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Diffstat (limited to 'doc/progs/go1.go')
-rw-r--r-- | doc/progs/go1.go | 245 |
1 files changed, 0 insertions, 245 deletions
diff --git a/doc/progs/go1.go b/doc/progs/go1.go deleted file mode 100644 index 50fd93441f..0000000000 --- a/doc/progs/go1.go +++ /dev/null @@ -1,245 +0,0 @@ -// 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 examples to embed in the Go 1 release notes document. - -package main - -import ( - "errors" - "flag" - "fmt" - "log" - "os" - "path/filepath" - "testing" - "time" - "unicode" -) - -func main() { - flag.Parse() - stringAppend() - mapDelete() - mapIteration() - multipleAssignment() - structEquality() - compositeLiterals() - runeType() - errorExample() - timePackage() - walkExample() - osIsExist() -} - -var timeout = flag.Duration("timeout", 30*time.Second, "how long to wait for completion") - -func init() { - // canonicalize the logging - log.SetFlags(0) -} - -func mapDelete() { - m := map[string]int{"7": 7, "23": 23} - k := "7" - delete(m, k) - if m["7"] != 0 || m["23"] != 23 { - log.Fatal("mapDelete:", m) - } -} - -func stringAppend() { - greeting := []byte{} - greeting = append(greeting, []byte("hello ")...) - greeting = append(greeting, "world"...) - if string(greeting) != "hello world" { - log.Fatal("stringAppend: ", string(greeting)) - } -} - -func mapIteration() { - m := map[string]int{"Sunday": 0, "Monday": 1} - for name, value := range m { - // This loop should not assume Sunday will be visited first. - f(name, value) - } -} - -func f(string, int) { -} - -func assert(t bool) { - if !t { - log.Panic("assertion fail") - } -} - -func multipleAssignment() { - sa := []int{1, 2, 3} - i := 0 - i, sa[i] = 1, 2 // sets i = 1, sa[0] = 2 - - sb := []int{1, 2, 3} - j := 0 - sb[j], j = 2, 1 // sets sb[0] = 2, j = 1 - - sc := []int{1, 2, 3} - sc[0], sc[0] = 1, 2 // sets sc[0] = 1, then sc[0] = 2 (so sc[0] = 2 at end) - - assert(i == 1 && sa[0] == 2) - assert(j == 1 && sb[0] == 2) - assert(sc[0] == 2) -} - -func structEquality() { - type Day struct { - long string - short string - } - Christmas := Day{"Christmas", "XMas"} - Thanksgiving := Day{"Thanksgiving", "Turkey"} - holiday := map[Day]bool{ - Christmas: true, - Thanksgiving: true, - } - fmt.Printf("Christmas is a holiday: %t\n", holiday[Christmas]) -} - -func compositeLiterals() { - type Date struct { - month string - day int - } - // Struct values, fully qualified; always legal. - holiday1 := []Date{ - Date{"Feb", 14}, - Date{"Nov", 11}, - Date{"Dec", 25}, - } - // Struct values, type name elided; always legal. - holiday2 := []Date{ - {"Feb", 14}, - {"Nov", 11}, - {"Dec", 25}, - } - // Pointers, fully qualified, always legal. - holiday3 := []*Date{ - &Date{"Feb", 14}, - &Date{"Nov", 11}, - &Date{"Dec", 25}, - } - // Pointers, type name elided; legal in Go 1. - holiday4 := []*Date{ - {"Feb", 14}, - {"Nov", 11}, - {"Dec", 25}, - } - // STOP OMIT - _, _, _, _ = holiday1, holiday2, holiday3, holiday4 -} - -func runeType() { - // STARTRUNE OMIT - delta := 'δ' // delta has type rune. - var DELTA rune - DELTA = unicode.ToUpper(delta) - epsilon := unicode.ToLower(DELTA + 1) - if epsilon != 'δ'+1 { - log.Fatal("inconsistent casing for Greek") - } - // ENDRUNE OMIT -} - -// START ERROR EXAMPLE OMIT -type SyntaxError struct { - File string - Line int - Message string -} - -func (se *SyntaxError) Error() string { - return fmt.Sprintf("%s:%d: %s", se.File, se.Line, se.Message) -} - -// END ERROR EXAMPLE OMIT - -func errorExample() { - var ErrSyntax = errors.New("syntax error") - _ = ErrSyntax - se := &SyntaxError{"file", 7, "error"} - got := fmt.Sprint(se) - const expect = "file:7: error" - if got != expect { - log.Fatalf("errorsPackage: expected %q got %q", expect, got) - } -} - -// sleepUntil sleeps until the specified time. It returns immediately if it's too late. -func sleepUntil(wakeup time.Time) { - now := time.Now() // A Time. - if !wakeup.After(now) { - return - } - delta := wakeup.Sub(now) // A Duration. - fmt.Printf("Sleeping for %.3fs\n", delta.Seconds()) - time.Sleep(delta) -} - -func timePackage() { - sleepUntil(time.Now().Add(123 * time.Millisecond)) -} - -func walkExample() { - // STARTWALK OMIT - markFn := func(path string, info os.FileInfo, err error) error { - if path == "pictures" { // Will skip walking of directory pictures and its contents. - return filepath.SkipDir - } - if err != nil { - return err - } - log.Println(path) - return nil - } - err := filepath.Walk(".", markFn) - if err != nil { - log.Fatal(err) - } - // ENDWALK OMIT -} - -func initializationFunction(c chan int) { - c <- 1 -} - -var PackageGlobal int - -func init() { - c := make(chan int) - go initializationFunction(c) - PackageGlobal = <-c -} - -func BenchmarkSprintf(b *testing.B) { - // Verify correctness before running benchmark. - b.StopTimer() - got := fmt.Sprintf("%x", 23) - const expect = "17" - if expect != got { - b.Fatalf("expected %q; got %q", expect, got) - } - b.StartTimer() - for i := 0; i < b.N; i++ { - fmt.Sprintf("%x", 23) - } -} - -func osIsExist() { - name := "go1.go" - f, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600) - if os.IsExist(err) { - log.Printf("%s already exists", name) - } - _ = f -} |