72 строки
1,2 КиБ
Go
72 строки
1,2 КиБ
Go
package main
|
|
|
|
type Thing struct {
|
|
name string
|
|
}
|
|
|
|
func (t Thing) String() string {
|
|
return t.name
|
|
}
|
|
|
|
func (t Thing) Print(arg string) {
|
|
println("Thing.Print:", t.name, "arg:", arg)
|
|
}
|
|
|
|
type Printer interface {
|
|
Print(string)
|
|
}
|
|
|
|
func main() {
|
|
thing := &Thing{"foo"}
|
|
|
|
// function pointers
|
|
runFunc(hello, 5) // must be indirect to avoid obvious inlining
|
|
|
|
// deferred functions
|
|
testDefer()
|
|
|
|
// Take a bound method and use it as a function pointer.
|
|
// This function pointer needs a context pointer.
|
|
testBound(thing.String)
|
|
|
|
// closures
|
|
func() {
|
|
println("thing inside closure:", thing.String())
|
|
}()
|
|
runFunc(func(i int) {
|
|
println("inside fp closure:", thing.String(), i)
|
|
}, 3)
|
|
}
|
|
|
|
func runFunc(f func(int), arg int) {
|
|
f(arg)
|
|
}
|
|
|
|
func hello(n int) {
|
|
println("hello from function pointer:", n)
|
|
}
|
|
|
|
func testDefer() {
|
|
i := 1
|
|
defer deferred("...run as defer", i)
|
|
i++
|
|
defer func() {
|
|
println("...run closure deferred:", i)
|
|
}()
|
|
i++
|
|
defer deferred("...run as defer", i)
|
|
i++
|
|
|
|
var t Printer = &Thing{"foo"}
|
|
defer t.Print("bar")
|
|
|
|
println("deferring...")
|
|
}
|
|
|
|
func deferred(msg string, i int) {
|
|
println(msg, i)
|
|
}
|
|
|
|
func testBound(f func() string) {
|
|
println("bound method:", f())
|
|
}
|