mirror of
https://github.com/golang/go
synced 2024-09-05 16:04:50 +00:00
117 lines
1.8 KiB
Go
117 lines
1.8 KiB
Go
// 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 simple type switches, including chans, maps etc.
|
|
|
|
package main
|
|
|
|
import "os"
|
|
|
|
const (
|
|
Bool = iota
|
|
Int
|
|
Float
|
|
String
|
|
Struct
|
|
Chan
|
|
Array
|
|
Map
|
|
Func
|
|
Last
|
|
)
|
|
|
|
type S struct {
|
|
a int
|
|
}
|
|
|
|
var s S = S{1234}
|
|
|
|
var c = make(chan int)
|
|
|
|
var a = []int{0, 1, 2, 3}
|
|
|
|
var m = make(map[string]int)
|
|
|
|
func assert(b bool, s string) {
|
|
if !b {
|
|
println(s)
|
|
os.Exit(1)
|
|
}
|
|
}
|
|
|
|
func f(i int) interface{} {
|
|
switch i {
|
|
case Bool:
|
|
return true
|
|
case Int:
|
|
return 7
|
|
case Float:
|
|
return 7.4
|
|
case String:
|
|
return "hello"
|
|
case Struct:
|
|
return s
|
|
case Chan:
|
|
return c
|
|
case Array:
|
|
return a
|
|
case Map:
|
|
return m
|
|
case Func:
|
|
return f
|
|
}
|
|
panic("bad type number")
|
|
}
|
|
|
|
func main() {
|
|
for i := Bool; i < Last; i++ {
|
|
switch x := f(i).(type) {
|
|
case bool:
|
|
assert(x == true && i == Bool, "bool")
|
|
case int:
|
|
assert(x == 7 && i == Int, "int")
|
|
case float64:
|
|
assert(x == 7.4 && i == Float, "float64")
|
|
case string:
|
|
assert(x == "hello" && i == String, "string")
|
|
case S:
|
|
assert(x.a == 1234 && i == Struct, "struct")
|
|
case chan int:
|
|
assert(x == c && i == Chan, "chan")
|
|
case []int:
|
|
assert(x[3] == 3 && i == Array, "array")
|
|
case map[string]int:
|
|
assert(x != nil && i == Map, "map")
|
|
case func(i int) interface{}:
|
|
assert(x != nil && i == Func, "fun")
|
|
default:
|
|
assert(false, "unknown")
|
|
}
|
|
}
|
|
|
|
// boolean switch (has had bugs in past; worth writing down)
|
|
switch {
|
|
case true:
|
|
assert(true, "switch 2 bool")
|
|
default:
|
|
assert(false, "switch 2 unknown")
|
|
}
|
|
|
|
switch true {
|
|
case true:
|
|
assert(true, "switch 3 bool")
|
|
default:
|
|
assert(false, "switch 3 unknown")
|
|
}
|
|
|
|
switch false {
|
|
case false:
|
|
assert(true, "switch 4 bool")
|
|
default:
|
|
assert(false, "switch 4 unknown")
|
|
}
|
|
}
|