Initial commit: Go 1.23 release state

test/closure.go

@@ -0,0 +1,128 @@
+// run
+
+// 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.
+
+// Test the behavior of closures.
+
+package main
+
+import "runtime"
+
+var c = make(chan int)
+
+func check(a []int) {
+	for i := 0; i < len(a); i++ {
+		n := <-c
+		if n != a[i] {
+			println("want", a[i], "got", n, "at", i)
+			panic("fail")
+		}
+	}
+}
+
+func f() {
+	var i, j int
+
+	i = 1
+	j = 2
+	f := func() {
+		c <- i
+		i = 4
+		g := func() {
+			c <- i
+			c <- j
+		}
+		g()
+		c <- i
+	}
+	j = 5
+	f()
+}
+
+// Accumulator generator
+func accum(n int) func(int) int {
+	return func(i int) int {
+		n += i
+		return n
+	}
+}
+
+func g(a, b func(int) int) {
+	c <- a(2)
+	c <- b(3)
+	c <- a(4)
+	c <- b(5)
+}
+
+func h() {
+	var x8 byte = 100
+	var x64 int64 = 200
+
+	c <- int(x8)
+	c <- int(x64)
+	f := func(z int) {
+		g := func() {
+			c <- int(x8)
+			c <- int(x64)
+			c <- z
+		}
+		g()
+		c <- int(x8)
+		c <- int(x64)
+		c <- int(z)
+	}
+	x8 = 101
+	x64 = 201
+	f(500)
+}
+
+func newfunc() func(int) int { return func(x int) int { return x } }
+
+func main() {
+	runtime.GOMAXPROCS(1)
+	var fail bool
+
+	go f()
+	check([]int{1, 4, 5, 4})
+
+	a := accum(0)
+	b := accum(1)
+	go g(a, b)
+	check([]int{2, 4, 6, 9})
+
+	go h()
+	check([]int{100, 200, 101, 201, 500, 101, 201, 500})
+
+	memstats := new(runtime.MemStats)
+	runtime.ReadMemStats(memstats)
+	n0 := memstats.Mallocs
+
+	x, y := newfunc(), newfunc()
+	if x(1) != 1 || y(2) != 2 {
+		println("newfunc returned broken funcs")
+		fail = true
+	}
+
+	runtime.ReadMemStats(memstats)
+	if n0 != memstats.Mallocs {
+		println("newfunc allocated unexpectedly")
+		fail = true
+	}
+
+	ff(1)
+
+	if fail {
+		panic("fail")
+	}
+}
+
+func ff(x int) {
+	call(func() {
+		_ = x
+	})
+}
+
+func call(func()) {
+}