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31 lines
561 B
Go
31 lines
561 B
Go
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// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 135.
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// The squares program demonstrates a function value with state.
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package main
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import "fmt"
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//!+
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// squares returns a function that returns
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// the next square number each time it is called.
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func squares() func() int {
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var x int
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return func() int {
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x++
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return x * x
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}
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}
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func main() {
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f := squares()
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fmt.Println(f()) // "1"
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fmt.Println(f()) // "4"
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fmt.Println(f()) // "9"
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fmt.Println(f()) // "16"
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}
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//!-
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