gcc/testsuite/go.test/test/closure.go

   1 // $G $D/$F.go && $L $F.$A && ./$A.out
   2
   3 // Copyright 2009 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 package main
   8
   9 var c = make(chan int)
  10
  11 func check(a []int) {
  12         for i := 0; i < len(a); i++ {
  13                 n := <-c
  14                 if n != a[i] {
  15                         println("want", a[i], "got", n, "at", i)
  16                         panic("fail")
  17                 }
  18         }
  19 }
  20
  21 func f() {
  22         var i, j int
  23
  24         i = 1
  25         j = 2
  26         f := func() {
  27                 c <- i
  28                 i = 4
  29                 g := func() {
  30                         c <- i
  31                         c <- j
  32                 }
  33                 g()
  34                 c <- i
  35         }
  36         j = 5
  37         f()
  38 }
  39
  40 // Accumulator generator
  41 func accum(n int) func(int) int {
  42         return func(i int) int {
  43                 n += i
  44                 return n
  45         }
  46 }
  47
  48 func g(a, b func(int) int) {
  49         c <- a(2)
  50         c <- b(3)
  51         c <- a(4)
  52         c <- b(5)
  53 }
  54
  55 func h() {
  56         var x8 byte = 100
  57         var x64 int64 = 200
  58
  59         c <- int(x8)
  60         c <- int(x64)
  61         f := func(z int) {
  62                 g := func() {
  63                         c <- int(x8)
  64                         c <- int(x64)
  65                         c <- z
  66                 }
  67                 g()
  68                 c <- int(x8)
  69                 c <- int(x64)
  70                 c <- int(z)
  71         }
  72         x8 = 101
  73         x64 = 201
  74         f(500)
  75 }
  76
  77 func newfunc() func(int) int { return func(x int) int { return x } }
  78
  79
  80 func main() {
  81         go f()
  82         check([]int{1, 4, 5, 4})
  83
  84         a := accum(0)
  85         b := accum(1)
  86         go g(a, b)
  87         check([]int{2, 4, 6, 9})
  88
  89         go h()
  90         check([]int{100, 200, 101, 201, 500, 101, 201, 500})
  91
  92         x, y := newfunc(), newfunc()
  93         if x == y {
  94                 println("newfunc returned same func")
  95                 panic("fail")
  96         }
  97         if x(1) != 1 || y(2) != 2 {
  98                 println("newfunc returned broken funcs")
  99                 panic("fail")
 100         }
 101 }