mirror of
https://github.com/unknwon/the-way-to-go_ZH_CN.git
synced 2025-08-12 07:02:11 +08:00
58 lines
1019 B
Go
58 lines
1019 B
Go
package main
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import (
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"fmt"
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)
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type Any interface{}
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type EvalFunc func(Any) (Any, Any)
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func main() {
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evenFunc := func(state Any) (Any, Any) {
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os := state.(int)
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ns := os + 2
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return os, ns
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}
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even := BuildLazyIntEvaluator(evenFunc, 0)
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for i := 0; i < 10; i++ {
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fmt.Printf("%vth even: %v\n", i, even())
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}
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}
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func BuildLazyEvaluator(evalFunc EvalFunc, initState Any) func() Any {
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retValChan := make(chan Any)
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loopFunc := func() {
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var actState Any = initState
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var retVal Any
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for {
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retVal, actState = evalFunc(actState)
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retValChan <- retVal
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}
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}
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retFunc := func() Any {
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return <-retValChan
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}
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go loopFunc()
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return retFunc
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}
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func BuildLazyIntEvaluator(evalFunc EvalFunc, initState Any) func() int {
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ef := BuildLazyEvaluator(evalFunc, initState)
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return func() int {
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return ef().(int)
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}
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}
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/* Output:
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0th even: 0
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1th even: 2
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2th even: 4
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3th even: 6
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4th even: 8
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5th even: 10
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6th even: 12
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7th even: 14
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8th even: 16
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9th even: 18
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*/
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