doc: add Defer, Panic, and Recover article
Originally published on The Go Programming Language Blog, August 4 2010.
http://blog.golang.org/2010/08/defer-panic-and-recover.html
Update #2547
R=golang-dev, r, r
CC=golang-dev
https://golang.org/cl/5479053
diff --git a/doc/progs/defer.go b/doc/progs/defer.go
new file mode 100644
index 0000000..f52278a
--- /dev/null
+++ b/doc/progs/defer.go
@@ -0,0 +1,53 @@
+// Copyright 2011 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.
+
+// This file contains the code snippets included in "Defer, Panic, an Recover."
+
+package main
+
+import (
+ "fmt"
+ "io"
+ "os"
+)
+
+func a() {
+ i := 0
+ defer fmt.Println(i)
+ i++
+ return
+}
+// STOP OMIT
+
+func b() {
+ for i := 0; i < 4; i++ {
+ defer fmt.Print(i)
+ }
+}
+// STOP OMIT
+
+func c() (i int) {
+ defer func() { i++ }()
+ return 1
+}
+// STOP OMIT
+
+// Intial version.
+func CopyFile(dstName, srcName string) (written int64, err error) {
+ src, err := os.Open(srcName)
+ if err != nil {
+ return
+ }
+
+ dst, err := os.Create(dstName)
+ if err != nil {
+ return
+ }
+
+ written, err = io.Copy(dst, src)
+ dst.Close()
+ src.Close()
+ return
+}
+// STOP OMIT
diff --git a/doc/progs/defer2.go b/doc/progs/defer2.go
new file mode 100644
index 0000000..be6791d
--- /dev/null
+++ b/doc/progs/defer2.go
@@ -0,0 +1,56 @@
+// Copyright 2011 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.
+
+// This file contains the code snippets included in "Defer, Panic, an Recover."
+
+package main
+
+import "fmt"
+import "io" // OMIT
+import "os" // OMIT
+
+func main() {
+ f()
+ fmt.Println("Returned normally from f.")
+}
+
+func f() {
+ defer func() {
+ if r := recover(); r != nil {
+ fmt.Println("Recovered in f", r)
+ }
+ }()
+ fmt.Println("Calling g.")
+ g(0)
+ fmt.Println("Returned normally from g.")
+}
+
+func g(i int) {
+ if i > 3 {
+ fmt.Println("Panicking!")
+ panic(fmt.Sprintf("%v", i))
+ }
+ defer fmt.Println("Defer in g", i)
+ fmt.Println("Printing in g", i)
+ g(i + 1)
+}
+// STOP OMIT
+
+// Revised version.
+func CopyFile(dstName, srcName string) (written int64, err error) {
+ src, err := os.Open(srcName)
+ if err != nil {
+ return
+ }
+ defer src.Close()
+
+ dst, err := os.Create(dstName)
+ if err != nil {
+ return
+ }
+ defer dst.Close()
+
+ return io.Copy(dst, src)
+}
+// STOP OMIT
diff --git a/doc/progs/run b/doc/progs/run
index e90e307..dd58639 100755
--- a/doc/progs/run
+++ b/doc/progs/run
@@ -20,25 +20,41 @@
$GC file.go
fi
+defer_panic_recover="
+ defer.go
+ defer2.go
+"
+
+effective_go="
+ eff_bytesize.go
+ eff_qr.go
+ eff_sequence.go
+"
+
+go_tutorial="
+ cat.go
+ cat_rot13.go
+ echo.go
+ file.go
+ helloworld.go
+ helloworld3.go
+ print.go
+ print_string.go
+ server.go
+ server1.go
+ sieve.go
+ sieve1.go
+ sort.go
+ sortmain.go
+ strings.go
+ sum.go
+"
+
for i in \
- helloworld.go \
- helloworld3.go \
- echo.go \
- cat.go \
- cat_rot13.go \
- sum.go \
- sort.go \
- sortmain.go \
- print.go \
- print_string.go \
- sieve.go \
- sieve1.go \
- server1.go \
- strings.go \
- eff_bytesize.go\
- eff_qr.go \
- eff_sequence.go\
- go1.go\
+ $defer_panic_recover \
+ $effective_go \
+ $go_tutorial \
+ go1.go \
; do
$GC $i
done
