发现一段非常好的惰性生成器代码+个人学习笔记

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)
    }
}

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原文作者：Go  LearnKu  

　　

 

 

 

其中的闭包调用关系不太好理解自己花了一个图