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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
commit73df946d56c74384511a194dd01dbe099584fd1a (patch)
treefd0bcea490dd81327ddfbb31e215439672c9a068 /src/go/doc/synopsis.go
parentInitial commit. (diff)
downloadgolang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz
golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/go/doc/synopsis.go')
-rw-r--r--src/go/doc/synopsis.go83
1 files changed, 83 insertions, 0 deletions
diff --git a/src/go/doc/synopsis.go b/src/go/doc/synopsis.go
new file mode 100644
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+++ b/src/go/doc/synopsis.go
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+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package doc
+
+import (
+ "strings"
+ "unicode"
+)
+
+// firstSentenceLen returns the length of the first sentence in s.
+// The sentence ends after the first period followed by space and
+// not preceded by exactly one uppercase letter.
+//
+func firstSentenceLen(s string) int {
+ var ppp, pp, p rune
+ for i, q := range s {
+ if q == '\n' || q == '\r' || q == '\t' {
+ q = ' '
+ }
+ if q == ' ' && p == '.' && (!unicode.IsUpper(pp) || unicode.IsUpper(ppp)) {
+ return i
+ }
+ if p == '。' || p == '.' {
+ return i
+ }
+ ppp, pp, p = pp, p, q
+ }
+ return len(s)
+}
+
+const (
+ keepNL = 1 << iota
+)
+
+// clean replaces each sequence of space, \n, \r, or \t characters
+// with a single space and removes any trailing and leading spaces.
+// If the keepNL flag is set, newline characters are passed through
+// instead of being change to spaces.
+func clean(s string, flags int) string {
+ var b []byte
+ p := byte(' ')
+ for i := 0; i < len(s); i++ {
+ q := s[i]
+ if (flags&keepNL) == 0 && q == '\n' || q == '\r' || q == '\t' {
+ q = ' '
+ }
+ if q != ' ' || p != ' ' {
+ b = append(b, q)
+ p = q
+ }
+ }
+ // remove trailing blank, if any
+ if n := len(b); n > 0 && p == ' ' {
+ b = b[0 : n-1]
+ }
+ return string(b)
+}
+
+// Synopsis returns a cleaned version of the first sentence in s.
+// That sentence ends after the first period followed by space and
+// not preceded by exactly one uppercase letter. The result string
+// has no \n, \r, or \t characters and uses only single spaces between
+// words. If s starts with any of the IllegalPrefixes, the result
+// is the empty string.
+//
+func Synopsis(s string) string {
+ s = clean(s[0:firstSentenceLen(s)], 0)
+ for _, prefix := range IllegalPrefixes {
+ if strings.HasPrefix(strings.ToLower(s), prefix) {
+ return ""
+ }
+ }
+ s = convertQuotes(s)
+ return s
+}
+
+var IllegalPrefixes = []string{
+ "copyright",
+ "all rights",
+ "author",
+}