82be43f4e6
This is a common operation:
freevar := ...
defer func() {
println("I am deferred:", freevar)
}()
The function is thus an immediately applied closure. Only this form is
currently supported, support for regular (fat) function pointers should
be trivial to add but is not currently implemented as it wasn't
necessary to get fmt to compile.
61 строка
1 009 Б
Go
61 строка
1 009 Б
Go
package main
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type Thing struct {
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name string
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}
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func (t Thing) String() string {
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return t.name
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}
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func main() {
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thing := &Thing{"foo"}
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// function pointers
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runFunc(hello, 5) // must be indirect to avoid obvious inlining
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// deferred functions
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testDefer()
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// Take a bound method and use it as a function pointer.
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// This function pointer needs a context pointer.
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testBound(thing.String)
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// closures
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func() {
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println("thing inside closure:", thing.String())
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}()
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runFunc(func(i int) {
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println("inside fp closure:", thing.String(), i)
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}, 3)
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}
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func runFunc(f func(int), arg int) {
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f(arg)
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}
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func hello(n int) {
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println("hello from function pointer:", n)
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}
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func testDefer() {
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i := 1
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defer deferred("...run as defer", i)
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i++
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defer func() {
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println("...run closure deferred:", i)
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}()
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i++
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defer deferred("...run as defer", i)
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i++
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println("deferring...")
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}
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func deferred(msg string, i int) {
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println(msg, i)
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}
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func testBound(f func() string) {
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println("bound method:", f())
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}
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