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Diffstat (limited to 'vendor/github.com/russross/blackfriday/v2/inline.go')
| -rw-r--r-- | vendor/github.com/russross/blackfriday/v2/inline.go | 1228 |
1 files changed, 1228 insertions, 0 deletions
diff --git a/vendor/github.com/russross/blackfriday/v2/inline.go b/vendor/github.com/russross/blackfriday/v2/inline.go new file mode 100644 index 000000000..d45bd9417 --- /dev/null +++ b/vendor/github.com/russross/blackfriday/v2/inline.go @@ -0,0 +1,1228 @@ +// +// 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>)`) + + // https://www.w3.org/TR/html5/syntax.html#character-references + // highest unicode code point in 17 planes (2^20): 1,114,112d = + // 7 dec digits or 6 hex digits + // named entity references can be 2-31 characters with stuff like < + // at one end and ∳ at the other. There + // are also sometimes numbers at the end, although this isn't inherent + // in the specification; there are never numbers anywhere else in + // current character references, though; see ¾ and ▒, etc. + // https://www.w3.org/TR/html5/syntax.html#named-character-references + // + // entity := "&" (named group | number ref) ";" + // named group := [a-zA-Z]{2,31}[0-9]{0,2} + // number ref := "#" (dec ref | hex ref) + // dec ref := [0-9]{1,7} + // hex ref := ("x" | "X") [0-9a-fA-F]{1,6} + htmlEntityRe = regexp.MustCompile(`&([a-zA-Z]{2,31}[0-9]{0,2}|#([0-9]{1,7}|[xX][0-9a-fA-F]{1,6}));`) +) + +// 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 *Markdown) inline(currBlock *Node, data []byte) { + // handlers might call us recursively: enforce a maximum depth + if p.nesting >= p.maxNesting || len(data) == 0 { + return + } + p.nesting++ + beg, end := 0, 0 + for end < len(data) { + handler := p.inlineCallback[data[end]] + if handler != nil { + if consumed, node := handler(p, data, end); consumed == 0 { + // No action from the callback. + end++ + } else { + // Copy inactive chars into the output. + currBlock.AppendChild(text(data[beg:end])) + if node != nil { + currBlock.AppendChild(node) + } + // Skip past whatever the callback used. + beg = end + consumed + end = beg + } + } else { + end++ + } + } + if beg < len(data) { + if data[end-1] == '\n' { + end-- + } + currBlock.AppendChild(text(data[beg:end])) + } + p.nesting-- +} + +// single and double emphasis parsing +func emphasis(p *Markdown, data []byte, offset int) (int, *Node) { + data = data[offset:] + c := data[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, nil + } + ret, node := helperEmphasis(p, data[1:], c) + if ret == 0 { + return 0, nil + } + + return ret + 1, node + } + + if len(data) > 3 && data[1] == c && data[2] != c { + if isspace(data[2]) { + return 0, nil + } + ret, node := helperDoubleEmphasis(p, data[2:], c) + if ret == 0 { + return 0, nil + } + + return ret + 2, node + } + + if len(data) > 4 && data[1] == c && data[2] == c && data[3] != c { + if c == '~' || isspace(data[3]) { + return 0, nil + } + ret, node := helperTripleEmphasis(p, data, 3, c) + if ret == 0 { + return 0, nil + } + + return ret + 3, node + } + + return 0, nil +} + +func codeSpan(p *Markdown, data []byte, offset int) (int, *Node) { + 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, nil + } + + // 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 { + code := NewNode(Code) + code.Literal = data[fBegin:fEnd] + return end, code + } + + return end, nil +} + +// newline preceded by two spaces becomes <br> +func maybeLineBreak(p *Markdown, data []byte, offset int) (int, *Node) { + origOffset := offset + for offset < len(data) && data[offset] == ' ' { + offset++ + } + + if offset < len(data) && data[offset] == '\n' { + if offset-origOffset >= 2 { + return offset - origOffset + 1, NewNode(Hardbreak) + } + return offset - origOffset, nil + } + return 0, nil +} + +// newline without two spaces works when HardLineBreak is enabled +func lineBreak(p *Markdown, data []byte, offset int) (int, *Node) { + if p.extensions&HardLineBreak != 0 { + return 1, NewNode(Hardbreak) + } + return 0, nil +} + +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] != '^' +} + +func maybeImage(p *Markdown, data []byte, offset int) (int, *Node) { + if offset < len(data)-1 && data[offset+1] == '[' { + return link(p, data, offset) + } + return 0, nil +} + +func maybeInlineFootnote(p *Markdown, data []byte, offset int) (int, *Node) { + if offset < len(data)-1 && data[offset+1] == '[' { + return link(p, data, offset) + } + return 0, nil +} + +// '[': parse a link or an image or a footnote +func link(p *Markdown, data []byte, offset int) (int, *Node) { + // 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, nil + } + + var t linkType + switch { + // special case: ![^text] == deferred footnote (that follows something with + // an exclamation point) + case p.extensions&Footnotes != 0 && len(data)-1 > offset && data[offset+1] == '^': + t = linkDeferredFootnote + // ![alt] == image + case offset >= 0 && data[offset] == '!': + t = linkImg + offset++ + // ^[text] == inline footnote + // [^refId] == deferred footnote + case p.extensions&Footnotes != 0: + if offset >= 0 && data[offset] == '^' { + t = linkInlineFootnote + offset++ + } 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++ + } + + // look for the matching closing bracket + for level := 1; level > 0 && i < len(data); i++ { + switch { + case data[i] == '\n': + textHasNl = true + + case isBackslashEscaped(data, i): + 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, nil + } + + txtE := i + i++ + var footnoteNode *Node + + // skip any amount of whitespace or newline + // (this is much more lax than original markdown syntax) + for i < len(data) && isspace(data[i]) { + i++ + } + + // inline style link + switch { + case i < len(data) && data[i] == '(': + // skip initial whitespace + i++ + + for i < len(data) && isspace(data[i]) { + i++ + } + + linkB := i + + // look for link end: ' " ) + findlinkend: + for i < len(data) { + switch { + case data[i] == '\\': + i += 2 + + case data[i] == ')' || data[i] == '\'' || data[i] == '"': + break findlinkend + + default: + i++ + } + } + + if i >= len(data) { + return 0, nil + } + 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, nil + } + + // 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, nil + } + 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, nil + } + + // 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] + } + } + + footnoteNode = NewNode(Item) + 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, + footnote: footnoteNode, + } + + p.notes = append(p.notes, ref) + + link = ref.link + title = ref.title + } else { + // find the reference with matching id + lr, ok := p.getRef(string(id)) + if !ok { + return 0, nil + } + + if t == linkDeferredFootnote { + lr.noteID = len(p.notes) + 1 + lr.footnote = footnoteNode + p.notes = append(p.notes, lr) + } + + // 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 + } + + 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 && txtE <= 1) { + return 0, nil + } + } + + // call the relevant rendering function + var linkNode *Node + switch t { + case linkNormal: + linkNode = NewNode(Link) + linkNode.Destination = normalizeURI(uLink) + linkNode.Title = title + if len(altContent) > 0 { + linkNode.AppendChild(text(altContent)) + } else { + // links cannot contain other links, so turn off link parsing + // temporarily and recurse + insideLink := p.insideLink + p.insideLink = true + p.inline(linkNode, data[1:txtE]) + p.insideLink = insideLink + } + + case linkImg: + linkNode = NewNode(Image) + linkNode.Destination = uLink + linkNode.Title = title + linkNode.AppendChild(text(data[1:txtE])) + i++ + + case linkInlineFootnote, linkDeferredFootnote: + linkNode = NewNode(Link) + linkNode.Destination = link + linkNode.Title = title + linkNode.NoteID = noteID + linkNode.Footnote = footnoteNode + if t == linkInlineFootnote { + i++ + } + + default: + return 0, nil + } + + return i, linkNode +} + +func (p *Markdown) inlineHTMLComment(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 +} + +func stripMailto(link []byte) []byte { + if bytes.HasPrefix(link, []byte("mailto://")) { + return link[9:] + } else if bytes.HasPrefix(link, []byte("mailto:")) { + return link[7:] + } else { + return link + } +} + +// autolinkType specifies a kind of autolink that gets detected. +type autolinkType int + +// These are the possible flag values for the autolink renderer. +const ( + notAutolink autolinkType = iota + normalAutolink + emailAutolink +) + +// '<' when tags or autolinks are allowed +func leftAngle(p *Markdown, data []byte, offset int) (int, *Node) { + data = data[offset:] + altype, end := tagLength(data) + if size := p.inlineHTMLComment(data); size > 0 { + end = size + } + if end > 2 { + if altype != notAutolink { + var uLink bytes.Buffer + unescapeText(&uLink, data[1:end+1-2]) + if uLink.Len() > 0 { + link := uLink.Bytes() + node := NewNode(Link) + node.Destination = link + if altype == emailAutolink { + node.Destination = append([]byte("mailto:"), link...) + } + node.AppendChild(text(stripMailto(link))) + return end, node + } + } else { + htmlTag := NewNode(HTMLSpan) + htmlTag.Literal = data[:end] + return end, htmlTag + } + } + + return end, nil +} + +// '\\' backslash escape +var escapeChars = []byte("\\`*_{}[]()#+-.!:|&<>~") + +func escape(p *Markdown, data []byte, offset int) (int, *Node) { + data = data[offset:] + + if len(data) > 1 { + if p.extensions&BackslashLineBreak != 0 && data[1] == '\n' { + return 2, NewNode(Hardbreak) + } + if bytes.IndexByte(escapeChars, data[1]) < 0 { + return 0, nil + } + + return 2, text(data[1:2]) + } + + return 2, nil +} + +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 *Markdown, data []byte, offset int) (int, *Node) { + 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, nil // lone '&' + } + + ent := data[:end] + // undo & escaping or it will be converted to &amp; by another + // escaper in the renderer + if bytes.Equal(ent, []byte("&")) { + ent = []byte{'&'} + } + + return end, text(ent) +} + +func linkEndsWithEntity(data []byte, linkEnd int) bool { + entityRanges := htmlEntityRe.FindAllIndex(data[:linkEnd], -1) + return entityRanges != nil && entityRanges[len(entityRanges)-1][1] == linkEnd +} + +// hasPrefixCaseInsensitive is a custom implementation of +// strings.HasPrefix(strings.ToLower(s), prefix) +// we rolled our own because ToLower pulls in a huge machinery of lowercasing +// anything from Unicode and that's very slow. Since this func will only be +// used on ASCII protocol prefixes, we can take shortcuts. +func hasPrefixCaseInsensitive(s, prefix []byte) bool { + if len(s) < len(prefix) { + return false + } + delta := byte('a' - 'A') + for i, b := range prefix { + if b != s[i] && b != s[i]+delta { + return false + } + } + return true +} + +var protocolPrefixes = [][]byte{ + []byte("http://"), + []byte("https://"), + []byte("ftp://"), + []byte("file://"), + []byte("mailto:"), +} + +const shortestPrefix = 6 // len("ftp://"), the shortest of the above + +func maybeAutoLink(p *Markdown, data []byte, offset int) (int, *Node) { + // quick check to rule out most false hits + if p.insideLink || len(data) < offset+shortestPrefix { + return 0, nil + } + for _, prefix := range protocolPrefixes { + endOfHead := offset + 8 // 8 is the len() of the longest prefix + if endOfHead > len(data) { + endOfHead = len(data) + } + if hasPrefixCaseInsensitive(data[offset:endOfHead], prefix) { + return autoLink(p, data, offset) + } + } + return 0, nil +} + +func autoLink(p *Markdown, data []byte, offset int) (int, *Node) { + // 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 { + anchorClose := NewNode(HTMLSpan) + anchorClose.Literal = anchorStr[offsetFromAnchor:] + return len(anchorStr) - offsetFromAnchor, anchorClose + } + + // 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, nil + } + + origData := data + data = data[offset-rewind:] + + if !isSafeLink(data) { + return 0, nil + } + + 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-- + } + } + + var uLink bytes.Buffer + unescapeText(&uLink, data[:linkEnd]) + + if uLink.Len() > 0 { + node := NewNode(Link) + node.Destination = uLink.Bytes() + node.AppendChild(text(uLink.Bytes())) + return linkEnd, node + } + + return linkEnd, nil +} + +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 autolinkType, end int) { + var i, j int + + // a valid tag can't be shorter than 3 chars + if len(data) < 3 { + return notAutolink, 0 + } + + // begins with a '<' optionally followed by '/', followed by letter or number + if data[0] != '<' { + return notAutolink, 0 + } + if data[1] == '/' { + i = 2 + } else { + i = 1 + } + + if !isalnum(data[i]) { + return notAutolink, 0 + } + + // scheme test + autolink = notAutolink + + // 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 { + return emailAutolink, i + j + } + } + + if i > 2 && i < len(data) && data[i] == ':' { + autolink = normalAutolink + i++ + } + + // complete autolink test: no whitespace or ' or " + switch { + case i >= len(data): + autolink = notAutolink + case autolink != notAutolink: + 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 autolink, 0 + } + if i > j && data[i] == '>' { + return autolink, i + 1 + } + + // one of the forbidden chars has been found + autolink = notAutolink + } + i += bytes.IndexByte(data[i:], '>') + if i < 0 { + return autolink, 0 + } + return autolink, 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 '-', '.', '_': + break + + case '>': + if nb == 1 { + return i + 1 + } + 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 + } + 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 *Markdown, data []byte, c byte) (int, *Node) { + 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, nil + } + i += length + if i >= len(data) { + return 0, nil + } + + if i+1 < len(data) && data[i+1] == c { + i++ + continue + } + + if data[i] == c && !isspace(data[i-1]) { + + if p.extensions&NoIntraEmphasis != 0 { + if !(i+1 == len(data) || isspace(data[i+1]) || ispunct(data[i+1])) { + continue + } + } + + emph := NewNode(Emph) + p.inline(emph, data[:i]) + return i + 1, emph + } + } + + return 0, nil +} + +func helperDoubleEmphasis(p *Markdown, data []byte, c byte) (int, *Node) { + i := 0 + + for i < len(data) { + length := helperFindEmphChar(data[i:], c) + if length == 0 { + return 0, nil + } + i += length + + if i+1 < len(data) && data[i] == c && data[i+1] == c && i > 0 && !isspace(data[i-1]) { + nodeType := Strong + if c == '~' { + nodeType = Del + } + node := NewNode(nodeType) + p.inline(node, data[:i]) + return i + 2, node + } + i++ + } + return 0, nil +} + +func helperTripleEmphasis(p *Markdown, data []byte, offset int, c byte) (int, *Node) { + i := 0 + origData := data + data = data[offset:] + + for i < len(data) { + length := helperFindEmphChar(data[i:], c) + if length == 0 { + return 0, nil + } + 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 + strong := NewNode(Strong) + em := NewNode(Emph) + strong.AppendChild(em) + p.inline(em, data[:i]) + return i + 3, strong + case (i+1 < len(data) && data[i+1] == c): + // double symbol found, hand over to emph1 + length, node := helperEmphasis(p, origData[offset-2:], c) + if length == 0 { + return 0, nil + } + return length - 2, node + default: + // single symbol found, hand over to emph2 + length, node := helperDoubleEmphasis(p, origData[offset-1:], c) + if length == 0 { + return 0, nil + } + return length - 1, node + } + } + return 0, nil +} + +func text(s []byte) *Node { + node := NewNode(Text) + node.Literal = s + return node +} + +func normalizeURI(s []byte) []byte { + return s // TODO: implement +} |