testing: eliminate testing/regexp
Rather than updating the stripped-down regexp implementation embedded
in testing, delete it by passing the one function we need from the package
main file created by gotest.

R=rsc
CC=golang-dev
https://golang.org/cl/2761043
diff --git a/src/cmd/gotest/gotest b/src/cmd/gotest/gotest
index 32b4aa5..7a7e225 100755
--- a/src/cmd/gotest/gotest
+++ b/src/cmd/gotest/gotest
@@ -147,6 +147,7 @@
 		echo 'import "./_xtest_"'
 	fi
 	echo 'import "testing"'
+	echo 'import __regexp__ "regexp"' # rename in case tested package is called regexp
 	# test array
 	echo
 	echo 'var tests = []testing.Test{'
@@ -166,8 +167,8 @@
 	# body
 	echo
 	echo 'func main() {'
-	echo '	testing.Main(tests)'
-	echo '	testing.RunBenchmarks(benchmarks)'
+	echo '	testing.Main(__regexp__.MatchString, tests)'
+	echo '	testing.RunBenchmarks(__regexp__.MatchString, benchmarks)'
 	echo '}'
 }>_testmain.go
 
diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index 0bd56764..d2e665f 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -151,6 +151,7 @@
 	rand\
 	runtime/pprof\
 	syscall\
+	testing\
 	testing/iotest\
 	try\
 	../libcgo\
diff --git a/src/pkg/exp/eval/eval_test.go b/src/pkg/exp/eval/eval_test.go
index 4de4fb2..d78242d 100644
--- a/src/pkg/exp/eval/eval_test.go
+++ b/src/pkg/exp/eval/eval_test.go
@@ -11,6 +11,7 @@
 	"log"
 	"os"
 	"reflect"
+	"regexp"
 	"testing"
 )
 
@@ -89,9 +90,9 @@
 }
 
 func match(t *testing.T, err os.Error, pat string) bool {
-	ok, errstr := testing.MatchString(pat, err.String())
-	if errstr != "" {
-		t.Fatalf("compile regexp %s: %v", pat, errstr)
+	ok, err1 := regexp.MatchString(pat, err.String())
+	if err1 != nil {
+		t.Fatalf("compile regexp %s: %v", pat, err1)
 	}
 	return ok
 }
diff --git a/src/pkg/fmt/scan_test.go b/src/pkg/fmt/scan_test.go
index 23c7d29..9193932 100644
--- a/src/pkg/fmt/scan_test.go
+++ b/src/pkg/fmt/scan_test.go
@@ -10,6 +10,7 @@
 	"io"
 	"os"
 	"reflect"
+	"regexp"
 	"strings"
 	"testing"
 	"utf8"
@@ -101,7 +102,7 @@
 	if err != nil {
 		return err
 	}
-	if !testing.MustCompile("^" + string(verb) + "+$").MatchString(tok) {
+	if !regexp.MustCompile("^" + string(verb) + "+$").MatchString(tok) {
 		return os.ErrorString("syntax error for xs")
 	}
 	*x = Xs(tok)
@@ -385,7 +386,7 @@
 
 func TestScanOverflow(t *testing.T) {
 	// different machines and different types report errors with different strings.
-	re := testing.MustCompile("overflow|too large|out of range|not representable")
+	re := regexp.MustCompile("overflow|too large|out of range|not representable")
 	for _, test := range overflowTests {
 		_, err := Sscan(test.text, test.in)
 		if err == nil {
diff --git a/src/pkg/io/ioutil/tempfile_test.go b/src/pkg/io/ioutil/tempfile_test.go
index fe43f95..d949a86 100644
--- a/src/pkg/io/ioutil/tempfile_test.go
+++ b/src/pkg/io/ioutil/tempfile_test.go
@@ -23,7 +23,7 @@
 		t.Errorf("TempFile(dir, `ioutil_test`) = %v, %v", f, err)
 	}
 	if f != nil {
-		re := testing.MustCompile("^" + regexp.QuoteMeta(dir) + "/ioutil_test[0-9]+$")
+		re := regexp.MustCompile("^" + regexp.QuoteMeta(dir) + "/ioutil_test[0-9]+$")
 		if !re.MatchString(f.Name()) {
 			t.Errorf("TempFile(`"+dir+"`, `ioutil_test`) created bad name %s", f.Name())
 		}
diff --git a/src/pkg/testing/Makefile b/src/pkg/testing/Makefile
index 19b791a..9e8bd17 100644
--- a/src/pkg/testing/Makefile
+++ b/src/pkg/testing/Makefile
@@ -7,7 +7,6 @@
 TARG=testing
 GOFILES=\
         benchmark.go\
-	regexp.go\
 	testing.go\
 
 include ../../Make.pkg
diff --git a/src/pkg/testing/benchmark.go b/src/pkg/testing/benchmark.go
index 6266de9..bdec302 100644
--- a/src/pkg/testing/benchmark.go
+++ b/src/pkg/testing/benchmark.go
@@ -148,18 +148,18 @@
 
 // An internal function but exported because it is cross-package; part of the implementation
 // of gotest.
-func RunBenchmarks(benchmarks []Benchmark) {
+func RunBenchmarks(matchString func(pat, str string) (bool, os.Error), benchmarks []Benchmark) {
 	// If no flag was specified, don't run benchmarks.
 	if len(*matchBenchmarks) == 0 {
 		return
 	}
-	re, err := CompileRegexp(*matchBenchmarks)
-	if err != "" {
-		println("invalid regexp for -benchmarks:", err)
-		os.Exit(1)
-	}
 	for _, Benchmark := range benchmarks {
-		if !re.MatchString(Benchmark.Name) {
+		matched, err := matchString(*matchBenchmarks, Benchmark.Name)
+		if err != nil {
+			println("invalid regexp for -benchmarks:", err)
+			os.Exit(1)
+		}
+		if !matched {
 			continue
 		}
 		b := &B{benchmark: Benchmark}
diff --git a/src/pkg/testing/regexp.go b/src/pkg/testing/regexp.go
deleted file mode 100644
index 9d2c8d5..0000000
--- a/src/pkg/testing/regexp.go
+++ /dev/null
@@ -1,751 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// The testing package implements a simple regular expression library.
-// It is a reduced version of the regular expression package suitable
-// for use in tests; it avoids many dependencies.
-//
-// The syntax of the regular expressions accepted is:
-//
-//	regexp:
-//		concatenation { '|' concatenation }
-//	concatenation:
-//		{ closure }
-//	closure:
-//		term [ '*' | '+' | '?' ]
-//	term:
-//		'^'
-//		'$'
-//		'.'
-//		character
-//		'[' [ '^' ] character-ranges ']'
-//		'(' regexp ')'
-//
-
-package testing
-
-import (
-	"utf8"
-)
-
-var debug = false
-
-// Error codes returned by failures to parse an expression.
-var (
-	ErrInternal            = "internal error"
-	ErrUnmatchedLpar       = "unmatched '('"
-	ErrUnmatchedRpar       = "unmatched ')'"
-	ErrUnmatchedLbkt       = "unmatched '['"
-	ErrUnmatchedRbkt       = "unmatched ']'"
-	ErrBadRange            = "bad range in character class"
-	ErrExtraneousBackslash = "extraneous backslash"
-	ErrBadClosure          = "repeated closure (**, ++, etc.)"
-	ErrBareClosure         = "closure applies to nothing"
-	ErrBadBackslash        = "illegal backslash escape"
-)
-
-// An instruction executed by the NFA
-type instr interface {
-	kind() int   // the type of this instruction: _CHAR, _ANY, etc.
-	next() instr // the instruction to execute after this one
-	setNext(i instr)
-	index() int
-	setIndex(i int)
-	print()
-}
-
-// Fields and methods common to all instructions
-type common struct {
-	_next  instr
-	_index int
-}
-
-func (c *common) next() instr     { return c._next }
-func (c *common) setNext(i instr) { c._next = i }
-func (c *common) index() int      { return c._index }
-func (c *common) setIndex(i int)  { c._index = i }
-
-// The representation of a compiled regular expression.
-// The public interface is entirely through methods.
-type Regexp struct {
-	expr  string // the original expression
-	inst  []instr
-	start instr
-	nbra  int // number of brackets in expression, for subexpressions
-}
-
-const (
-	_START     = iota // beginning of program
-	_END              // end of program: success
-	_BOT              // '^' beginning of text
-	_EOT              // '$' end of text
-	_CHAR             // 'a' regular character
-	_CHARCLASS        // [a-z] character class
-	_ANY              // '.' any character including newline
-	_NOTNL            // [^\n] special case: any character but newline
-	_BRA              // '(' parenthesized expression
-	_EBRA             // ')'; end of '(' parenthesized expression
-	_ALT              // '|' alternation
-	_NOP              // do nothing; makes it easy to link without patching
-)
-
-// --- START start of program
-type _Start struct {
-	common
-}
-
-func (start *_Start) kind() int { return _START }
-func (start *_Start) print()    { print("start") }
-
-// --- END end of program
-type _End struct {
-	common
-}
-
-func (end *_End) kind() int { return _END }
-func (end *_End) print()    { print("end") }
-
-// --- BOT beginning of text
-type _Bot struct {
-	common
-}
-
-func (bot *_Bot) kind() int { return _BOT }
-func (bot *_Bot) print()    { print("bot") }
-
-// --- EOT end of text
-type _Eot struct {
-	common
-}
-
-func (eot *_Eot) kind() int { return _EOT }
-func (eot *_Eot) print()    { print("eot") }
-
-// --- CHAR a regular character
-type _Char struct {
-	common
-	char int
-}
-
-func (char *_Char) kind() int { return _CHAR }
-func (char *_Char) print()    { print("char ", string(char.char)) }
-
-func newChar(char int) *_Char {
-	c := new(_Char)
-	c.char = char
-	return c
-}
-
-// --- CHARCLASS [a-z]
-
-type _CharClass struct {
-	common
-	char   int
-	negate bool // is character class negated? ([^a-z])
-	// stored pairwise: [a-z] is (a,z); x is (x,x):
-	ranges []int
-}
-
-func (cclass *_CharClass) kind() int { return _CHARCLASS }
-
-func (cclass *_CharClass) print() {
-	print("charclass")
-	if cclass.negate {
-		print(" (negated)")
-	}
-	for i := 0; i < len(cclass.ranges); i += 2 {
-		l := cclass.ranges[i]
-		r := cclass.ranges[i+1]
-		if l == r {
-			print(" [", string(l), "]")
-		} else {
-			print(" [", string(l), "-", string(r), "]")
-		}
-	}
-}
-
-func (cclass *_CharClass) addRange(a, b int) {
-	// range is a through b inclusive
-	cclass.ranges = append(cclass.ranges, a, b)
-}
-
-func (cclass *_CharClass) matches(c int) bool {
-	for i := 0; i < len(cclass.ranges); i = i + 2 {
-		min := cclass.ranges[i]
-		max := cclass.ranges[i+1]
-		if min <= c && c <= max {
-			return !cclass.negate
-		}
-	}
-	return cclass.negate
-}
-
-func newCharClass() *_CharClass {
-	c := new(_CharClass)
-	c.ranges = make([]int, 0, 20)
-	return c
-}
-
-// --- ANY any character
-type _Any struct {
-	common
-}
-
-func (any *_Any) kind() int { return _ANY }
-func (any *_Any) print()    { print("any") }
-
-// --- NOTNL any character but newline
-type _NotNl struct {
-	common
-}
-
-func (notnl *_NotNl) kind() int { return _NOTNL }
-func (notnl *_NotNl) print()    { print("notnl") }
-
-// --- BRA parenthesized expression
-type _Bra struct {
-	common
-	n int // subexpression number
-}
-
-func (bra *_Bra) kind() int { return _BRA }
-func (bra *_Bra) print()    { print("bra", bra.n) }
-
-// --- EBRA end of parenthesized expression
-type _Ebra struct {
-	common
-	n int // subexpression number
-}
-
-func (ebra *_Ebra) kind() int { return _EBRA }
-func (ebra *_Ebra) print()    { print("ebra ", ebra.n) }
-
-// --- ALT alternation
-type _Alt struct {
-	common
-	left instr // other branch
-}
-
-func (alt *_Alt) kind() int { return _ALT }
-func (alt *_Alt) print()    { print("alt(", alt.left.index(), ")") }
-
-// --- NOP no operation
-type _Nop struct {
-	common
-}
-
-func (nop *_Nop) kind() int { return _NOP }
-func (nop *_Nop) print()    { print("nop") }
-
-func (re *Regexp) add(i instr) instr {
-	i.setIndex(len(re.inst))
-	re.inst = append(re.inst, i)
-	return i
-}
-
-type parser struct {
-	re    *Regexp
-	nlpar int // number of unclosed lpars
-	pos   int
-	ch    int
-}
-
-func (p *parser) error(err string) {
-	panic(err)
-}
-
-const endOfFile = -1
-
-func (p *parser) c() int { return p.ch }
-
-func (p *parser) nextc() int {
-	if p.pos >= len(p.re.expr) {
-		p.ch = endOfFile
-	} else {
-		c, w := utf8.DecodeRuneInString(p.re.expr[p.pos:])
-		p.ch = c
-		p.pos += w
-	}
-	return p.ch
-}
-
-func newParser(re *Regexp) *parser {
-	p := new(parser)
-	p.re = re
-	p.nextc() // load p.ch
-	return p
-}
-
-func special(c int) bool {
-	s := `\.+*?()|[]^$`
-	for i := 0; i < len(s); i++ {
-		if c == int(s[i]) {
-			return true
-		}
-	}
-	return false
-}
-
-func specialcclass(c int) bool {
-	s := `\-[]`
-	for i := 0; i < len(s); i++ {
-		if c == int(s[i]) {
-			return true
-		}
-	}
-	return false
-}
-
-func (p *parser) charClass() instr {
-	cc := newCharClass()
-	if p.c() == '^' {
-		cc.negate = true
-		p.nextc()
-	}
-	left := -1
-	for {
-		switch c := p.c(); c {
-		case ']', endOfFile:
-			if left >= 0 {
-				p.error(ErrBadRange)
-			}
-			// Is it [^\n]?
-			if cc.negate && len(cc.ranges) == 2 &&
-				cc.ranges[0] == '\n' && cc.ranges[1] == '\n' {
-				nl := new(_NotNl)
-				p.re.add(nl)
-				return nl
-			}
-			p.re.add(cc)
-			return cc
-		case '-': // do this before backslash processing
-			p.error(ErrBadRange)
-		case '\\':
-			c = p.nextc()
-			switch {
-			case c == endOfFile:
-				p.error(ErrExtraneousBackslash)
-			case c == 'n':
-				c = '\n'
-			case specialcclass(c):
-			// c is as delivered
-			default:
-				p.error(ErrBadBackslash)
-			}
-			fallthrough
-		default:
-			p.nextc()
-			switch {
-			case left < 0: // first of pair
-				if p.c() == '-' { // range
-					p.nextc()
-					left = c
-				} else { // single char
-					cc.addRange(c, c)
-				}
-			case left <= c: // second of pair
-				cc.addRange(left, c)
-				left = -1
-			default:
-				p.error(ErrBadRange)
-			}
-		}
-	}
-	return nil
-}
-
-func (p *parser) term() (start, end instr) {
-	switch c := p.c(); c {
-	case '|', endOfFile:
-		return nil, nil
-	case '*', '+':
-		p.error(ErrBareClosure)
-		return
-	case ')':
-		if p.nlpar == 0 {
-			p.error(ErrUnmatchedRpar)
-		}
-		return nil, nil
-	case ']':
-		p.error(ErrUnmatchedRbkt)
-	case '^':
-		p.nextc()
-		start = p.re.add(new(_Bot))
-		return start, start
-	case '$':
-		p.nextc()
-		start = p.re.add(new(_Eot))
-		return start, start
-	case '.':
-		p.nextc()
-		start = p.re.add(new(_Any))
-		return start, start
-	case '[':
-		p.nextc()
-		start = p.charClass()
-		if p.c() != ']' {
-			p.error(ErrUnmatchedLbkt)
-		}
-		p.nextc()
-		return start, start
-	case '(':
-		p.nextc()
-		p.nlpar++
-		p.re.nbra++ // increment first so first subexpr is \1
-		nbra := p.re.nbra
-		start, end = p.regexp()
-		if p.c() != ')' {
-			p.error(ErrUnmatchedLpar)
-		}
-		p.nlpar--
-		p.nextc()
-		bra := new(_Bra)
-		p.re.add(bra)
-		ebra := new(_Ebra)
-		p.re.add(ebra)
-		bra.n = nbra
-		ebra.n = nbra
-		if start == nil {
-			if end == nil {
-				p.error(ErrInternal)
-			}
-			start = ebra
-		} else {
-			end.setNext(ebra)
-		}
-		bra.setNext(start)
-		return bra, ebra
-	case '\\':
-		c = p.nextc()
-		switch {
-		case c == endOfFile:
-			p.error(ErrExtraneousBackslash)
-			return
-		case c == 'n':
-			c = '\n'
-		case special(c):
-		// c is as delivered
-		default:
-			p.error(ErrBadBackslash)
-		}
-		fallthrough
-	default:
-		p.nextc()
-		start = newChar(c)
-		p.re.add(start)
-		return start, start
-	}
-	panic("unreachable")
-}
-
-func (p *parser) closure() (start, end instr) {
-	start, end = p.term()
-	if start == nil {
-		return
-	}
-	switch p.c() {
-	case '*':
-		// (start,end)*:
-		alt := new(_Alt)
-		p.re.add(alt)
-		end.setNext(alt) // after end, do alt
-		alt.left = start // alternate brach: return to start
-		start = alt      // alt becomes new (start, end)
-		end = alt
-	case '+':
-		// (start,end)+:
-		alt := new(_Alt)
-		p.re.add(alt)
-		end.setNext(alt) // after end, do alt
-		alt.left = start // alternate brach: return to start
-		end = alt        // start is unchanged; end is alt
-	case '?':
-		// (start,end)?:
-		alt := new(_Alt)
-		p.re.add(alt)
-		nop := new(_Nop)
-		p.re.add(nop)
-		alt.left = start // alternate branch is start
-		alt.setNext(nop) // follow on to nop
-		end.setNext(nop) // after end, go to nop
-		start = alt      // start is now alt
-		end = nop        // end is nop pointed to by both branches
-	default:
-		return
-	}
-	switch p.nextc() {
-	case '*', '+', '?':
-		p.error(ErrBadClosure)
-	}
-	return
-}
-
-func (p *parser) concatenation() (start, end instr) {
-	for {
-		nstart, nend := p.closure()
-		switch {
-		case nstart == nil: // end of this concatenation
-			if start == nil { // this is the empty string
-				nop := p.re.add(new(_Nop))
-				return nop, nop
-			}
-			return
-		case start == nil: // this is first element of concatenation
-			start, end = nstart, nend
-		default:
-			end.setNext(nstart)
-			end = nend
-		}
-	}
-	panic("unreachable")
-}
-
-func (p *parser) regexp() (start, end instr) {
-	start, end = p.concatenation()
-	for {
-		switch p.c() {
-		default:
-			return
-		case '|':
-			p.nextc()
-			nstart, nend := p.concatenation()
-			alt := new(_Alt)
-			p.re.add(alt)
-			alt.left = start
-			alt.setNext(nstart)
-			nop := new(_Nop)
-			p.re.add(nop)
-			end.setNext(nop)
-			nend.setNext(nop)
-			start, end = alt, nop
-		}
-	}
-	panic("unreachable")
-}
-
-func unNop(i instr) instr {
-	for i.kind() == _NOP {
-		i = i.next()
-	}
-	return i
-}
-
-func (re *Regexp) eliminateNops() {
-	for i := 0; i < len(re.inst); i++ {
-		inst := re.inst[i]
-		if inst.kind() == _END {
-			continue
-		}
-		inst.setNext(unNop(inst.next()))
-		if inst.kind() == _ALT {
-			alt := inst.(*_Alt)
-			alt.left = unNop(alt.left)
-		}
-	}
-}
-
-func (re *Regexp) doParse() {
-	p := newParser(re)
-	start := new(_Start)
-	re.add(start)
-	s, e := p.regexp()
-	start.setNext(s)
-	re.start = start
-	e.setNext(re.add(new(_End)))
-	re.eliminateNops()
-}
-
-// CompileRegexp parses a regular expression and returns, if successful, a Regexp
-// object that can be used to match against text.
-func CompileRegexp(str string) (regexp *Regexp, error string) {
-	regexp = new(Regexp)
-	// doParse will panic if there is a parse error.
-	defer func() {
-		if e := recover(); e != nil {
-			regexp = nil
-			error = e.(string) // Will re-panic if error was not a string, e.g. nil-pointer exception
-		}
-	}()
-	regexp.expr = str
-	regexp.inst = make([]instr, 0, 20)
-	regexp.doParse()
-	return
-}
-
-// MustCompileRegexp is like CompileRegexp but panics if the expression cannot be parsed.
-// It simplifies safe initialization of global variables holding compiled regular
-// expressions.
-func MustCompile(str string) *Regexp {
-	regexp, error := CompileRegexp(str)
-	if error != "" {
-		panic(`regexp: compiling "` + str + `": ` + error)
-	}
-	return regexp
-}
-
-type state struct {
-	inst  instr // next instruction to execute
-	match []int // pairs of bracketing submatches. 0th is start,end
-}
-
-// Append new state to to-do list.  Leftmost-longest wins so avoid
-// adding a state that's already active.
-func addState(s []state, inst instr, match []int) []state {
-	index := inst.index()
-	l := len(s)
-	pos := match[0]
-	// TODO: Once the state is a vector and we can do insert, have inputs always
-	// go in order correctly and this "earlier" test is never necessary,
-	for i := 0; i < l; i++ {
-		if s[i].inst.index() == index && // same instruction
-			s[i].match[0] < pos { // earlier match already going; lefmost wins
-			return s
-		}
-	}
-	if l == cap(s) {
-		s1 := make([]state, 2*l)[0:l]
-		for i := 0; i < l; i++ {
-			s1[i] = s[i]
-		}
-		s = s1
-	}
-	s = s[0 : l+1]
-	s[l].inst = inst
-	s[l].match = match
-	return s
-}
-
-// Accepts either string or bytes - the logic is identical either way.
-// If bytes == nil, scan str.
-func (re *Regexp) doExecute(str string, bytes []byte, pos int) []int {
-	var s [2][]state // TODO: use a vector when state values (not ptrs) can be vector elements
-	s[0] = make([]state, 10)[0:0]
-	s[1] = make([]state, 10)[0:0]
-	in, out := 0, 1
-	var final state
-	found := false
-	end := len(str)
-	if bytes != nil {
-		end = len(bytes)
-	}
-	for pos <= end {
-		if !found {
-			// prime the pump if we haven't seen a match yet
-			match := make([]int, 2*(re.nbra+1))
-			for i := 0; i < len(match); i++ {
-				match[i] = -1 // no match seen; catches cases like "a(b)?c" on "ac"
-			}
-			match[0] = pos
-			s[out] = addState(s[out], re.start.next(), match)
-		}
-		in, out = out, in    // old out state is new in state
-		s[out] = s[out][0:0] // clear out state
-		if len(s[in]) == 0 {
-			// machine has completed
-			break
-		}
-		charwidth := 1
-		c := endOfFile
-		if pos < end {
-			if bytes == nil {
-				c, charwidth = utf8.DecodeRuneInString(str[pos:end])
-			} else {
-				c, charwidth = utf8.DecodeRune(bytes[pos:end])
-			}
-		}
-		for i := 0; i < len(s[in]); i++ {
-			st := s[in][i]
-			switch s[in][i].inst.kind() {
-			case _BOT:
-				if pos == 0 {
-					s[in] = addState(s[in], st.inst.next(), st.match)
-				}
-			case _EOT:
-				if pos == end {
-					s[in] = addState(s[in], st.inst.next(), st.match)
-				}
-			case _CHAR:
-				if c == st.inst.(*_Char).char {
-					s[out] = addState(s[out], st.inst.next(), st.match)
-				}
-			case _CHARCLASS:
-				if st.inst.(*_CharClass).matches(c) {
-					s[out] = addState(s[out], st.inst.next(), st.match)
-				}
-			case _ANY:
-				if c != endOfFile {
-					s[out] = addState(s[out], st.inst.next(), st.match)
-				}
-			case _NOTNL:
-				if c != endOfFile && c != '\n' {
-					s[out] = addState(s[out], st.inst.next(), st.match)
-				}
-			case _BRA:
-				n := st.inst.(*_Bra).n
-				st.match[2*n] = pos
-				s[in] = addState(s[in], st.inst.next(), st.match)
-			case _EBRA:
-				n := st.inst.(*_Ebra).n
-				st.match[2*n+1] = pos
-				s[in] = addState(s[in], st.inst.next(), st.match)
-			case _ALT:
-				s[in] = addState(s[in], st.inst.(*_Alt).left, st.match)
-				// give other branch a copy of this match vector
-				s1 := make([]int, 2*(re.nbra+1))
-				for i := 0; i < len(s1); i++ {
-					s1[i] = st.match[i]
-				}
-				s[in] = addState(s[in], st.inst.next(), s1)
-			case _END:
-				// choose leftmost longest
-				if !found || // first
-					st.match[0] < final.match[0] || // leftmost
-					(st.match[0] == final.match[0] && pos > final.match[1]) { // longest
-					final = st
-					final.match[1] = pos
-				}
-				found = true
-			default:
-				st.inst.print()
-				panic("unknown instruction in execute")
-			}
-		}
-		pos += charwidth
-	}
-	return final.match
-}
-
-
-// MatchString returns whether the Regexp matches the string s.
-// The return value is a boolean: true for match, false for no match.
-func (re *Regexp) MatchString(s string) bool { return len(re.doExecute(s, nil, 0)) > 0 }
-
-
-// Match returns whether the Regexp matches the byte slice b.
-// The return value is a boolean: true for match, false for no match.
-func (re *Regexp) Match(b []byte) bool { return len(re.doExecute("", b, 0)) > 0 }
-
-
-// MatchString checks whether a textual regular expression
-// matches a string.  More complicated queries need
-// to use Compile and the full Regexp interface.
-func MatchString(pattern string, s string) (matched bool, error string) {
-	re, err := CompileRegexp(pattern)
-	if err != "" {
-		return false, err
-	}
-	return re.MatchString(s), ""
-}
-
-
-// Match checks whether a textual regular expression
-// matches a byte slice.  More complicated queries need
-// to use Compile and the full Regexp interface.
-func Match(pattern string, b []byte) (matched bool, error string) {
-	re, err := CompileRegexp(pattern)
-	if err != "" {
-		return false, err
-	}
-	return re.Match(b), ""
-}
diff --git a/src/pkg/testing/regexp_test.go b/src/pkg/testing/regexp_test.go
deleted file mode 100644
index 1e11399..0000000
--- a/src/pkg/testing/regexp_test.go
+++ /dev/null
@@ -1,143 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package testing
-
-var good_re = []string{
-	``,
-	`.`,
-	`^.$`,
-	`a`,
-	`a*`,
-	`a+`,
-	`a?`,
-	`a|b`,
-	`a*|b*`,
-	`(a*|b)(c*|d)`,
-	`[a-z]`,
-	`[a-abc-c\-\]\[]`,
-	`[a-z]+`,
-	`[]`,
-	`[abc]`,
-	`[^1234]`,
-	`[^\n]`,
-}
-
-// TODO: nice to do this with a map
-type stringError struct {
-	re  string
-	err string
-}
-
-var bad_re = []stringError{
-	{`*`, ErrBareClosure},
-	{`(abc`, ErrUnmatchedLpar},
-	{`abc)`, ErrUnmatchedRpar},
-	{`x[a-z`, ErrUnmatchedLbkt},
-	{`abc]`, ErrUnmatchedRbkt},
-	{`[z-a]`, ErrBadRange},
-	{`abc\`, ErrExtraneousBackslash},
-	{`a**`, ErrBadClosure},
-	{`a*+`, ErrBadClosure},
-	{`a??`, ErrBadClosure},
-	{`*`, ErrBareClosure},
-	{`\x`, ErrBadBackslash},
-}
-
-type vec []int
-
-type tester struct {
-	re    string
-	text  string
-	match vec
-}
-
-var matches = []tester{
-	{``, "", vec{0, 0}},
-	{`a`, "a", vec{0, 1}},
-	{`x`, "y", vec{}},
-	{`b`, "abc", vec{1, 2}},
-	{`.`, "a", vec{0, 1}},
-	{`.*`, "abcdef", vec{0, 6}},
-	{`^abcd$`, "abcd", vec{0, 4}},
-	{`^bcd'`, "abcdef", vec{}},
-	{`^abcd$`, "abcde", vec{}},
-	{`a+`, "baaab", vec{1, 4}},
-	{`a*`, "baaab", vec{0, 0}},
-	{`[a-z]+`, "abcd", vec{0, 4}},
-	{`[^a-z]+`, "ab1234cd", vec{2, 6}},
-	{`[a\-\]z]+`, "az]-bcz", vec{0, 4}},
-	{`[^\n]+`, "abcd\n", vec{0, 4}},
-	{`[日本語]+`, "日本語日本語", vec{0, 18}},
-	{`()`, "", vec{0, 0, 0, 0}},
-	{`(a)`, "a", vec{0, 1, 0, 1}},
-	{`(.)(.)`, "日a", vec{0, 4, 0, 3, 3, 4}},
-	{`(.*)`, "", vec{0, 0, 0, 0}},
-	{`(.*)`, "abcd", vec{0, 4, 0, 4}},
-	{`(..)(..)`, "abcd", vec{0, 4, 0, 2, 2, 4}},
-	{`(([^xyz]*)(d))`, "abcd", vec{0, 4, 0, 4, 0, 3, 3, 4}},
-	{`((a|b|c)*(d))`, "abcd", vec{0, 4, 0, 4, 2, 3, 3, 4}},
-	{`(((a|b|c)*)(d))`, "abcd", vec{0, 4, 0, 4, 0, 3, 2, 3, 3, 4}},
-	{`a*(|(b))c*`, "aacc", vec{0, 4, 2, 2, -1, -1}},
-}
-
-func compileTest(t *T, expr string, error string) *Regexp {
-	re, err := CompileRegexp(expr)
-	if err != error {
-		t.Error("compiling `", expr, "`; unexpected error: ", err)
-	}
-	return re
-}
-
-func TestGoodCompile(t *T) {
-	for i := 0; i < len(good_re); i++ {
-		compileTest(t, good_re[i], "")
-	}
-}
-
-func TestBadCompile(t *T) {
-	for i := 0; i < len(bad_re); i++ {
-		compileTest(t, bad_re[i].re, bad_re[i].err)
-	}
-}
-
-func matchTest(t *T, expr string, str string, match []int) {
-	re := compileTest(t, expr, "")
-	if re == nil {
-		return
-	}
-	m := re.MatchString(str)
-	if m != (len(match) > 0) {
-		t.Error("MatchString failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0)
-	}
-	// now try bytes
-	m = re.Match([]byte(str))
-	if m != (len(match) > 0) {
-		t.Error("Match failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0)
-	}
-}
-
-func TestMatch(t *T) {
-	for i := 0; i < len(matches); i++ {
-		test := &matches[i]
-		matchTest(t, test.re, test.text, test.match)
-	}
-}
-
-func matchFunctionTest(t *T, expr string, str string, match []int) {
-	m, err := MatchString(expr, str)
-	if err == "" {
-		return
-	}
-	if m != (len(match) > 0) {
-		t.Error("function Match failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0)
-	}
-}
-
-func TestMatchFunction(t *T) {
-	for i := 0; i < len(matches); i++ {
-		test := &matches[i]
-		matchFunctionTest(t, test.re, test.text, test.match)
-	}
-}
diff --git a/src/pkg/testing/testing.go b/src/pkg/testing/testing.go
index a3a7e59..b01f633 100644
--- a/src/pkg/testing/testing.go
+++ b/src/pkg/testing/testing.go
@@ -135,19 +135,19 @@
 
 // An internal function but exported because it is cross-package; part of the implementation
 // of gotest.
-func Main(tests []Test) {
+func Main(matchString func(pat, str string) (bool, os.Error), tests []Test) {
 	flag.Parse()
 	ok := true
 	if len(tests) == 0 {
 		println("testing: warning: no tests to run")
 	}
-	re, err := CompileRegexp(*match)
-	if err != "" {
-		println("invalid regexp for -match:", err)
-		os.Exit(1)
-	}
 	for i := 0; i < len(tests); i++ {
-		if !re.MatchString(tests[i].Name) {
+		matched, err := matchString(*match, tests[i].Name)
+		if err != nil {
+			println("invalid regexp for -match:", err)
+			os.Exit(1)
+		}
+		if !matched {
 			continue
 		}
 		if *chatty {