godoc: update struct field anchor code
Now without regexps and allocations.
And also match comments like:
// Foo, if non-nil, ...
The comma confused the old pattern.
Updates golang/go#16753
Change-Id: I9016ee7b5933ea343950a39989952804c74a598b
Reviewed-on: https://go-review.googlesource.com/33755
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>
diff --git a/godoc/godoc.go b/godoc/godoc.go
index b8a9d0d..8bda89a 100644
--- a/godoc/godoc.go
+++ b/godoc/godoc.go
@@ -233,49 +233,94 @@
if st.Fields == nil {
return
}
-
- v := buf.Bytes()
- buf.Reset()
-
+ var scratch bytes.Buffer
for _, f := range st.Fields.List {
if len(f.Names) == 0 {
continue
}
fieldName := f.Names[0].Name
- commentStart := []byte("// " + fieldName + " ")
- if bytes.Contains(v, commentStart) {
- // For fields with a doc string of the
- // conventional form, we put the new span into
- // the comment instead of the field.
- // The "conventional" form is a complete sentence
- // per https://golang.org/s/style#comment-sentences like:
- //
- // // Foo is an optional Fooer to foo the foos.
- // Foo Fooer
- //
- // In this case, we want the #StructName.Foo
- // link to make the browser go to the comment
- // line "Foo is an optional Fooer" instead of
- // the "Foo Fooer" line, which could otherwise
- // obscure the docs above the browser's "fold".
- //
- // TODO: do this better, so it works for all
- // comments, including unconventional ones.
- v = bytes.Replace(v, commentStart, []byte(`<span id="`+name+"."+fieldName+`">// `+fieldName+" </span>"), 1)
- } else {
- rx := regexp.MustCompile(`(?m)^\s*` + fieldName + `\b`)
- var matched bool
- v = rx.ReplaceAllFunc(v, func(sub []byte) []byte {
- if matched {
- return sub
- }
- matched = true
- return []byte(`<span id="` + name + "." + fieldName + `">` + string(sub) + "</span>")
- })
+ scratch.Reset()
+ var added bool
+ foreachLine(buf.Bytes(), func(line []byte) {
+ if !added && isLineForStructFieldID(line, fieldName) {
+ added = true
+ fmt.Fprintf(&scratch, `<span id="%s.%s"></span>`, name, fieldName)
+ }
+ scratch.Write(line)
+ })
+ buf.Reset()
+ buf.Write(scratch.Bytes())
+ }
+}
+
+// foreachLine calls fn for each line of in, where a line includes
+// the trailing "\n", except on the last line, if it doesn't exist.
+func foreachLine(in []byte, fn func(line []byte)) {
+ for len(in) > 0 {
+ nl := bytes.IndexByte(in, '\n')
+ if nl == -1 {
+ fn(in)
+ return
+ }
+ fn(in[:nl+1])
+ in = in[nl+1:]
+ }
+}
+
+// commentPrefix is the line prefix for comments after they've been HTMLified.
+var commentPrefix = []byte(`<span class="comment">// `)
+
+// isLineForStructFieldID reports whether line is a line we should
+// add a <span id="#StructName.FieldName"> to. Only the fieldName is provided.
+func isLineForStructFieldID(line []byte, fieldName string) bool {
+ line = bytes.TrimSpace(line)
+
+ // For fields with a doc string of the
+ // conventional form, we put the new span into
+ // the comment instead of the field.
+ // The "conventional" form is a complete sentence
+ // per https://golang.org/s/style#comment-sentences like:
+ //
+ // // Foo is an optional Fooer to foo the foos.
+ // Foo Fooer
+ //
+ // In this case, we want the #StructName.Foo
+ // link to make the browser go to the comment
+ // line "Foo is an optional Fooer" instead of
+ // the "Foo Fooer" line, which could otherwise
+ // obscure the docs above the browser's "fold".
+ //
+ // TODO: do this better, so it works for all
+ // comments, including unconventional ones.
+ // For comments
+ if bytes.HasPrefix(line, commentPrefix) {
+ if matchesIdentBoundary(line[len(commentPrefix):], fieldName) {
+ return true
}
}
+ return matchesIdentBoundary(line, fieldName)
+}
- buf.Write(v)
+// matchesIdentBoundary reports whether line matches /^ident\b/.
+// A boundary is considered either none, or an ASCII non-alphanum.
+func matchesIdentBoundary(line []byte, ident string) bool {
+ if len(line) < len(ident) {
+ return false
+ }
+ if string(line[:len(ident)]) != ident {
+ return false
+ }
+ rest := line[len(ident):]
+ return len(rest) == 0 || !isASCIIWordChar(rest[0])
+}
+
+// isASCIIWordChar reports whether b is an ASCII "word"
+// character. (Matching /\w/ in ASCII mode)
+func isASCIIWordChar(b byte) bool {
+ return 'a' <= b && b <= 'z' ||
+ 'A' <= b && b <= 'Z' ||
+ '0' <= b && b <= '0' ||
+ b == '_'
}
func comment_htmlFunc(comment string) string {
