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zblog/vendor/github.com/russross/blackfriday/v2/esc.go

71 lines
1.3 KiB
Go

package blackfriday
import (
"html"
"io"
)
var htmlEscaper = [256][]byte{
'&': []byte("&"),
'<': []byte("&lt;"),
'>': []byte("&gt;"),
'"': []byte("&quot;"),
}
func escapeHTML(w io.Writer, s []byte) {
escapeEntities(w, s, false)
}
func escapeAllHTML(w io.Writer, s []byte) {
escapeEntities(w, s, true)
}
func escapeEntities(w io.Writer, s []byte, escapeValidEntities bool) {
var start, end int
for end < len(s) {
escSeq := htmlEscaper[s[end]]
if escSeq != nil {
isEntity, entityEnd := nodeIsEntity(s, end)
if isEntity && !escapeValidEntities {
w.Write(s[start : entityEnd+1])
start = entityEnd + 1
} else {
w.Write(s[start:end])
w.Write(escSeq)
start = end + 1
}
}
end++
}
if start < len(s) && end <= len(s) {
w.Write(s[start:end])
}
}
func nodeIsEntity(s []byte, end int) (isEntity bool, endEntityPos int) {
isEntity = false
endEntityPos = end + 1
if s[end] == '&' {
for endEntityPos < len(s) {
if s[endEntityPos] == ';' {
if entities[string(s[end:endEntityPos+1])] {
isEntity = true
break
}
}
if !isalnum(s[endEntityPos]) && s[endEntityPos] != '&' && s[endEntityPos] != '#' {
break
}
endEntityPos++
}
}
return isEntity, endEntityPos
}
func escLink(w io.Writer, text []byte) {
unesc := html.UnescapeString(string(text))
escapeHTML(w, []byte(unesc))
}