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// 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 'for range' construct.
package main
// test range over channels
func gen(c chan int, lo, hi int) {
for i := lo; i <= hi; i++ {
c <- i
}
close(c)
}
func seq(lo, hi int) chan int {
c := make(chan int)
go gen(c, lo, hi)
return c
}
func testchan() {
s := ""
for i := range seq('a', 'z') {
s += string(i)
}
if s != "abcdefghijklmnopqrstuvwxyz" {
println("Wanted lowercase alphabet; got", s)
panic("fail")
}
}
// test that range over slice only evaluates
// the expression after "range" once.
var nmake = 0
func makeslice() []int {
nmake++
return []int{1, 2, 3, 4, 5}
}
func testslice() {
s := 0
nmake = 0
for _, v := range makeslice() {
s += v
}
if nmake != 1 {
println("range called makeslice", nmake, "times")
panic("fail")
}
if s != 15 {
println("wrong sum ranging over makeslice")
panic("fail")
}
x := []int{10, 20}
y := []int{99}
i := 1
for i, x[i] = range y {
break
}
if i != 0 || x[0] != 10 || x[1] != 99 {
println("wrong parallel assignment", i, x[0], x[1])
panic("fail")
}
}
func testslice1() {
s := 0
nmake = 0
for i := range makeslice() {
s += i
}
if nmake != 1 {
println("range called makeslice", nmake, "times")
panic("fail")
}
if s != 10 {
println("wrong sum ranging over makeslice")
panic("fail")
}
}
// test that range over array only evaluates
// the expression after "range" once.
func makearray() [5]int {
nmake++
return [5]int{1, 2, 3, 4, 5}
}
func testarray() {
s := 0
nmake = 0
for _, v := range makearray() {
s += v
}
if nmake != 1 {
println("range called makearray", nmake, "times")
panic("fail")
}
if s != 15 {
println("wrong sum ranging over makearray")
panic("fail")
}
}
func testarray1() {
s := 0
nmake = 0
for i := range makearray() {
s += i
}
if nmake != 1 {
println("range called makearray", nmake, "times")
panic("fail")
}
if s != 10 {
println("wrong sum ranging over makearray")
panic("fail")
}
}
func makearrayptr() *[5]int {
nmake++
return &[5]int{1, 2, 3, 4, 5}
}
func testarrayptr() {
nmake = 0
x := len(makearrayptr())
if x != 5 || nmake != 1 {
println("len called makearrayptr", nmake, "times and got len", x)
panic("fail")
}
nmake = 0
x = cap(makearrayptr())
if x != 5 || nmake != 1 {
println("cap called makearrayptr", nmake, "times and got len", x)
panic("fail")
}
s := 0
nmake = 0
for _, v := range makearrayptr() {
s += v
}
if nmake != 1 {
println("range called makearrayptr", nmake, "times")
panic("fail")
}
if s != 15 {
println("wrong sum ranging over makearrayptr")
panic("fail")
}
}
func testarrayptr1() {
s := 0
nmake = 0
for i := range makearrayptr() {
s += i
}
if nmake != 1 {
println("range called makearrayptr", nmake, "times")
panic("fail")
}
if s != 10 {
println("wrong sum ranging over makearrayptr")
panic("fail")
}
}
// test that range over string only evaluates
// the expression after "range" once.
func makestring() string {
nmake++
return "abcd☺"
}
func teststring() {
var s rune
nmake = 0
for _, v := range makestring() {
s += v
}
if nmake != 1 {
println("range called makestring", nmake, "times")
panic("fail")
}
if s != 'a'+'b'+'c'+'d'+'☺' {
println("wrong sum ranging over makestring")
panic("fail")
}
}
func teststring1() {
s := 0
nmake = 0
for i := range makestring() {
s += i
}
if nmake != 1 {
println("range called makestring", nmake, "times")
panic("fail")
}
if s != 10 {
println("wrong sum ranging over makestring")
panic("fail")
}
}
// test that range over map only evaluates
// the expression after "range" once.
func makemap() map[int]int {
nmake++
return map[int]int{0: 'a', 1: 'b', 2: 'c', 3: 'd', 4: '☺'}
}
func testmap() {
s := 0
nmake = 0
for _, v := range makemap() {
s += v
}
if nmake != 1 {
println("range called makemap", nmake, "times")
panic("fail")
}
if s != 'a'+'b'+'c'+'d'+'☺' {
println("wrong sum ranging over makemap")
panic("fail")
}
}
func testmap1() {
s := 0
nmake = 0
for i := range makemap() {
s += i
}
if nmake != 1 {
println("range called makemap", nmake, "times")
panic("fail")
}
if s != 10 {
println("wrong sum ranging over makemap")
panic("fail")
}
}
// test that range evaluates the index and value expressions
// exactly once per iteration.
var ncalls = 0
func getvar(p *int) *int {
ncalls++
return p
}
func testcalls() {
var i, v int
si := 0
sv := 0
for *getvar(&i), *getvar(&v) = range [2]int{1, 2} {
si += i
sv += v
}
if ncalls != 4 {
println("wrong number of calls:", ncalls, "!= 4")
panic("fail")
}
if si != 1 || sv != 3 {
println("wrong sum in testcalls", si, sv)
panic("fail")
}
ncalls = 0
for *getvar(&i), *getvar(&v) = range [0]int{} {
println("loop ran on empty array")
panic("fail")
}
if ncalls != 0 {
println("wrong number of calls:", ncalls, "!= 0")
panic("fail")
}
}
func main() {
testchan()
testarray()
testarray1()
testarrayptr()
testarrayptr1()
testslice()
testslice1()
teststring()
teststring1()
testmap()
testmap1()
testcalls()
}
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