 * misc/bash: add *.go completion for gofmt (thanks Scott Lawrence).
 * misc/emacs: make _ a word symbol (thanks Scott Lawrence).
 * misc: add zsh completion (using compctl),
         syntax highlighting for Fraise.app (OS X) (thanks Vincent Ambo).
 * net/textproto: Handle multi-line responses (thanks Evan Shaw).
 * net: add LookupMX (thanks Corey Thomasson).
 * netchan: Fix race condition in test,
         rather than 0, make -1 mean infinite (a la strings.Split et al),
         use acknowledgements on export send.
         new methods Sync and Drain for clean teardown.
 * regexp: interpret all Go characer escapes \a \b \f \n \r \t \v.
 * rpc: fix bug that caused private methods to attempt to be registered.
 * runtime: Correct commonType.kind values to match compiler,
         add GOOS, GOARCH; fix FuncLine,
         special case copy, equal for one-word interface values (thanks Kyle Consalus).
 * scanner: fix incorrect reporting of error in Next (thanks Kyle Consalus).
 * spec: clarify that arrays must be addressable to be sliceable.
 * template: fix space handling around actions.
 * test/solitaire: an exercise in backtracking and string conversions.
 * test: Recognize gccgo error messages and other fixes.
 * time: do not crash in String on nil Time.
 * tutorial: regenerate HTML to pick up change to progs/file.go.
 * websocket: fix missing Sec-WebSocket-Protocol on server response (thanks Jukka-Pekka Kekkonen).
 </pre>

 <h2 id="2010-08-25">2010-08-25</h2>

 <pre>
 This release includes changes to the build system that will likely require you
 to make changes to your environment variables and Makefiles.

 All environment variables are now optional:
  - $GOOS and $GOARCH are now optional; their values should now be inferred
    automatically by the build system,
  - $GOROOT is now optional, but if you choose not to set it you must run
    'gomake' instead of 'make' or 'gmake' when developing Go programs
    using the conventional Makefiles,
  - $GOBIN remains optional and now defaults to $GOROOT/bin;
    if you wish to use this new default, make sure it is in your $PATH
    and that you have removed the existing binaries from $HOME/bin.

 As a result of these changes, the Go Makefiles have changed. If your Makefiles
 inherit from the Go Makefiles, you must change this line:
     include ../../Make.$(GOARCH)
 to this:
     include ../../Make.inc

 This release also removes the deprecated functions in regexp and the
 once package. Any code that still uses them will break.
 See the notes from the last release for details:
     http://golang.org/doc/devel/release.html#2010-08-11

 Other changes:
 * 6g: better registerization for slices, strings, interface values
 * 6l: line number information in DWARF format
 * build: $GOBIN defaults to $GOROOT/bin,
         no required environment variables
 * cgo: add C.GoStringN (thanks Eric Clark).
 * codereview: fix issues with leading tabs in CL descriptions,
         do not send "Abandoned" mail if the CL has not been mailed.
 * crypto/ocsp: add missing Makefile.
 * crypto/tls: client certificate support (thanks Mikkel Krautz).
 * doc: update gccgo information for recent changes.
         fix errors in Effective Go.
 * fmt/print: give %p priority, analogous to %T,
         honor Formatter in Print, Println.
 * gc: fix parenthesization check.
 * go/ast: facility for printing AST nodes,
         first step towards augmenting AST with full type information.
 * go/printer: do not modify tabwriter.Escape'd text.
 * gofmt: do not modify multi-line string literals,
         print AST nodes by setting -ast flag.
 * http: fix typo in http.Request documentation (thanks Scott Lawrence)
         parse query string always, not just in GET
 * image/png: support 16-bit color.
 * io: ReadAtLeast now errors if min > len(buf).
 * jsonrpc: use `error: null` for success, not `error: ""`.
 * libmach: implement register fetch for 32-bit x86 kernel.
 * net: make IPv6 String method standards-compliant (thanks Mikio Hara).
 * os: FileInfo.Permission() now returns uint32 (thanks Scott Lawrence),
         implement env using native Windows API (thanks Alex Brainman).
 * reflect: allow PtrValue.PointTo(nil).
 * runtime: correct line numbers for .goc files,
         fix another stack split bug,
         fix freebsd/386 mmap.
 * syscall: regenerate syscall/z* files for linux/386, linux/amd64, linux/arm.
 * tabwriter: Introduce a new flag StripEscape.
 * template: fix handling of space around actions,
         vars preceded by white space parse correctly (thanks Roger Peppe).
 * test: add test case that crashes gccgo.
 * time: parse no longer requires minutes for time zone (thanks Jan H. Hosang)
 * yacc: fix bounds check in error recovery.
 </pre>

 <h2 id="2010-08-11">2010-08-11</h2>

 <pre>
 This release introduces some package changes. You may need to change your
 code if you use the once, regexp, image, or exp/draw packages.

 The type Once has been added to the sync package. The new sync.Once will
 supersede the functionality provided by the once package. We intend to remove
 the once package after this release. See:
     http://golang.org/pkg/sync/#Once
 All instances of once in the standard library have been replaced with
 sync.Once. Reviewing these changes may help you modify your existing code.
 The relevant changeset:
     http://code.google.com/p/go/source/detail?r=fa2c43595119

 A new set of methods has been added to the regular expression package, regexp.
 These provide a uniformly named approach to discovering the matches of an
 expression within a piece of text; see the package documentation for details:
     http://golang.org/pkg/regexp/
 These new methods will, in a later release, replace the old methods for
 matching substrings.  The following methods are deprecated:
     Execute (use FindSubmatchIndex)
     ExecuteString (use FindStringSubmatchIndex)
     MatchStrings(use FindStringSubmatch)
     MatchSlices (use FindSubmatch)
     AllMatches (use FindAll; note that n&lt;0 means 'all matches'; was n&lt;=0)
     AllMatchesString (use FindAllString; note that n&lt;0 means 'all matches'; was n&lt;=0)
 (Plus there are ten new methods you didn't know you wanted.)
 Please update your code to use the new routines before the next release.

 An image.Image now has a Bounds rectangle, where previously it ranged
 from (0, 0) to (Width, Height). Loops that previously looked like:
     for y := 0; y &lt; img.Height(); y++ {
         for x := 0; x &lt; img.Width(); x++ {
             // Do something with img.At(x, y)
         }
     }
 should instead be:
     b := img.Bounds()
     for y := b.Min.Y; y &lt; b.Max.Y; y++ {
         for x := b.Min.X; x &lt; b.Max.X; x++ {
             // Do something with img.At(x, y)
         }
     }
 The Point and Rectangle types have also moved from exp/draw to image.

 Other changes:
 * arm: bugfixes and syscall (thanks Kai Backman).
 * asn1: fix incorrect encoding of signed integers (thanks Nicholas Waples).
 * big: fixes to bitwise functions (thanks Evan Shaw).
 * bytes: add IndexRune, FieldsFunc and To*Special (thanks Christian Himpel).
 * encoding/binary: add complex (thanks Roger Peppe).
 * exp/iterable: add UintArray (thanks Anschel Schaffer-Cohen).
 * godoc: report Status 404 if a pkg or file is not found.
 * gofmt: better reporting for unexpected semicolon errors.
 * html: new package, an HTML tokenizer.
 * image: change image representation from slice-of-slices to linear buffer,
         introduce Decode and RegisterFormat,
         introduce Transparent and Opaque,
         replace Width and Height by Bounds, add the Point and Rect types.
 * libbio: fix Bprint to address 6g issues with large data structures.
 * math: fix amd64 Hypot (thanks Charles L. Dorian).
 * net/textproto: new package, with example net/dict.
 * os: fix ForkExec() handling of envv == nil (thanks Alex Brainman).
 * png: grayscale support (thanks Mathieu Lonjaret).
 * regexp: document that backslashes are the escape character.
 * rpc: catch errors from ReadResponseBody.
 * runtime: memory free fix (thanks Alex Brainman).
 * template: add ParseFile method to template.Template.
 * test/peano: use directly recursive type def.
 </pre>

 <h2 id="2010-08-04">2010-08-04</h2>

 <pre>
 This release includes a change to os.Open (and co.). The file permission
 argument has been changed to a uint32. Your code may require changes - a simple
 conversion operation at most.

 Other changes:
 * amd64: use segment memory for thread-local storage.
 * arm: add gdb support to android launcher script,
         bugfixes (stack clobbering, indices),
         disable another flaky test,
         remove old qemu dependency from gotest.
 * bufio: introduce Peek.
 * bytes: added test case for explode with blank string (thanks Scott Lawrence).
 * cgo: correct multiple return value function invocations (thanks Christian Himpel).
 * crypto/x509: unwrap Subject Key Identifier (thanks Adam Langley).
 * gc: index bounds tests and other fixes.
 * gofmt/go/parser: strengthen syntax checks.
 * goinstall: check for error from exec.*Cmd.Wait() (thanks Alex Brainman).
 * image/png: use image-specific methods for checking opacity.
 * image: introduce Gray and Gray16 types,
         remove the named colors except for Black and White.
 * json: object members must have a value (thanks Anthony Martin).
 * misc/vim: highlight misspelled words only in comments (thanks Christian Himpel).
 * os: Null device (thanks Peter Mundy).
 * runtime: do not fall through in SIGBUS/SIGSEGV.
 * strings: fix Split("", "", -1) (thanks Scott Lawrence).
 * syscall: make go errors not clash with windows errors (thanks Alex Brainman).
 * test/run: diff old new,
 * websocket: correct challenge response (thanks Tarmigan Casebolt),
         fix bug involving spaces in header keys (thanks Bill Neubauer).
 </pre>

 <h2 id="2010-07-29">2010-07-29</h2>

 <pre>
 * 5g: more soft float support and several bugfixes.
 * asn1: Enumerated, Flag and GeneralizedTime support.
 * build: clean.bash to check that GOOS and GOARCH are set.
 * bytes: add IndexFunc and LastIndexFunc (thanks Fazlul Shahriar),
 	add Title.
 * cgo: If CC is set in environment, use it rather than "gcc",
 	use new command line syntax: -- separates cgo flags from gcc flags.
 * codereview: avoid crash if no config,
 	don't run gofmt with an empty file list,
 	make 'hg submit' work with Mercurial 1.6.
 * crypto/ocsp: add package to parse OCSP responses.
 * crypto/tls: add client-side SNI support and PeerCertificates.
 * exp/bignum: delete package - functionality subsumed by package big.
 * fmt.Print: fix bug in placement of spaces introduced when ...T went in.
 * fmt.Scanf: handle trailing spaces.
 * gc: fix smaller-than-pointer-sized receivers in interfaces,
 	floating point precision/normalization fixes,
 	graceful exit on seg fault,
 	import dot shadowing bug,
 	many fixes including better handling of invalid input,
 	print error detail about failure to open import.
 * gccgo_install.html: add description of the port to RTEMS (thanks Vinu Rajashekhar).
 * gobs: fix bug in singleton arrays.
 * godoc: display synopses for all packages that have some kind of documentation..
 * gofmt: fix some linebreak issues.
 * http: add https client support (thanks Fazlul Shahriar),
 	write body when content length unknown (thanks James Whitehead).
 * io: MultiReader and MultiWriter (thanks Brad Fitzpatrick),
 	fix another race condition in Pipes.
 * ld: many fixes including better handling of invalid input.
 * libmach: correct handling of .5 files with D_REGREG addresses.
 * linux/386: use Xen-friendly ELF TLS instruction sequence.
 * mime: add AddExtensionType (thanks Yuusei Kuwana).
 * misc/vim: syntax file recognizes constants like 1e9 (thanks Petar Maymounkov).
 * net: TCPConn.SetNoDelay, back by popular demand.
 * net(windows): fix crashing Read/Write when passed empty slice on (thanks Alex Brainman),
 	implement LookupHost/Port/SRV (thanks Wei Guangjing),
 	properly handle EOF in (*netFD).Read() (thanks Alex Brainman).
 * runtime: fix bug introduced in revision 4a01b8d28570 (thanks Alex Brainman),
 	rename cgo2c, *.cgo to goc2c, *.goc (thanks Peter Mundy).
 * scanner: better comment.
 * strings: add Title.
 * syscall: add ForkExec, Syscall12 on Windows (thanks Daniel Theophanes),
 	improve windows errno handling (thanks Alex Brainman).
 * syscall(windows): fix FormatMessage (thanks Peter Mundy),
 	implement Pipe() (thanks Wei Guangjing).
 * time: fix parsing of minutes in time zones.
 * utf16(windows): fix cyclic dependency when testing (thanks Peter Mundy).
 </pre>

 <h2 id="2010-07-14">2010-07-14</h2>

 <pre>
 This release includes a package change. In container/vector, the Iter method
 has been removed from the Vector, IntVector, and StringVector types. Also, the
 Data method has been renamed to Copy to better express its actual behavior.
 Now that Vector is just a slice, any for loops ranging over v.Iter() or
 v.Data() can be changed to range over v instead.

 Other changes:
 * big: Improvements to Rat.SetString (thanks Evan Shaw),
         add sign, abs, Rat.IsInt.
 * cgo: various bug fixes.
 * codereview: Fix for Mercurial >= 1.6 (thanks Evan Shaw).
 * crypto/rand: add Windows implementation (thanks Peter Mundy).
 * crypto/tls: make HTTPS servers easier,
         add client OCSP stapling support.
 * exp/eval: converted from bignum to big (thanks Evan Shaw).
 * gc: implement new len spec, range bug fix, optimization.
 * go/parser: require that '...' parameters are followed by a type.
 * http: fix ParseURL to handle //relative_path properly.
 * io: fix SectionReader Seek to seek backwards (thanks Peter Mundy).
 * json: Add HTMLEscape (thanks Micah Stetson).
 * ld: bug fixes.
 * math: amd64 version of log (thanks Charles L. Dorian).
 * mime/multipart: new package to parse multipart MIME messages
         and HTTP multipart/form-data support.
 * os: use TempFile with default TempDir for test files (thanks Peter Mundy).
 * runtime/tiny: add docs for additional VMs, fix build (thanks Markus Duft).
 * runtime: better error for send/recv on nil channel.
 * spec: clarification of channel close(),
         lock down some details about channels and select,
         restrict when len(x) is constant,
         specify len/cap for nil slices, maps, and channels.
 * windows: append .exe to binary names (thanks Joe Poirier).
 </pre>

 <h2 id="2010-07-01">2010-07-01</h2>

 <pre>
 This release includes some package changes that may require changes to
 client code.

 The Split function in the bytes and strings packages has been changed.
 The count argument, which limits the size of the return, previously treated
 zero as unbounded. It now treats 0 as 0, and will return an empty slice.
 To request unbounded results, use -1 (or some other negative value).
 The new Replace functions in bytes and strings share this behavior.
 This may require you change your existing code.

 The gob package now allows the transmission of non-struct values at the
 top-level. As a result, the rpc and netchan packages have fewer restrictions
 on the types they can handle.  For example, netchan can now share a chan int.

 The release also includes a Code Walk: "Share Memory By Communicating".
 It describes an idiomatic Go program that uses goroutines and channels:
 	http://golang.org/doc/codewalk/sharemem/

 There is now a Projects page on the Go Dashboard that lists Go programs,
 tools, and libraries:
 	http://godashboard.appspot.com/project

 Other changes:
 * 6a, 6l: bug fixes.
 * bytes, strings: add Replace.
 * cgo: use slash-free relative paths for .so references.
 * cmath: correct IsNaN for argument cmplx(Inf, NaN) (thanks Charles L. Dorian).
 * codereview: allow multiple email addresses in CONTRIBUTORS.
 * doc/codewalk: add Share Memory By Communicating.
 * exp/draw/x11: implement the mapping from keycodes to keysyms.
 * fmt: Printf: fix bug in handling of %#v, allow other verbs for slices
         Scan: fix handling of EOFs.
 * gc: bug fixes and optimizations.
 * gob: add DecodeValue and EncodeValue,
         add support for complex numbers.
 * goinstall: support for Bazaar+Launchpad (thanks Gustavo Niemeyer).
 * io/ioutil: add TempFile for Windows (thanks Peter Mundy).
 * ld: add -u flag to check safe bits; discard old -u, -x flags.
 * math: amd64 versions of Exp and Fabs (thanks Charles L. Dorian).
 * misc/vim: always override filetype detection for .go files.
 * net: add support for DNS SRV requests (thanks Kirklin McDonald),
         initial attempt to implement Windows version (thanks Alex Brainman).
 * netchan: allow chan of basic types now that gob can handle such,
         eliminate the need for a pointer value in Import and Export.
 * os/signal: only catch all signals if os/signal package imported.
 * regexp: bug fix: need to track whether match begins with fixed prefix.
 * rpc: allow non-struct args and reply (they must still be pointers).
 * runtime: bug fixes and reorganization.
 * strconv: fix bugs in floating-point and base 2 conversions
 * syscall: add syscall_bsd.go to zsycall_freebsd_386.go (thanks Peter Mundy),
         add socketpair (thanks Ivan Krasin).
 * time: implement time zones for Windows (thanks Alex Brainman).
 * x509: support non-self-signed certs.
 </pre>

 <h2 id="2010-06-21">2010-06-21</h2>

 <pre>
 This release includes a language change. The "..." function parameter form is
 gone; "...T" remains. Typically, "...interface{}" can be used instead of "...".

 The implementation of Printf has changed in a way that subtly affects its
 handling of the fmt.Stringer interface. You may need to make changes to your
 code. For details, see:
         https://groups.google.com/group/golang-nuts/msg/6fffba90a3e3dc06

 The reflect package has been changed. If you have code that uses reflect,
 it will need to be updated. For details, see:
         https://groups.google.com/group/golang-nuts/msg/7a93d07c590e7beb

 Other changes:
 * 8l: correct test for sp == top of stack in 8l -K code.
 * asn1: allow '*' in PrintableString.
 * bytes.Buffer.ReadFrom: fix bug.
 * codereview: avoid exception in match (thanks Paolo Giarrusso).
 * complex divide: match C99 implementation.
 * exp/draw: small draw.drawGlyphOver optimization.
 * fmt: Print*: reimplement to switch on type first,
         Scanf: improve error message when input does not match format.
 * gc: better error messages for interface failures, conversions, undefined symbols.
 * go/scanner: report illegal escape sequences.
 * gob: substitute slice for map.
 * goinstall: process dependencies for package main (thanks Roger Peppe).
 * gopack: add S flag to force marking a package as safe,
         simplify go metadata code.
 * html: sync testdata/webkit to match WebKit tip.
 * http: reply to Expect 100-continue requests automatically (thanks Brad Fitzpatrick).
 * image: add an Alpha16 type.
 * ld: pad Go symbol table out to page boundary (fixes cgo crash).
 * misc/vim: reorganize plugin to be easier to use (thanks James Whitehead).
 * path: add Base, analogous to Unix basename.
 * pkg/Makefile: allow DISABLE_NET_TESTS=1 to disable network tests.
 * reflect: add Kind, Type.Bits, remove Int8Type, Int8Value, etc.
 * runtime: additional Windows support (thanks Alex Brainman),
         correct fault for 16-bit divide on Leopard,
         fix 386 signal handler bug.
 * strconv: add AtofN, FtoaN.
 * string: add IndexFunc and LastIndexFunc (thanks Roger Peppe).
 * syslog: use local network for tests.
 </pre>

 <h2 id="2010-06-09">2010-06-09</h2>

 <pre>
 This release contains many fixes and improvements, including several
 clarifications and consolidations to the Language Specification.

 The type checking rules around assignments and conversions are simpler but more
 restrictive: assignments no longer convert implicitly from *[10]int to []int
 (write x[0:] instead of &amp;x), and conversions can no longer change the names of
 types inside composite types.

 The fmt package now includes flexible type-driven (fmt.Scan) and
 format-driven (fmt.Scanf) scanners for all basic types.

 * big: bug fix for Quo aliasing problem.
 * bufio: change ReadSlice to match description.
 * cgo: bug fixes.
 * doc: add Google I/O talk and programs,
         codereview + Mercurial Queues info (thanks Peter Williams).
 * exp/draw: Draw fast paths for the Over operator,
         add Rectangle.Eq and Point.In, fix Rectangle.Clip (thanks Roger Peppe).
 * fmt: Scan fixes and improvements.
 * gc: backslash newline is not a legal escape sequence in strings,
         better error message when ~ operator is found,
         fix export of complex types,
         new typechecking rules.
 * go/parser: correct position of empty statement ';'.
 * gofmt: fix test script.
 * goinstall: use 'git pull' instead of 'git checkout' (thanks Michael Hoisie).
 * http: add Head function for making HTTP HEAD requests,
         handle status 304 correctly.
 * image: add Opaque method to the image types.
         make Color.RGBA return 16 bit color instead of 32 bit color.
 * io/ioutil: add TempFile.
 * math: Pow special cases and additional tests (thanks Charles L. Dorian).
 * netchan: improve closing and shutdown.
 * os: implement os.FileInfo.*time_ns for windows (thanks Alex Brainman).
 * os/signal: correct the regexp for finding Unix signal names (thanks Vinu Rajashekhar).
 * regexp: optimizations (thanks Kyle Consalus).
 * runtime: fix printing -Inf (thanks Evan Shaw),
         finish pchw -&gt; tiny, added gettime for tiny (thanks Daniel Theophanes).
 * spec: clean-ups and consolidation.
 * syscall: additional Windows compatibility fixes (thanks Alex Brainman).
 * test/bench: added regex-dna-parallel.go (thanks Kyle Consalus).
 * vector: type-specific Do functions now take f(type) (thanks Michael Hoisie).
 </pre>

 <h2 id="2010-05-27">2010-05-27</h2>

 <pre>
 A sizeable release, including standard library improvements and a slew of
 compiler bug fixes. The three-week interval was largely caused by the team
 preparing for Google I/O.

 * big: add Rat type (thanks Evan Shaw),
         new features, much performance tuning, cleanups, and more tests.
 * bignum: deprecate by moving into exp directory.
 * build: allow MAKEFLAGS to be set outside the build scripts (thanks Christopher Wedgwood).
 * bytes: add Trim, TrimLeft, TrimRight, and generic functions (thanks Michael Hoisie).
 * cgo: fix to permit cgo callbacks from init code.
 * cmath: update range of Phase and Polar due to signed zero (thanks Charles L. Dorian).
 * codereview: work better with mq (thanks Peter Williams).
 * compress: renamings
 	NewDeflater -&gt; NewWriter
 	NewInflater -&gt; NewReader
 	Deflater -&gt; Compressor
 	Inflater -&gt; Decompressor
 * exp/draw/x11: respect $XAUTHORITY,
         treat $DISPLAY the same way x-go-bindings does.
 * exp/draw: fast path for glyph images, other optimizations,
         fix Rectangle.Canon (thanks Roger Peppe).
 * fmt: Scan, Scanln: Start of a simple scanning API in the fmt package,
         fix Printf crash when given an extra nil argument (thanks Roger Peppe).
 * gc: better error when computing remainder of non-int (thanks Evan Shaw),
         disallow middot in Go programs,
         distinguish array, slice literal in error messages,
         fix shift/reduce conflict in go.y export syntax,
         fix unsafe.Sizeof on ideal constants,
         handle use of builtin function outside function call,
         many other bug fixes.
 * gob: add support for maps,
         add test for indirect maps, slices, arrays.
 * godoc: collect package comments from all package files.
 * gofmt: don't lose mandatory semicolons,
         exclude test w/ illegal syntax from test cases,
         fix printing of labels.
 * http: prevent crash if remote server is not responding with "HTTP/".
 * json: accept escaped slash in string scanner (thanks Michael Hoisie),
         fix array -&gt; non-array decoding.
 * libmach: skip __nl_symbol_ptr section on OS X.
 * math: amd64 versions of Fdim, Fmax, Fmin,
         signed zero Sqrt special case (thanks Charles L. Dorian).
 * misc/kate: convert isn't a built in function (thanks Evan Shaw).
 * net: implement BindToDevice,
         implement raw sockets (thanks Christopher Wedgwood).
 * netFD: fix race between Close and Read/Write (thanks Michael Hoisie).
 * os: add Chtimes function (thanks Brad Fitzpatrick).
 * pkg/Makefile: add netchan to standard package list.
 * runtime: GOMAXPROCS returns previous value,
         allow large map values,
         avoid allocation for fixed strings,
         correct tracebacks for nascent goroutines, even closures,
         free old hashmap pieces during resizing.
 * spec: added imaginary literal to semicolon rules (was missing),
         fix and clarify syntax of conversions,
         simplify section on channel types,
         other minor tweaks.
 * strconv: Btoui64 optimizations (thanks Kyle Consalus).
 * strings: use copy instead of for loop in Map (thanks Kyle Consalus).
 * syscall: implement BindToDevice (thanks Christopher Wedgwood),
         add Utimes on Darwin/FreeBSD, add Futimes everywhere,
         regenerate syscalls for some platforms.
 * template: regularize name lookups of interfaces, pointers, and methods.
 </pre>

 <h2 id="2010-05-04">2010-05-04</h2>

 <pre>
 In this release we renamed the Windows OS target from 'mingw' to 'windows'.
 If you are currently building for 'mingw' you should set GOOS=windows instead.

 * 5l, 6l, 8l, runtime: make -s binaries work.
 * 5l, 6l, 8l: change ELF header so that strip doesn't destroy binary.
 * 8l: fix absolute path detection on Windows.
 * big: new functions, optimizations, and cleanups,
 	add bitwise methods for Int (thanks Evan Shaw).
 * bytes: Change IndexAny to look for UTF-8 encoded characters.
 * darwin: bsdthread_create can fail; print good error.
 * fmt: %T missing print &lt;nil&gt; for nil (thanks Christopher Wedgwood).
 * gc: many fixes.
 * misc/cgo/gmp: fix bug in SetString.
 * net: fix resolv.conf EOF without newline bug (thanks Christopher Wedgwood).
 * spec: some small clarifications (no language changes).
 * syscall: add EWOULDBLOCK to sycall_nacl.go,
 	force O_LARGEFILE in Linux open system call,
 	handle EOF on pipe - special case on Windows (thanks Alex Brainman),
 	mingw Sleep (thanks Joe Poirier).
 * test/bench: import new fasta C reference, update Go, optimizations.
 * test: test of static initialization (fails).
 * vector: use correct capacity in call to make.
 * xml: allow text segments to end at EOF.
 </pre>

 <h2 id="2010-04-27">2010-04-27</h2>

 <pre>
 This release includes a new Codelab that illustrates the construction of a
 simple wiki web application:
 	http://golang.org/doc/codelab/wiki/

 It also includes a Codewalk framework for documenting code. See:
 	http://golang.org/doc/codewalk/

 Other changes:
 * 6g: fix need for parens around array index expression.
 * 6l, 8l: include ELF header in PT_LOAD mapping for text segment.
 * arm: add android runner script,
 	support for printing floats.
 * big: implemented Karatsuba multiplication,
 	many fixes and improvements (thanks Evan Shaw).
 * bytes: add Next method to Buffer, simplify Read,
 	shuffle implementation, making WriteByte 50% faster.
 * crypto/tls: simpler implementation of record layer.
 * exp/eval: fixes (thanks Evan Shaw).
 * flag: eliminate unnecessary structs.
 * gc: better windows support,
 	cmplx typecheck bug fix,
 	more specific error for statements at top level.
 * go/parser: don't require unnecessary parens.
 * godoc: exclude duplicate entries (thanks Andrei Vieru),
 	use int64 for timestamps (thanks Christopher Wedgwood).
 * gofmt: fine-tune stripping of parentheses,
 * json: Marshal, Unmarshal using new scanner,
 	preserve field name case by default,
 	scanner, Compact, Indent, and tests,
 	support for streaming.
 * libmach: disassemble MOVLQZX correctly.
 * math: more special cases for signed zero (thanks Charles L. Dorian).
 * net: add Pipe,
 	fix bugs in packStructValue (thanks Michael Hoisie),
 	introduce net.Error interface.
 * os: FileInfo: regularize the types of some fields,
 	create sys_bsd.go (thanks Giles Lean),
 	mingw bug fixes (thanks Alex Brainman).
 * reflect: add FieldByNameFunc (thanks Raif S. Naffah),
 	implement Set(nil), SetValue(nil) for PtrValue and MapValue.
 * regexp: allow escaping of any punctuation.
 * rpc/jsonrpc: support for jsonrpc wire encoding.
 * rpc: abstract client and server encodings,
 	add Close() method to rpc.Client.
 * runtime: closures, defer bug fix for Native Client,
 	rename cgo2c, *.cgo to goc2c, *.goc to avoid confusion with real cgo.
 	several other fixes.
 * scanner: implement Peek() to look at the next char w/o advancing.
 * strings: add ReadRune to Reader, add FieldsFunc (thanks Kyle Consalus).
 * syscall: match linux Setsid function signature to darwin,
 	mingw bug fixes (thanks Alex Brainman).
 * template: fix handling of pointer inside interface.
 * test/bench: add fannkuch-parallel.go (thanks Kyle Consalus),
 	pidigits ~10% performance win by using adds instead of shifts.
 * time: remove incorrect time.ISO8601 and add time.RFC3339 (thanks Micah Stetson).
 * utf16: add DecodeRune, EncodeRune.
 * xml: add support for XML marshalling embedded structs (thanks Raif S. Naffah),
 	new "innerxml" tag to collect inner XML.
 </pre>

 <h2 id="2010-04-13">2010-04-13</h2>

 <pre>
 This release contains many changes:

 * 8l: add DOS stub to PE binaries (thanks Evan Shaw).
 * cgo: add //export.
 * cmath: new complex math library (thanks Charles L. Dorian).
 * docs: update to match current coding style (thanks Christopher Wedgwood).
 * exp/eval: fix example and add target to Makefile (thanks Evan Shaw).
 * fmt: change behaviour of format verb %b to match %x when negative (thanks Andrei Vieru).
 * gc: compile s == "" as len(s) == 0,
 	distinguish fatal compiler bug from error+exit,
 	fix alignment on non-amd64,
 	good syntax error for defer func() {} - missing fina (),
 	implement panic and recover,
 	zero unnamed return values on entry if func has defer.
 * goyacc: change to be reentrant (thanks Roger Peppe).
 * io/ioutil: fix bug in ReadFile when Open succeeds but Stat fails.
 * kate: update for recent language changes (thanks Evan Shaw).
 * libcgo: initial mingw port work - builds but untested (thanks Joe Poirier).
 * math: new functions and special cases (thanks Charles L. Dorian)
 * net: use chan bool instead of chan *netFD to avoid cycle.
 * netchan: allow client to send as well as receive.
 * nntp: new package, NNTP client (thanks Conrad Meyer).
 * os: rename os.Dir to os.FileInfo.
 * rpc: don't log normal EOF,
 	fix ServeConn to block as documented.
 * runtime: many bug fixes, better ARM support.
 * strings: add IndexRune, Trim, TrimLeft, TrimRight, etc (thanks Michael Hoisie).
 * syscall: implement some mingw syscalls required by os (thanks Alex Brainman).
 * test/bench: add k-nucleotide-parallel (thanks Kyle Consalus).
 * Unicode: add support for Turkish case mapping.
 * xgb: move from the main repository to http://code.google.com/p/x-go-binding/
 </pre>

 <h2 id="2010-03-30">2010-03-30</h2>

 <pre>
 This release contains three language changes:

 1. Accessing a non-existent key in a map is no longer a run-time error.
 It now evaluates to the zero value for that type.  For example:
         x := myMap[i]   is now equivalent to:   x, _ := myMap[i]

 2. It is now legal to take the address of a function's return value.
 The return values are copied back to the caller only after deferred
 functions have run.

 3. The functions panic and recover, intended for reporting and recovering from
 failure, have been added to the spec:
 	http://golang.org/doc/go_spec.html#Handling_panics
 In a related change, panicln is gone, and panic is now a single-argument
 function.  Panic and recover are recognized by the gc compilers but the new
 behavior is not yet implemented.

 The ARM build is broken in this release; ARM users should stay at release.2010-03-22.

 Other changes:
 * bytes, strings: add IndexAny.
 * cc/ld: Add support for #pragma dynexport,
         Rename dynld to dynimport throughout. Cgo users will need to rerun cgo.
 * expvar: default publishings for cmdline, memstats
 * flag: add user-defined flag types.
 * gc: usual bug fixes
 * go/ast: generalized ast filtering.
 * go/printer: avoid reflect in print.
 * godefs: fix handling of negative constants.
 * godoc: export pprof debug information, exported variables,
         support for filtering of command-line output in -src mode,
         use http GET for remote search instead of rpc.
 * gofmt: don't convert multi-line functions into one-liners,
         preserve newlines in multiline selector expressions (thanks Risto Jaakko Saarelma).
 * goinstall: include command name in error reporting (thanks Andrey Mirtchovski)
 * http: add HandleFunc as shortcut to Handle(path, HandlerFunc(func))
 * make: use actual dependency for install
 * math: add J1, Y1, Jn, Yn, J0, Y0 (Bessel functions) (thanks Charles L. Dorian)
 * prof: add pprof from google-perftools
 * regexp: don't return non-nil *Regexp if there is an error.
 * runtime: add Callers,
         add malloc sampling, pprof interface,
         add memory profiling, more statistics to runtime.MemStats,
         implement missing destroylock() (thanks Alex Brainman),
         more malloc statistics,
         run all finalizers in a single goroutine,
         Goexit runs deferred calls.
 * strconv: add Atob and Btoa,
         Unquote could wrongly return a nil error on error (thanks Roger Peppe).
 * syscall: add IPV6 constants,
         add syscall_bsd.go for Darwin and other *BSDs (thanks Giles Lean),
         implement SetsockoptString (thanks Christopher Wedgwood).
 * websocket: implement new protocol (thanks Fumitoshi Ukai).
 * xgb: fix request length and request size (thanks Firmansyah Adiputra).
 * xml: add CopyToken (thanks Kyle Consalus),
         add line numbers to syntax errors (thanks Kyle Consalus),
         use io.ReadByter in place of local readByter (thanks Raif S. Naffah).
 </pre>

 <h2 id="2010-03-22">2010-03-22</h2>

 <pre>
 With this release we announce the launch of the Go Blog:
 	http://blog.golang.org/
 The first post is a brief update covering what has happened since the launch.

 This release contains some new packages and functionality, and many fixes:
 * 6g/8g: fix issues with complex data types, other bug fixes.
 * Makefiles: refactored to make writing external Makefiles easier.
 * crypto/rand: new package.
 * godoc: implemented command-line search via RPC,
 	improved comment formatting: recognize URLs.
 * gofmt: more consistent formatting of const/var decls.
 * http: add Error helper function,
 	add ParseQuery (thanks Petar Maymounkov),
 	change RawPath to mean raw path, not raw everything-after-scheme.
 * image/jpeg: fix typos.
 * json: add MarshalIndent (accepts user-specified indent string).
 * math: add Gamma function (thanks Charles L. Dorian).
 * misc/bbedit: support for cmplx, real, imag (thanks Anthony Starks).
 * misc/vim: add new complex types, functions and literals.
 * net: fix IPMask.String not to crash on all-0xff mask.
 * os: drop File finalizer after normal Close.
 * runtime: add GOROOT and Version,
 	lock finalizer table accesses.
 * sha512: add sha384 (truncated version) (thanks Conrad Meyer).
 * syscall: add const ARCH, analogous to OS.
 * syscall: further additions to mingw port (thanks Alex Brainman).
 * template: fixed html formatter []byte input bug.
 * utf16: new package.
 * version.bash: cope with ancient Mercurial.
 * websocket: use URL.RawPath to construct WebSocket-Location: header.
 </pre>

 <h2 id="2010-03-15">2010-03-15</h2>

 <pre>
 This release includes a language change: support for complex numbers.
 	http://golang.org/doc/go_spec.html#Imaginary_literals
 	http://golang.org/doc/go_spec.html#Complex_numbers
 There is no library support as yet.

 This release also includes the goinstall command-line tool.
 	http://golang.org/cmd/goinstall/
 	http://groups.google.com/group/golang-nuts/t/f091704771128e32

 * 5g/6g/8g: fix double function call in slice.
 * arm: cleanup build warnings. (thanks Dean Prichard)
 * big: fix mistakes with probablyPrime.
 * bufio: add WriteRune.
 * bytes: add ReadRune and WriteRune to bytes.Buffer.
 * cc: stack split bug fix.
 * crypto: add SHA-224 to sha256, add sha512 package. (thanks Conrad Meyer)
 * crypto/ripemd160: new package. (thanks Raif S. Naffah)
 * crypto/rsa: don't use safe primes.
 * gc: avoid fixed length buffer cleanbuf. (thanks Dean Prichard)
 	better compilation of floating point +=
 	fix crash on complicated arg to make slice.
 	remove duplicate errors, give better error for I.(T)
 * godoc: support for multiple packages in a directory, other fixes.
 * gofmt: bug fixes.
 * hash: add Sum64 interface.
 * hash/crc32: add Update function.
 * hash/crc64: new package implementing 64-bit CRC.
 * math: add ilogb, logb, remainder. (thanks Charles L. Dorian)
 * regexp: add ReplaceAllFunc, ReplaceAllStringFunc.
 * runtime: clock garbage collection on bytes allocated, not pages in use.
 * strings: make Split(s, "", n) faster. (thanks Spring Mc)
 * syscall: minimal mingw version of syscall. (thanks Alex Brainman)
 * template: add ParseFile, MustParseFile.
 </pre>

 <h2 id="2010-03-04">2010-03-04</h2>

 <pre>
 There is one language change: the ability to convert a string to []byte or
 []int.  This deprecates the strings.Bytes and strings.Runes functions.
 You can convert your existing sources using these gofmt commands:
 	gofmt -r 'strings.Bytes(x) -&gt; []byte(x)' -w file-or-directory-list
 	gofmt -r 'strings.Runes(x) -&gt; []int(x)' -w file-or-directory-list
 After running these you might need to delete unused imports of the "strings"
 package.

 Other changes and fixes:
 * 6l/8l/5l: add -r option
 * 8g: make a[byte(x)] truncate x
 * codereview.py: fix for compatibility with hg >=1.4.3
 * crypto/blowfish: new package (thanks Raif S. Naffah)
 * dashboard: more performance tuning
 * fmt: use String method in %q to get the value to quote.
 * gofmt: several cosmetic changes
 * http: fix handling of Connection: close, bug in http.Post
 * net: correct DNS configuration,
 	fix network timeout boundary condition,
 	put [ ] around IPv6 addresses for Dial.
 * path: add Match,
 	fix bug in Match with non-greedy stars (thanks Kevin Ballard)
 * strings: delete Bytes, Runes (see above)
 * tests: an Eratosthenesque concurrent prime sieve (thanks Anh Hai Trinh)
 </pre>

 <h2 id="2010-02-23">2010-02-23</h2>

 <pre>
 This release is mainly bug fixes and a little new code.
 There are no language changes.

 6g/5g/8g: bug fixes
 8a/8l: Added FCMOVcc instructions (thanks Evan Shaw and Charles Dorian)
 crypto/x509: support certificate creation
 dashboard: caching to avoid datastore queries
 exec: add dir argument to Run
 godoc: bug fixes and code cleanups
 http: continued implementation and bug fixes (thanks Petar Maymounkov)
 json: fix quoted strings in Marshal (thanks Sergei Skorobogatov)
 math: more functions, test cases, and benchmarks (thanks Charles L. Dorian)
 misc/bbedit: treat predeclared identifiers as "keywords" (thanks Anthony Starks)
 net: disable UDP server test (flaky on various architectures)
 runtime: work around Linux kernel bug in futex,
 	pchw is now tiny
 sync: fix to work on armv5 (thanks Dean Prichard)
 websocket: fix binary frame size decoding (thanks Timo Savola)
 xml: allow unquoted attribute values in non-Strict mode (thanks Amrut Joshi)
 	treat bool as value in Unmarshal (thanks Michael Hoisie)
 </pre>

 <h2 id="2010-02-17">2010-02-17</h2>

 <pre>
 There are two small language changes:
 * NUL bytes may be rejected in souce files, and the tools do reject them.
 * Conversions from string to []int and []byte are defined but not yet implemented.

 Other changes and fixes:
 * 5a/6a/8a/5c/6c/8c: remove fixed-size arrays for -I and -D options (thanks Dean Prichard)
 * 5c/6c/8c/5l/6l/8l: add -V flag to display version number
 * 5c/6c/8c: use "cpp" not "/bin/cpp" for external preprocessor (thanks Giles Lean)
 * 8a/8l: Added CMOVcc instructions (thanks Evan Shaw)
 * 8l: pe executable building code changed to include import table for kernel32.dll functions (thanks Alex Brainman)
 * 5g/6g/8g: bug fixes
 * asn1: bug fixes and additions (incl marshalling)
 * build: fix build for Native Client, Linux/ARM
 * dashboard: show benchmarks, add garbage collector benchmarks
 * encoding/pem: add marshalling support
 * exp/draw: fast paths for a nil mask
 * godoc: support for directories outside $GOROOT
 * http: sort header keys when writing Response or Request to wire (thanks Petar Maymounkov)
 * math: special cases and new functions (thanks Charles Dorian)
 * mime: new package, used in http (thanks Michael Hoisie)
 * net: dns bug fix - use random request id
 * os: finalize File, to close fd.
 * path: make Join variadic (thanks Stephen Weinberg)
 * regexp: optimization bug fix
 * runtime: misc fixes and optimizations
 * syscall: make signature of Umask on OS X, FreeBSD match Linux. (thanks Giles Lean)
 </pre>

 <h2 id="2010-02-04">2010-02-04</h2>

 <pre>
 There is one language change: support for ...T parameters:
 	http://golang.org/doc/go_spec.html#Function_types

 You can now check build status on various platforms at the Go Dashboard:
 	http://godashboard.appspot.com

 * 5l/6l/8l: several minor fixes
 * 5a/6a/8a/5l/6l/8l: avoid overflow of symb buffer (thanks Dean Prichard)
 * compress/gzip: gzip deflater (i.e., writer)
 * debug/proc: add mingw specific build stubs (thanks Joe Poirier)
 * exp/draw: separate the source-point and mask-point in Draw
 * fmt: handle nils safely in Printf
 * gccgo: error messages now match those of gc
 * godoc: several fixes
 * http: bug fixes, revision of Request/Response (thanks Petar Maymounkov)
 * image: new image.A type to represent anti-aliased font glyphs
 	add named colors (e.g. image.Blue), suitable for exp/draw
 * io: fixed bugs in Pipe
 * malloc: merge into package runtime
 * math: fix tests on FreeBSD (thanks Devon H. O'Dell)
 	add functions; update tests and special cases (thanks Charles L. Dorian)
 * os/signal: send SIGCHLDs to Incoming (thanks Chris Wedgwood)
 * reflect: add StringHeader to reflect
 * runtime: add SetFinalizer
 * time: Sleep through interruptions (thanks Chris Wedgwood)
 	add RFC822 formats
 	experimental implemenation of Ticker using two goroutines for all tickers
 * xml: allow underscores in XML element names (thanks Michael Hoisie)
 	allow any scalar type in xml.Unmarshal
 </pre>

 <h2 id="2010-01-27">2010-01-27</h2>

 <pre>
 There are two small language changes: the meaning of chan &lt;- chan int
 is now defined, and functions returning functions do not need to
 parenthesize the result type.

 There is one significant implementation change: the compilers can
 handle multiple packages using the same name in a single binary.
 In the gc compilers, this comes at the cost of ensuring that you
 always import a particular package using a consistent import path.
 In the gccgo compiler, the cost is that you must use the -fgo-prefix
 flag to pass a unique prefix (like the eventual import path).

 5a/6a/8a: avoid use of fixed-size buffers (thanks Dean Prichard)
 5g, 6g, 8g: many minor bug fixes
 bufio: give Writer.WriteString same signature as bytes.Buffer.WriteString.
 container/list: PushFrontList, PushBackList (thanks Jan Hosang)
 godoc: trim spaces from search query (thanks Christopher Wedgwood)
 hash: document that Sum does not change state, fix crypto hashes
 http: bug fixes, revision of Request/Response (thanks Petar Maymounkov)
 math: more handling of IEEE 754 special cases (thanks Charles Dorian)
 misc/dashboard: new build dashboard
 net: allow UDP broadcast,
 	use /etc/hosts to resolve names (thanks Yves Junqueira, Michael Hoisie)
 netchan: beginnings of new package for connecting channels across a network
 os: allow FQDN in Hostname test (thanks Icarus Sparry)
 reflect: garbage collection bug in Call
 runtime: demo of Go on raw (emulated) hw in runtime/pchw,
 	performance fix on OS X
 spec: clarify meaning of chan &lt;- chan int,
 	func() func() int is allowed now,
 	define ... T (not yet implemented)
 template: can use interface values
 time: fix for +0000 time zone,
 	more robust tick.Stop.
 xgb: support for authenticated connections (thanks Firmansyah Adiputra)
 xml: add Escape (thanks Stephen Weinberg)
 </pre>

 <h2 id="2010-01-13">2010-01-13</h2>

 <pre>
 This release is mainly bug fixes with a little new code.
 There are no language changes.

 build: $GOBIN should no longer be required in $PATH (thanks Devon H. O'Dell),
 	new package target "make bench" to run benchmarks
 8g: faster float -&gt; uint64 conversion (thanks Evan Shaw)
 5g, 6g, 8g:
 	clean opnames.h to avoid stale errors (thanks Yongjian Xu),
 	a handful of small compiler fixes
 5g, 6g, 8g, 5l, 6l, 8l: ignore $GOARCH, which is implied by name of tool
 6prof: support for writing input files for google-perftools's pprof
 asn1: fix a few structure-handling bugs
 cgo: many bug fixes (thanks Devon H. O'Dell)
 codereview: repeated "hg mail" sends "please take another look"
 gob: reserve ids for future expansion
 godoc: distinguish HTML generation from plain text HTML escaping (thanks Roger Peppe)
 gofmt: minor bug fixes, removed -oldprinter flag
 http: add CanonicalPath (thanks Ivan Krasin),
 	avoid header duplication in Response.Write,
 	correctly escape/unescape URL sections
 io: new interface ReadByter
 json: better error, pointer handling in Marshal (thanks Ivan Krasin)
 libmach: disassembly of FUCOMI, etc (thanks Evan Shaw)
 math: special cases for most functions and 386 hardware Sqrt (thanks Charles Dorian)
 misc/dashboard: beginning of a build dashboard at godashboard.appspot.com.
 misc/emacs: handling of new semicolon rules (thanks Austin Clements),
 	empty buffer bug fix (thanks Kevin Ballard)
 misc/kate: highlighting improvements (tahnks Evan Shaw)
 os/signal: add signal names: signal.SIGHUP, etc (thanks David Symonds)
 runtime: preliminary Windows support (thanks Hector Chu),
 	preemption polling to reduce garbage collector pauses
 scanner: new lightweight scanner package
 template: bug fix involving spaces before a delimited block
 test/bench: updated timings
 time: new Format, Parse functions
 </pre>

 <h2 id="2010-01-05">2010-01-05</h2>

 <pre>
 This release is mainly bug fixes.  There are no language changes.

 6prof: now works on 386
 8a, 8l: add FCOMI, FCOMIP, FUCOMI, and FUCOMIP (thanks Evan Shaw)
 big: fix ProbablyPrime on small numbers
 container/vector: faster []-based implementation (thanks Jan Mercl)
 crypto/tls: extensions and Next Protocol Negotiation
 gob: one encoding bug fix, one decoding bug fix
 image/jpeg: support for RST markers
 image/png: support for transparent paletted images
 misc/xcode: improved support (thanks Ken Friedenbach)
 net: return nil Conn on error from Dial (thanks Roger Peppe)
 regexp: add Regexp.NumSubexp (thanks Peter Froehlich)
 syscall: add Nanosleep on FreeBSD (thanks Devon H. O'Dell)
 template: can use map in .repeated section

 There is now a public road map, in the repository and online
 at <a href="http://golang.org/doc/devel/roadmap.html">http://golang.org/doc/devel/roadmap.html</a>.
 </pre>

 <h2 id="2009-12-22">2009-12-22</h2>

 <pre>
 Since the last release there has been one large syntactic change to
 the language, already discussed extensively on this list: semicolons
 are now implied between statement-ending tokens and newline characters.
 See http://groups.google.com/group/golang-nuts/t/5ee32b588d10f2e9 for
 details.

 By default, gofmt now parses and prints the new lighter weight syntax.
 To convert programs written in the old syntax, you can use:

 	gofmt -oldparser -w *.go

 Since everything was being reformatted anyway, we took the opportunity to
 change the way gofmt does alignment.  Now gofmt uses tabs at the start
 of a line for basic code alignment, but it uses spaces for alignment of
 interior columns.  Thus, in an editor with a fixed-width font, you can
 choose your own tab size to change the indentation, and no matter what
 tab size you choose, columns will be aligned properly.


 In addition to the syntax and formatting changes, there have been many
 smaller fixes and updates:

 6g,8g,5g: many bug fixes, better registerization,
    build process fix involving mkbuiltin (thanks Yongjian Xu),
    method expressions for concrete types
 8l: support for Windows PE files (thanks Hector Chu)
 bytes: more efficient Buffer handling
 bytes, strings: new function Fields (thanks Andrey Mirtchovski)
 cgo: handling of enums (thanks Moriyoshi Koizumi),
     handling of structs with bit fields, multiple files (thanks Devon H. O'Dell),
     installation of .so to non-standard locations
 crypto/sha256: new package for SHA 256 (thanks Andy Davis)
 encoding/binary: support for slices of fixed-size values (thanks Maxim Ushakov)
 exp/vector: experimental alternate vector representation (thanks Jan Mercl)
 fmt: %p for chan, map, slice types
 gob: a couple more bug fixes
 http: support for basic authentication (thanks Ivan Krasin)
 image/jpeg: basic JPEG decoder
 math: correct handling of Inf and NaN in Pow (thanks Charles Dorian)
 misc/bash: completion file for bash (thanks Alex Ray)
 os/signal: support for handling Unix signals (thanks David Symonds)
 rand: Zipf-distributed random values (thanks William Josephson)
 syscall: correct error return bug on 32-bit machines (thanks Christopher Wedgwood)
 syslog: new package for writing to Unix syslog daemon (thanks Yves Junqueira)
 template: will automatically invoke niladic methods
 time: new ISO8601 format generator (thanks Ben Olive)
 xgb: converted generator to new syntax (thanks Tor Andersson)
 xml: better mapping of tag names to Go identifiers (thanks Kei Son),
     better handling of unexpected EOF (thanks Arvindh Rajesh Tamilmani)
 </pre>

 <h2 id="2009-12-09">2009-12-09</h2>

 <pre>
 Since the last release there are two changes to the language:

 * new builtin copy(dst, src) copies n = min(len(dst), len(src))
   elements to dst from src and returns n.  It works correctly
   even if dst and src overlap.  bytes.Copy is gone.
   Convert your programs using:
       gofmt -w -r 'bytes.Copy(d, s) -&gt; copy(d, s)' *.go

 * new syntax x[lo:] is shorthand for x[lo:len(x)].
   Convert your programs using:
       gofmt -w -r 'a[b:len(a)] -&gt; a[b:]' *.go

 In addition, there have been many smaller fixes and updates:

 * 6g/8g/5g: many bug fixes
 * 8g: fix 386 floating point stack bug (thanks Charles Dorian)
 * all.bash: now works even when $GOROOT has spaces (thanks Sergio Luis O. B. Correia),
     starting to make build work with mingw (thanks Hector Chu),
     FreeBSD support (thanks Devon O'Dell)
 * big: much faster on 386.
 * bytes: new function IndexByte, implemented in assembly
     new function Runes (thanks Peter Froehlich),
     performance tuning in bytes.Buffer.
 * codereview: various bugs fixed
 * container/vector: New is gone; just declare a Vector instead.
     call Resize to set len and cap.
 * cgo: many bug fixes (thanks Eden Li)
 * crypto: added MD4 (thanks Chris Lennert),
     added XTEA (thanks Adrian O'Grady).
 * crypto/tls: basic client
 * exp/iterable: new functions (thanks Michael Elkins)
 * exp/nacl: native client tree builds again
 * fmt: preliminary performance tuning
 * go/ast: more powerful Visitor (thanks Roger Peppe)
 * gob: a few bug fixes
 * gofmt: better handling of standard input, error reporting (thanks Fazlul Shahriar)
     new -r flag for rewriting programs
 * gotest: support for Benchmark functions (thanks Trevor Strohman)
 * io: ReadFile, WriteFile, ReadDir now in separate package io/ioutil.
 * json: new Marshal function (thanks Michael Hoisie),
     better white space handling (thanks Andrew Skiba),
     decoding into native data structures (thanks Sergey Gromov),
     handling of nil interface values (thanks Ross Light).
 * math: correct handling of sin/cos of large angles
 * net: better handling of Close (thanks Devon O'Dell and Christopher Wedgwood)
     support for UDP broadcast (thanks Jonathan Wills),
     support for empty packets
 * rand: top-level functions now safe to call from multiple goroutines
 (thanks Roger Peppe).
 * regexp: a few easy optimizations
 * rpc: better error handling, a few bug fixes
 * runtime: better signal handling on OS X, malloc fixes,
     global channel lock is gone.
 * sync: RWMutex now allows concurrent readers (thanks Péter Szabó)
 * template: can use maps as data (thanks James Meneghello)
 * unicode: updated to Unicode 5.2.
 * websocket: new package (thanks Fumitoshi Ukai)
 * xgb: preliminary X Go Bindings (thanks Tor Andersson)
 * xml: fixed crash (thanks Vish Subramanian)
 * misc: bbedit config (thanks Anthony Starks),
     kate config (thanks Evan Shaw)
 </pre>