mirror of
https://github.com/autc04/Retro68.git
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62 lines
1.2 KiB
Go
62 lines
1.2 KiB
Go
// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package ascii
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import (
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"strings"
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"unicode"
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)
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// EqualFold is strings.EqualFold, ASCII only. It reports whether s and t
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// are equal, ASCII-case-insensitively.
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func EqualFold(s, t string) bool {
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if len(s) != len(t) {
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return false
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}
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for i := 0; i < len(s); i++ {
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if lower(s[i]) != lower(t[i]) {
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return false
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}
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}
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return true
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}
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// lower returns the ASCII lowercase version of b.
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func lower(b byte) byte {
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if 'A' <= b && b <= 'Z' {
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return b + ('a' - 'A')
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}
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return b
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}
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// IsPrint returns whether s is ASCII and printable according to
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// https://tools.ietf.org/html/rfc20#section-4.2.
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func IsPrint(s string) bool {
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for i := 0; i < len(s); i++ {
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if s[i] < ' ' || s[i] > '~' {
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return false
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}
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}
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return true
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}
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// Is returns whether s is ASCII.
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func Is(s string) bool {
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for i := 0; i < len(s); i++ {
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if s[i] > unicode.MaxASCII {
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return false
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}
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}
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return true
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}
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// ToLower returns the lowercase version of s if s is ASCII and printable.
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func ToLower(s string) (lower string, ok bool) {
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if !IsPrint(s) {
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return "", false
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}
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return strings.ToLower(s), true
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}
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