46 lines
1.2 KiB
Go
46 lines
1.2 KiB
Go
// Copyright 2010 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 mime
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import (
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"strings"
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)
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// isTSpecial returns true if rune is in 'tspecials' as defined by RFC
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// 1521 and RFC 2045.
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func isTSpecial(r rune) bool {
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return strings.IndexRune(`()<>@,;:\"/[]?=`, r) != -1
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}
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// IsTokenChar returns true if rune is in 'token' as defined by RFC
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// 1521 and RFC 2045.
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func IsTokenChar(r rune) bool {
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// token := 1*<any (US-ASCII) CHAR except SPACE, CTLs,
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// or tspecials>
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return r > 0x20 && r < 0x7f && !isTSpecial(r)
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}
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// IsToken returns true if s is a 'token' as as defined by RFC 1521
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// and RFC 2045.
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func IsToken(s string) bool {
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if s == "" {
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return false
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}
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return strings.IndexFunc(s, isNotTokenChar) < 0
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}
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// IsQText returns true if rune is in 'qtext' as defined by RFC 822.
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func IsQText(r int) bool {
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// CHAR = <any ASCII character> ; ( 0-177, 0.-127.)
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// qtext = <any CHAR excepting <">, ; => may be folded
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// "\" & CR, and including
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// linear-white-space>
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switch r {
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case '"', '\\', '\r':
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return false
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}
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return r < 0x80
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}
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