Go 这是一个int的类型转换器?
我有一本书中的代码示例: Go之路:全面介绍Go编程语言 从中我无法理解某些东西是如何工作的。看看代码:Go 这是一个int的类型转换器?,go,Go,我有一本书中的代码示例: Go之路:全面介绍Go编程语言 从中我无法理解某些东西是如何工作的。看看代码: package main import ( "fmt" ) type Any interface{} type EvalFunc func(Any) (Any, Any) func main() { evenFunc := func(state Any) (Any, Any) { os := state.(int) ns := os +
package main
import (
"fmt"
)
type Any interface{}
type EvalFunc func(Any) (Any, Any)
func main() {
evenFunc := func(state Any) (Any, Any) {
os := state.(int)
ns := os + 2
return os, ns
}
even := BuildLazyIntEvaluator(evenFunc, 0)
for i := 0; i < 10; i++ {
fmt.Printf("%vth even: %v\n", i, even())
}
}
func BuildLazyEvaluator(evalFunc EvalFunc, initState Any) func() Any {
retValChan := make(chan Any)
loopFunc := func() {
var actState Any = initState
var retVal Any
for {
retVal, actState = evalFunc(actState)
retValChan <- retVal
}
}
retFunc := func() Any {
return <-retValChan
}
go loopFunc()
return retFunc
}
func BuildLazyIntEvaluator(evalFunc EvalFunc, initState Any) func() int {
ef := BuildLazyEvaluator(evalFunc, initState)
return func() int {
return ef().(int)
}
}
这里发生了什么事?编译器是否将结果转换为int类型?这是一个类型断言-请参阅。任何接口{}的类型可能重复对初学者来说是一种非常糟糕/令人困惑的方式。我认为,将接口{}称为接口{}。
x := ef() // x is of type Any, which is actually an interface{}
y := x.(int) // this is a type assertion, if the contents of x are an interface, y will be assigned x's int value, otherwise the runtime will panic.
x := ef() // x is of type Any, which is actually an interface{}
y := x.(int) // this is a type assertion, if the contents of x are an interface, y will be assigned x's int value, otherwise the runtime will panic.