--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/github.com/russross/blackfriday/inline.go Sun Feb 16 18:54:01 2020 +0100
@@ -0,0 +1,1154 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+// Functions to parse inline elements.
+//
+
+package blackfriday
+
+import (
+ "bytes"
+ "regexp"
+ "strconv"
+)
+
+var (
+ urlRe = `((https?|ftp):\/\/|\/)[-A-Za-z0-9+&@#\/%?=~_|!:,.;\(\)]+`
+ anchorRe = regexp.MustCompile(`^(<a\shref="` + urlRe + `"(\stitle="[^"<>]+")?\s?>` + urlRe + `<\/a>)`)
+)
+
+// Functions to parse text within a block
+// Each function returns the number of chars taken care of
+// data is the complete block being rendered
+// offset is the number of valid chars before the current cursor
+
+func (p *parser) inline(out *bytes.Buffer, data []byte) {
+ // this is called recursively: enforce a maximum depth
+ if p.nesting >= p.maxNesting {
+ return
+ }
+ p.nesting++
+
+ i, end := 0, 0
+ for i < len(data) {
+ // copy inactive chars into the output
+ for end < len(data) && p.inlineCallback[data[end]] == nil {
+ end++
+ }
+
+ p.r.NormalText(out, data[i:end])
+
+ if end >= len(data) {
+ break
+ }
+ i = end
+
+ // call the trigger
+ handler := p.inlineCallback[data[end]]
+ if consumed := handler(p, out, data, i); consumed == 0 {
+ // no action from the callback; buffer the byte for later
+ end = i + 1
+ } else {
+ // skip past whatever the callback used
+ i += consumed
+ end = i
+ }
+ }
+
+ p.nesting--
+}
+
+// single and double emphasis parsing
+func emphasis(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ data = data[offset:]
+ c := data[0]
+ ret := 0
+
+ if len(data) > 2 && data[1] != c {
+ // whitespace cannot follow an opening emphasis;
+ // strikethrough only takes two characters '~~'
+ if c == '~' || isspace(data[1]) {
+ return 0
+ }
+ if ret = helperEmphasis(p, out, data[1:], c); ret == 0 {
+ return 0
+ }
+
+ return ret + 1
+ }
+
+ if len(data) > 3 && data[1] == c && data[2] != c {
+ if isspace(data[2]) {
+ return 0
+ }
+ if ret = helperDoubleEmphasis(p, out, data[2:], c); ret == 0 {
+ return 0
+ }
+
+ return ret + 2
+ }
+
+ if len(data) > 4 && data[1] == c && data[2] == c && data[3] != c {
+ if c == '~' || isspace(data[3]) {
+ return 0
+ }
+ if ret = helperTripleEmphasis(p, out, data, 3, c); ret == 0 {
+ return 0
+ }
+
+ return ret + 3
+ }
+
+ return 0
+}
+
+func codeSpan(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ data = data[offset:]
+
+ nb := 0
+
+ // count the number of backticks in the delimiter
+ for nb < len(data) && data[nb] == '`' {
+ nb++
+ }
+
+ // find the next delimiter
+ i, end := 0, 0
+ for end = nb; end < len(data) && i < nb; end++ {
+ if data[end] == '`' {
+ i++
+ } else {
+ i = 0
+ }
+ }
+
+ // no matching delimiter?
+ if i < nb && end >= len(data) {
+ return 0
+ }
+
+ // trim outside whitespace
+ fBegin := nb
+ for fBegin < end && data[fBegin] == ' ' {
+ fBegin++
+ }
+
+ fEnd := end - nb
+ for fEnd > fBegin && data[fEnd-1] == ' ' {
+ fEnd--
+ }
+
+ // render the code span
+ if fBegin != fEnd {
+ p.r.CodeSpan(out, data[fBegin:fEnd])
+ }
+
+ return end
+
+}
+
+// newline preceded by two spaces becomes <br>
+// newline without two spaces works when EXTENSION_HARD_LINE_BREAK is enabled
+func lineBreak(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ // remove trailing spaces from out
+ outBytes := out.Bytes()
+ end := len(outBytes)
+ eol := end
+ for eol > 0 && outBytes[eol-1] == ' ' {
+ eol--
+ }
+ out.Truncate(eol)
+
+ precededByTwoSpaces := offset >= 2 && data[offset-2] == ' ' && data[offset-1] == ' '
+ precededByBackslash := offset >= 1 && data[offset-1] == '\\' // see http://spec.commonmark.org/0.18/#example-527
+ precededByBackslash = precededByBackslash && p.flags&EXTENSION_BACKSLASH_LINE_BREAK != 0
+
+ if p.flags&EXTENSION_JOIN_LINES != 0 {
+ return 1
+ }
+
+ // should there be a hard line break here?
+ if p.flags&EXTENSION_HARD_LINE_BREAK == 0 && !precededByTwoSpaces && !precededByBackslash {
+ return 0
+ }
+
+ if precededByBackslash && eol > 0 {
+ out.Truncate(eol - 1)
+ }
+ p.r.LineBreak(out)
+ return 1
+}
+
+type linkType int
+
+const (
+ linkNormal linkType = iota
+ linkImg
+ linkDeferredFootnote
+ linkInlineFootnote
+)
+
+func isReferenceStyleLink(data []byte, pos int, t linkType) bool {
+ if t == linkDeferredFootnote {
+ return false
+ }
+ return pos < len(data)-1 && data[pos] == '[' && data[pos+1] != '^'
+}
+
+// '[': parse a link or an image or a footnote
+func link(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ // no links allowed inside regular links, footnote, and deferred footnotes
+ if p.insideLink && (offset > 0 && data[offset-1] == '[' || len(data)-1 > offset && data[offset+1] == '^') {
+ return 0
+ }
+
+ var t linkType
+ switch {
+ // special case: ![^text] == deferred footnote (that follows something with
+ // an exclamation point)
+ case p.flags&EXTENSION_FOOTNOTES != 0 && len(data)-1 > offset && data[offset+1] == '^':
+ t = linkDeferredFootnote
+ // ![alt] == image
+ case offset > 0 && data[offset-1] == '!':
+ t = linkImg
+ // ^[text] == inline footnote
+ // [^refId] == deferred footnote
+ case p.flags&EXTENSION_FOOTNOTES != 0:
+ if offset > 0 && data[offset-1] == '^' {
+ t = linkInlineFootnote
+ } else if len(data)-1 > offset && data[offset+1] == '^' {
+ t = linkDeferredFootnote
+ }
+ // [text] == regular link
+ default:
+ t = linkNormal
+ }
+
+ data = data[offset:]
+
+ var (
+ i = 1
+ noteId int
+ title, link, altContent []byte
+ textHasNl = false
+ )
+
+ if t == linkDeferredFootnote {
+ i++
+ }
+
+ brace := 0
+
+ // look for the matching closing bracket
+ for level := 1; level > 0 && i < len(data); i++ {
+ switch {
+ case data[i] == '\n':
+ textHasNl = true
+
+ case data[i-1] == '\\':
+ continue
+
+ case data[i] == '[':
+ level++
+
+ case data[i] == ']':
+ level--
+ if level <= 0 {
+ i-- // compensate for extra i++ in for loop
+ }
+ }
+ }
+
+ if i >= len(data) {
+ return 0
+ }
+
+ txtE := i
+ i++
+
+ // skip any amount of whitespace or newline
+ // (this is much more lax than original markdown syntax)
+ for i < len(data) && isspace(data[i]) {
+ i++
+ }
+
+ switch {
+ // inline style link
+ case i < len(data) && data[i] == '(':
+ // skip initial whitespace
+ i++
+
+ for i < len(data) && isspace(data[i]) {
+ i++
+ }
+
+ linkB := i
+
+ // look for link end: ' " ), check for new opening braces and take this
+ // into account, this may lead for overshooting and probably will require
+ // some fine-tuning.
+ findlinkend:
+ for i < len(data) {
+ switch {
+ case data[i] == '\\':
+ i += 2
+
+ case data[i] == '(':
+ brace++
+ i++
+
+ case data[i] == ')':
+ if brace <= 0 {
+ break findlinkend
+ }
+ brace--
+ i++
+
+ case data[i] == '\'' || data[i] == '"':
+ break findlinkend
+
+ default:
+ i++
+ }
+ }
+
+ if i >= len(data) {
+ return 0
+ }
+ linkE := i
+
+ // look for title end if present
+ titleB, titleE := 0, 0
+ if data[i] == '\'' || data[i] == '"' {
+ i++
+ titleB = i
+
+ findtitleend:
+ for i < len(data) {
+ switch {
+ case data[i] == '\\':
+ i += 2
+
+ case data[i] == ')':
+ break findtitleend
+
+ default:
+ i++
+ }
+ }
+
+ if i >= len(data) {
+ return 0
+ }
+
+ // skip whitespace after title
+ titleE = i - 1
+ for titleE > titleB && isspace(data[titleE]) {
+ titleE--
+ }
+
+ // check for closing quote presence
+ if data[titleE] != '\'' && data[titleE] != '"' {
+ titleB, titleE = 0, 0
+ linkE = i
+ }
+ }
+
+ // remove whitespace at the end of the link
+ for linkE > linkB && isspace(data[linkE-1]) {
+ linkE--
+ }
+
+ // remove optional angle brackets around the link
+ if data[linkB] == '<' {
+ linkB++
+ }
+ if data[linkE-1] == '>' {
+ linkE--
+ }
+
+ // build escaped link and title
+ if linkE > linkB {
+ link = data[linkB:linkE]
+ }
+
+ if titleE > titleB {
+ title = data[titleB:titleE]
+ }
+
+ i++
+
+ // reference style link
+ case isReferenceStyleLink(data, i, t):
+ var id []byte
+ altContentConsidered := false
+
+ // look for the id
+ i++
+ linkB := i
+ for i < len(data) && data[i] != ']' {
+ i++
+ }
+ if i >= len(data) {
+ return 0
+ }
+ linkE := i
+
+ // find the reference
+ if linkB == linkE {
+ if textHasNl {
+ var b bytes.Buffer
+
+ for j := 1; j < txtE; j++ {
+ switch {
+ case data[j] != '\n':
+ b.WriteByte(data[j])
+ case data[j-1] != ' ':
+ b.WriteByte(' ')
+ }
+ }
+
+ id = b.Bytes()
+ } else {
+ id = data[1:txtE]
+ altContentConsidered = true
+ }
+ } else {
+ id = data[linkB:linkE]
+ }
+
+ // find the reference with matching id
+ lr, ok := p.getRef(string(id))
+ if !ok {
+ return 0
+ }
+
+ // keep link and title from reference
+ link = lr.link
+ title = lr.title
+ if altContentConsidered {
+ altContent = lr.text
+ }
+ i++
+
+ // shortcut reference style link or reference or inline footnote
+ default:
+ var id []byte
+
+ // craft the id
+ if textHasNl {
+ var b bytes.Buffer
+
+ for j := 1; j < txtE; j++ {
+ switch {
+ case data[j] != '\n':
+ b.WriteByte(data[j])
+ case data[j-1] != ' ':
+ b.WriteByte(' ')
+ }
+ }
+
+ id = b.Bytes()
+ } else {
+ if t == linkDeferredFootnote {
+ id = data[2:txtE] // get rid of the ^
+ } else {
+ id = data[1:txtE]
+ }
+ }
+
+ if t == linkInlineFootnote {
+ // create a new reference
+ noteId = len(p.notes) + 1
+
+ var fragment []byte
+ if len(id) > 0 {
+ if len(id) < 16 {
+ fragment = make([]byte, len(id))
+ } else {
+ fragment = make([]byte, 16)
+ }
+ copy(fragment, slugify(id))
+ } else {
+ fragment = append([]byte("footnote-"), []byte(strconv.Itoa(noteId))...)
+ }
+
+ ref := &reference{
+ noteId: noteId,
+ hasBlock: false,
+ link: fragment,
+ title: id,
+ }
+
+ p.notes = append(p.notes, ref)
+ p.notesRecord[string(ref.link)] = struct{}{}
+
+ link = ref.link
+ title = ref.title
+ } else {
+ // find the reference with matching id
+ lr, ok := p.getRef(string(id))
+ if !ok {
+ return 0
+ }
+
+ if t == linkDeferredFootnote && !p.isFootnote(lr) {
+ lr.noteId = len(p.notes) + 1
+ p.notes = append(p.notes, lr)
+ p.notesRecord[string(lr.link)] = struct{}{}
+ }
+
+ // keep link and title from reference
+ link = lr.link
+ // if inline footnote, title == footnote contents
+ title = lr.title
+ noteId = lr.noteId
+ }
+
+ // rewind the whitespace
+ i = txtE + 1
+ }
+
+ // build content: img alt is escaped, link content is parsed
+ var content bytes.Buffer
+ if txtE > 1 {
+ if t == linkImg {
+ content.Write(data[1:txtE])
+ } else {
+ // links cannot contain other links, so turn off link parsing temporarily
+ insideLink := p.insideLink
+ p.insideLink = true
+ p.inline(&content, data[1:txtE])
+ p.insideLink = insideLink
+ }
+ }
+
+ var uLink []byte
+ if t == linkNormal || t == linkImg {
+ if len(link) > 0 {
+ var uLinkBuf bytes.Buffer
+ unescapeText(&uLinkBuf, link)
+ uLink = uLinkBuf.Bytes()
+ }
+
+ // links need something to click on and somewhere to go
+ if len(uLink) == 0 || (t == linkNormal && content.Len() == 0) {
+ return 0
+ }
+ }
+
+ // call the relevant rendering function
+ switch t {
+ case linkNormal:
+ if len(altContent) > 0 {
+ p.r.Link(out, uLink, title, altContent)
+ } else {
+ p.r.Link(out, uLink, title, content.Bytes())
+ }
+
+ case linkImg:
+ outSize := out.Len()
+ outBytes := out.Bytes()
+ if outSize > 0 && outBytes[outSize-1] == '!' {
+ out.Truncate(outSize - 1)
+ }
+
+ p.r.Image(out, uLink, title, content.Bytes())
+
+ case linkInlineFootnote:
+ outSize := out.Len()
+ outBytes := out.Bytes()
+ if outSize > 0 && outBytes[outSize-1] == '^' {
+ out.Truncate(outSize - 1)
+ }
+
+ p.r.FootnoteRef(out, link, noteId)
+
+ case linkDeferredFootnote:
+ p.r.FootnoteRef(out, link, noteId)
+
+ default:
+ return 0
+ }
+
+ return i
+}
+
+func (p *parser) inlineHTMLComment(out *bytes.Buffer, data []byte) int {
+ if len(data) < 5 {
+ return 0
+ }
+ if data[0] != '<' || data[1] != '!' || data[2] != '-' || data[3] != '-' {
+ return 0
+ }
+ i := 5
+ // scan for an end-of-comment marker, across lines if necessary
+ for i < len(data) && !(data[i-2] == '-' && data[i-1] == '-' && data[i] == '>') {
+ i++
+ }
+ // no end-of-comment marker
+ if i >= len(data) {
+ return 0
+ }
+ return i + 1
+}
+
+// '<' when tags or autolinks are allowed
+func leftAngle(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ data = data[offset:]
+ altype := LINK_TYPE_NOT_AUTOLINK
+ end := tagLength(data, &altype)
+ if size := p.inlineHTMLComment(out, data); size > 0 {
+ end = size
+ }
+ if end > 2 {
+ if altype != LINK_TYPE_NOT_AUTOLINK {
+ var uLink bytes.Buffer
+ unescapeText(&uLink, data[1:end+1-2])
+ if uLink.Len() > 0 {
+ p.r.AutoLink(out, uLink.Bytes(), altype)
+ }
+ } else {
+ p.r.RawHtmlTag(out, data[:end])
+ }
+ }
+
+ return end
+}
+
+// '\\' backslash escape
+var escapeChars = []byte("\\`*_{}[]()#+-.!:|&<>~")
+
+func escape(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ data = data[offset:]
+
+ if len(data) > 1 {
+ if bytes.IndexByte(escapeChars, data[1]) < 0 {
+ return 0
+ }
+
+ p.r.NormalText(out, data[1:2])
+ }
+
+ return 2
+}
+
+func unescapeText(ob *bytes.Buffer, src []byte) {
+ i := 0
+ for i < len(src) {
+ org := i
+ for i < len(src) && src[i] != '\\' {
+ i++
+ }
+
+ if i > org {
+ ob.Write(src[org:i])
+ }
+
+ if i+1 >= len(src) {
+ break
+ }
+
+ ob.WriteByte(src[i+1])
+ i += 2
+ }
+}
+
+// '&' escaped when it doesn't belong to an entity
+// valid entities are assumed to be anything matching &#?[A-Za-z0-9]+;
+func entity(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ data = data[offset:]
+
+ end := 1
+
+ if end < len(data) && data[end] == '#' {
+ end++
+ }
+
+ for end < len(data) && isalnum(data[end]) {
+ end++
+ }
+
+ if end < len(data) && data[end] == ';' {
+ end++ // real entity
+ } else {
+ return 0 // lone '&'
+ }
+
+ p.r.Entity(out, data[:end])
+
+ return end
+}
+
+func linkEndsWithEntity(data []byte, linkEnd int) bool {
+ entityRanges := htmlEntity.FindAllIndex(data[:linkEnd], -1)
+ return entityRanges != nil && entityRanges[len(entityRanges)-1][1] == linkEnd
+}
+
+func autoLink(p *parser, out *bytes.Buffer, data []byte, offset int) int {
+ // quick check to rule out most false hits on ':'
+ if p.insideLink || len(data) < offset+3 || data[offset+1] != '/' || data[offset+2] != '/' {
+ return 0
+ }
+
+ // Now a more expensive check to see if we're not inside an anchor element
+ anchorStart := offset
+ offsetFromAnchor := 0
+ for anchorStart > 0 && data[anchorStart] != '<' {
+ anchorStart--
+ offsetFromAnchor++
+ }
+
+ anchorStr := anchorRe.Find(data[anchorStart:])
+ if anchorStr != nil {
+ out.Write(anchorStr[offsetFromAnchor:])
+ return len(anchorStr) - offsetFromAnchor
+ }
+
+ // scan backward for a word boundary
+ rewind := 0
+ for offset-rewind > 0 && rewind <= 7 && isletter(data[offset-rewind-1]) {
+ rewind++
+ }
+ if rewind > 6 { // longest supported protocol is "mailto" which has 6 letters
+ return 0
+ }
+
+ origData := data
+ data = data[offset-rewind:]
+
+ if !isSafeLink(data) {
+ return 0
+ }
+
+ linkEnd := 0
+ for linkEnd < len(data) && !isEndOfLink(data[linkEnd]) {
+ linkEnd++
+ }
+
+ // Skip punctuation at the end of the link
+ if (data[linkEnd-1] == '.' || data[linkEnd-1] == ',') && data[linkEnd-2] != '\\' {
+ linkEnd--
+ }
+
+ // But don't skip semicolon if it's a part of escaped entity:
+ if data[linkEnd-1] == ';' && data[linkEnd-2] != '\\' && !linkEndsWithEntity(data, linkEnd) {
+ linkEnd--
+ }
+
+ // See if the link finishes with a punctuation sign that can be closed.
+ var copen byte
+ switch data[linkEnd-1] {
+ case '"':
+ copen = '"'
+ case '\'':
+ copen = '\''
+ case ')':
+ copen = '('
+ case ']':
+ copen = '['
+ case '}':
+ copen = '{'
+ default:
+ copen = 0
+ }
+
+ if copen != 0 {
+ bufEnd := offset - rewind + linkEnd - 2
+
+ openDelim := 1
+
+ /* Try to close the final punctuation sign in this same line;
+ * if we managed to close it outside of the URL, that means that it's
+ * not part of the URL. If it closes inside the URL, that means it
+ * is part of the URL.
+ *
+ * Examples:
+ *
+ * foo http://www.pokemon.com/Pikachu_(Electric) bar
+ * => http://www.pokemon.com/Pikachu_(Electric)
+ *
+ * foo (http://www.pokemon.com/Pikachu_(Electric)) bar
+ * => http://www.pokemon.com/Pikachu_(Electric)
+ *
+ * foo http://www.pokemon.com/Pikachu_(Electric)) bar
+ * => http://www.pokemon.com/Pikachu_(Electric))
+ *
+ * (foo http://www.pokemon.com/Pikachu_(Electric)) bar
+ * => foo http://www.pokemon.com/Pikachu_(Electric)
+ */
+
+ for bufEnd >= 0 && origData[bufEnd] != '\n' && openDelim != 0 {
+ if origData[bufEnd] == data[linkEnd-1] {
+ openDelim++
+ }
+
+ if origData[bufEnd] == copen {
+ openDelim--
+ }
+
+ bufEnd--
+ }
+
+ if openDelim == 0 {
+ linkEnd--
+ }
+ }
+
+ // we were triggered on the ':', so we need to rewind the output a bit
+ if out.Len() >= rewind {
+ out.Truncate(len(out.Bytes()) - rewind)
+ }
+
+ var uLink bytes.Buffer
+ unescapeText(&uLink, data[:linkEnd])
+
+ if uLink.Len() > 0 {
+ p.r.AutoLink(out, uLink.Bytes(), LINK_TYPE_NORMAL)
+ }
+
+ return linkEnd - rewind
+}
+
+func isEndOfLink(char byte) bool {
+ return isspace(char) || char == '<'
+}
+
+var validUris = [][]byte{[]byte("http://"), []byte("https://"), []byte("ftp://"), []byte("mailto://")}
+var validPaths = [][]byte{[]byte("/"), []byte("./"), []byte("../")}
+
+func isSafeLink(link []byte) bool {
+ for _, path := range validPaths {
+ if len(link) >= len(path) && bytes.Equal(link[:len(path)], path) {
+ if len(link) == len(path) {
+ return true
+ } else if isalnum(link[len(path)]) {
+ return true
+ }
+ }
+ }
+
+ for _, prefix := range validUris {
+ // TODO: handle unicode here
+ // case-insensitive prefix test
+ if len(link) > len(prefix) && bytes.Equal(bytes.ToLower(link[:len(prefix)]), prefix) && isalnum(link[len(prefix)]) {
+ return true
+ }
+ }
+
+ return false
+}
+
+// return the length of the given tag, or 0 is it's not valid
+func tagLength(data []byte, autolink *int) int {
+ var i, j int
+
+ // a valid tag can't be shorter than 3 chars
+ if len(data) < 3 {
+ return 0
+ }
+
+ // begins with a '<' optionally followed by '/', followed by letter or number
+ if data[0] != '<' {
+ return 0
+ }
+ if data[1] == '/' {
+ i = 2
+ } else {
+ i = 1
+ }
+
+ if !isalnum(data[i]) {
+ return 0
+ }
+
+ // scheme test
+ *autolink = LINK_TYPE_NOT_AUTOLINK
+
+ // try to find the beginning of an URI
+ for i < len(data) && (isalnum(data[i]) || data[i] == '.' || data[i] == '+' || data[i] == '-') {
+ i++
+ }
+
+ if i > 1 && i < len(data) && data[i] == '@' {
+ if j = isMailtoAutoLink(data[i:]); j != 0 {
+ *autolink = LINK_TYPE_EMAIL
+ return i + j
+ }
+ }
+
+ if i > 2 && i < len(data) && data[i] == ':' {
+ *autolink = LINK_TYPE_NORMAL
+ i++
+ }
+
+ // complete autolink test: no whitespace or ' or "
+ switch {
+ case i >= len(data):
+ *autolink = LINK_TYPE_NOT_AUTOLINK
+ case *autolink != 0:
+ j = i
+
+ for i < len(data) {
+ if data[i] == '\\' {
+ i += 2
+ } else if data[i] == '>' || data[i] == '\'' || data[i] == '"' || isspace(data[i]) {
+ break
+ } else {
+ i++
+ }
+
+ }
+
+ if i >= len(data) {
+ return 0
+ }
+ if i > j && data[i] == '>' {
+ return i + 1
+ }
+
+ // one of the forbidden chars has been found
+ *autolink = LINK_TYPE_NOT_AUTOLINK
+ }
+
+ // look for something looking like a tag end
+ for i < len(data) && data[i] != '>' {
+ i++
+ }
+ if i >= len(data) {
+ return 0
+ }
+ return i + 1
+}
+
+// look for the address part of a mail autolink and '>'
+// this is less strict than the original markdown e-mail address matching
+func isMailtoAutoLink(data []byte) int {
+ nb := 0
+
+ // address is assumed to be: [-@._a-zA-Z0-9]+ with exactly one '@'
+ for i := 0; i < len(data); i++ {
+ if isalnum(data[i]) {
+ continue
+ }
+
+ switch data[i] {
+ case '@':
+ nb++
+
+ case '-', '.', '_':
+ // Do nothing.
+
+ case '>':
+ if nb == 1 {
+ return i + 1
+ } else {
+ return 0
+ }
+ default:
+ return 0
+ }
+ }
+
+ return 0
+}
+
+// look for the next emph char, skipping other constructs
+func helperFindEmphChar(data []byte, c byte) int {
+ i := 0
+
+ for i < len(data) {
+ for i < len(data) && data[i] != c && data[i] != '`' && data[i] != '[' {
+ i++
+ }
+ if i >= len(data) {
+ return 0
+ }
+ // do not count escaped chars
+ if i != 0 && data[i-1] == '\\' {
+ i++
+ continue
+ }
+ if data[i] == c {
+ return i
+ }
+
+ if data[i] == '`' {
+ // skip a code span
+ tmpI := 0
+ i++
+ for i < len(data) && data[i] != '`' {
+ if tmpI == 0 && data[i] == c {
+ tmpI = i
+ }
+ i++
+ }
+ if i >= len(data) {
+ return tmpI
+ }
+ i++
+ } else if data[i] == '[' {
+ // skip a link
+ tmpI := 0
+ i++
+ for i < len(data) && data[i] != ']' {
+ if tmpI == 0 && data[i] == c {
+ tmpI = i
+ }
+ i++
+ }
+ i++
+ for i < len(data) && (data[i] == ' ' || data[i] == '\n') {
+ i++
+ }
+ if i >= len(data) {
+ return tmpI
+ }
+ if data[i] != '[' && data[i] != '(' { // not a link
+ if tmpI > 0 {
+ return tmpI
+ } else {
+ continue
+ }
+ }
+ cc := data[i]
+ i++
+ for i < len(data) && data[i] != cc {
+ if tmpI == 0 && data[i] == c {
+ return i
+ }
+ i++
+ }
+ if i >= len(data) {
+ return tmpI
+ }
+ i++
+ }
+ }
+ return 0
+}
+
+func helperEmphasis(p *parser, out *bytes.Buffer, data []byte, c byte) int {
+ i := 0
+
+ // skip one symbol if coming from emph3
+ if len(data) > 1 && data[0] == c && data[1] == c {
+ i = 1
+ }
+
+ for i < len(data) {
+ length := helperFindEmphChar(data[i:], c)
+ if length == 0 {
+ return 0
+ }
+ i += length
+ if i >= len(data) {
+ return 0
+ }
+
+ if i+1 < len(data) && data[i+1] == c {
+ i++
+ continue
+ }
+
+ if data[i] == c && !isspace(data[i-1]) {
+
+ if p.flags&EXTENSION_NO_INTRA_EMPHASIS != 0 {
+ if !(i+1 == len(data) || isspace(data[i+1]) || ispunct(data[i+1])) {
+ continue
+ }
+ }
+
+ var work bytes.Buffer
+ p.inline(&work, data[:i])
+ p.r.Emphasis(out, work.Bytes())
+ return i + 1
+ }
+ }
+
+ return 0
+}
+
+func helperDoubleEmphasis(p *parser, out *bytes.Buffer, data []byte, c byte) int {
+ i := 0
+
+ for i < len(data) {
+ length := helperFindEmphChar(data[i:], c)
+ if length == 0 {
+ return 0
+ }
+ i += length
+
+ if i+1 < len(data) && data[i] == c && data[i+1] == c && i > 0 && !isspace(data[i-1]) {
+ var work bytes.Buffer
+ p.inline(&work, data[:i])
+
+ if work.Len() > 0 {
+ // pick the right renderer
+ if c == '~' {
+ p.r.StrikeThrough(out, work.Bytes())
+ } else {
+ p.r.DoubleEmphasis(out, work.Bytes())
+ }
+ }
+ return i + 2
+ }
+ i++
+ }
+ return 0
+}
+
+func helperTripleEmphasis(p *parser, out *bytes.Buffer, data []byte, offset int, c byte) int {
+ i := 0
+ origData := data
+ data = data[offset:]
+
+ for i < len(data) {
+ length := helperFindEmphChar(data[i:], c)
+ if length == 0 {
+ return 0
+ }
+ i += length
+
+ // skip whitespace preceded symbols
+ if data[i] != c || isspace(data[i-1]) {
+ continue
+ }
+
+ switch {
+ case i+2 < len(data) && data[i+1] == c && data[i+2] == c:
+ // triple symbol found
+ var work bytes.Buffer
+
+ p.inline(&work, data[:i])
+ if work.Len() > 0 {
+ p.r.TripleEmphasis(out, work.Bytes())
+ }
+ return i + 3
+ case (i+1 < len(data) && data[i+1] == c):
+ // double symbol found, hand over to emph1
+ length = helperEmphasis(p, out, origData[offset-2:], c)
+ if length == 0 {
+ return 0
+ } else {
+ return length - 2
+ }
+ default:
+ // single symbol found, hand over to emph2
+ length = helperDoubleEmphasis(p, out, origData[offset-1:], c)
+ if length == 0 {
+ return 0
+ } else {
+ return length - 1
+ }
+ }
+ }
+ return 0
+}