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48 lines
924 B
Go
48 lines
924 B
Go
// 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 91.
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//!+nonempty
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// Nonempty is an example of an in-place slice algorithm.
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package main
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import "fmt"
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// nonempty returns a slice holding only the non-empty strings.
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// The underlying array is modified during the call.
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func nonempty(strings []string) []string {
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i := 0
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for _, s := range strings {
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if s != "" {
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strings[i] = s
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i++
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}
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}
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return strings[:i]
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}
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//!-nonempty
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func main() {
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//!+main
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data := []string{"one", "", "three"}
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fmt.Printf("%q\n", nonempty(data)) // `["one" "three"]`
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fmt.Printf("%q\n", data) // `["one" "three" "three"]`
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//!-main
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}
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//!+alt
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func nonempty2(strings []string) []string {
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out := strings[:0] // zero-length slice of original
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for _, s := range strings {
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if s != "" {
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out = append(out, s)
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}
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}
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return out
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}
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//!-alt
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