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Diffstat (limited to 'js/lib/inlines.js')
| -rw-r--r-- | js/lib/inlines.js | 739 |
1 files changed, 739 insertions, 0 deletions
diff --git a/js/lib/inlines.js b/js/lib/inlines.js new file mode 100644 index 0000000..0e79556 --- /dev/null +++ b/js/lib/inlines.js @@ -0,0 +1,739 @@ +var fromCodePoint = require('./from-code-point.js'); +var entityToChar = require('./html5-entities.js').entityToChar; + +// Constants for character codes: + +var C_NEWLINE = 10; +var C_SPACE = 32; +var C_ASTERISK = 42; +var C_UNDERSCORE = 95; +var C_BACKTICK = 96; +var C_OPEN_BRACKET = 91; +var C_CLOSE_BRACKET = 93; +var C_LESSTHAN = 60; +var C_GREATERTHAN = 62; +var C_BANG = 33; +var C_BACKSLASH = 92; +var C_AMPERSAND = 38; +var C_OPEN_PAREN = 40; +var C_COLON = 58; + +// Some regexps used in inline parser: + +var ESCAPABLE = '[!"#$%&\'()*+,./:;<=>?@[\\\\\\]^_`{|}~-]'; +var ESCAPED_CHAR = '\\\\' + ESCAPABLE; +var IN_DOUBLE_QUOTES = '"(' + ESCAPED_CHAR + '|[^"\\x00])*"'; +var IN_SINGLE_QUOTES = '\'(' + ESCAPED_CHAR + '|[^\'\\x00])*\''; +var IN_PARENS = '\\((' + ESCAPED_CHAR + '|[^)\\x00])*\\)'; +var REG_CHAR = '[^\\\\()\\x00-\\x20]'; +var IN_PARENS_NOSP = '\\((' + REG_CHAR + '|' + ESCAPED_CHAR + ')*\\)'; +var TAGNAME = '[A-Za-z][A-Za-z0-9]*'; +var ATTRIBUTENAME = '[a-zA-Z_:][a-zA-Z0-9:._-]*'; +var UNQUOTEDVALUE = "[^\"'=<>`\\x00-\\x20]+"; +var SINGLEQUOTEDVALUE = "'[^']*'"; +var DOUBLEQUOTEDVALUE = '"[^"]*"'; +var ATTRIBUTEVALUE = "(?:" + UNQUOTEDVALUE + "|" + SINGLEQUOTEDVALUE + "|" + DOUBLEQUOTEDVALUE + ")"; +var ATTRIBUTEVALUESPEC = "(?:" + "\\s*=" + "\\s*" + ATTRIBUTEVALUE + ")"; +var ATTRIBUTE = "(?:" + "\\s+" + ATTRIBUTENAME + ATTRIBUTEVALUESPEC + "?)"; +var OPENTAG = "<" + TAGNAME + ATTRIBUTE + "*" + "\\s*/?>"; +var CLOSETAG = "</" + TAGNAME + "\\s*[>]"; +var HTMLCOMMENT = "<!--([^-]+|[-][^-]+)*-->"; +var PROCESSINGINSTRUCTION = "[<][?].*?[?][>]"; +var DECLARATION = "<![A-Z]+" + "\\s+[^>]*>"; +var CDATA = "<!\\[CDATA\\[([^\\]]+|\\][^\\]]|\\]\\][^>])*\\]\\]>"; +var HTMLTAG = "(?:" + OPENTAG + "|" + CLOSETAG + "|" + HTMLCOMMENT + "|" + + PROCESSINGINSTRUCTION + "|" + DECLARATION + "|" + CDATA + ")"; +var ENTITY = "&(?:#x[a-f0-9]{1,8}|#[0-9]{1,8}|[a-z][a-z0-9]{1,31});"; + +var reHtmlTag = new RegExp('^' + HTMLTAG, 'i'); + +var reLinkTitle = new RegExp( + '^(?:"(' + ESCAPED_CHAR + '|[^"\\x00])*"' + + '|' + + '\'(' + ESCAPED_CHAR + '|[^\'\\x00])*\'' + + '|' + + '\\((' + ESCAPED_CHAR + '|[^)\\x00])*\\))'); + +var reLinkDestinationBraces = new RegExp( + '^(?:[<](?:[^<>\\n\\\\\\x00]' + '|' + ESCAPED_CHAR + '|' + '\\\\)*[>])'); + +var reLinkDestination = new RegExp( + '^(?:' + REG_CHAR + '+|' + ESCAPED_CHAR + '|' + IN_PARENS_NOSP + ')*'); + +var reEscapable = new RegExp(ESCAPABLE); + +var reAllEscapedChar = new RegExp('\\\\(' + ESCAPABLE + ')', 'g'); + +var reEscapedChar = new RegExp('^\\\\(' + ESCAPABLE + ')'); + +var reEntityHere = new RegExp('^' + ENTITY, 'i'); + +var reEntity = new RegExp(ENTITY, 'gi'); + +// Matches a character with a special meaning in markdown, +// or a string of non-special characters. Note: we match +// clumps of _ or * or `, because they need to be handled in groups. +var reMain = /^(?:[_*`\n]+|[\[\]\\!<&*_]|(?: *[^\n `\[\]\\!<&*_]+)+|[ \n]+)/m; + +// Replace entities and backslash escapes with literal characters. +var unescapeEntBS = function(s) { + return s.replace(reAllEscapedChar, '$1') + .replace(reEntity, entityToChar); +}; + +// Normalize reference label: collapse internal whitespace +// to single space, remove leading/trailing whitespace, case fold. +var normalizeReference = function(s) { + return s.trim() + .replace(/\s+/,' ') + .toUpperCase(); +}; + +// INLINE PARSER + +// These are methods of an InlineParser object, defined below. +// An InlineParser keeps track of a subject (a string to be +// parsed) and a position in that subject. + +// If re matches at current position in the subject, advance +// position in subject and return the match; otherwise return null. +var match = function(re) { + var match = re.exec(this.subject.slice(this.pos)); + if (match) { + this.pos += match.index + match[0].length; + return match[0]; + } else { + return null; + } +}; + +// Returns the code for the character at the current subject position, or -1 +// there are no more characters. +var peek = function() { + if (this.pos < this.subject.length) { + return this.subject.charCodeAt(this.pos); + } else { + return -1; + } +}; + +// Parse zero or more space characters, including at most one newline +var spnl = function() { + this.match(/^ *(?:\n *)?/); + return 1; +}; + +// All of the parsers below try to match something at the current position +// in the subject. If they succeed in matching anything, they +// return the inline matched, advancing the subject. + +// Attempt to parse backticks, returning either a backtick code span or a +// literal sequence of backticks. +var parseBackticks = function(inlines) { + var startpos = this.pos; + var ticks = this.match(/^`+/); + if (!ticks) { + return 0; + } + var afterOpenTicks = this.pos; + var foundCode = false; + var match; + while (!foundCode && (match = this.match(/`+/m))) { + if (match == ticks) { + inlines.push({ t: 'Code', c: this.subject.slice(afterOpenTicks, + this.pos - ticks.length) + .replace(/[ \n]+/g,' ') + .trim() }); + return true; + } + } + // If we got here, we didn't match a closing backtick sequence. + this.pos = afterOpenTicks; + inlines.push({ t: 'Str', c: ticks }); + return true; +}; + +// Parse a backslash-escaped special character, adding either the escaped +// character, a hard line break (if the backslash is followed by a newline), +// or a literal backslash to the 'inlines' list. +var parseBackslash = function(inlines) { + var subj = this.subject, + pos = this.pos; + if (subj.charCodeAt(pos) === C_BACKSLASH) { + if (subj.charAt(pos + 1) === '\n') { + this.pos = this.pos + 2; + inlines.push({ t: 'Hardbreak' }); + } else if (reEscapable.test(subj.charAt(pos + 1))) { + this.pos = this.pos + 2; + inlines.push({ t: 'Str', c: subj.charAt(pos + 1) }); + } else { + this.pos++; + inlines.push({t: 'Str', c: '\\'}); + } + return true; + } else { + return false; + } +}; + +// Attempt to parse an autolink (URL or email in pointy brackets). +var parseAutolink = function(inlines) { + var m; + var dest; + if ((m = this.match(/^<([a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*)>/))) { // email autolink + dest = m.slice(1,-1); + inlines.push( + {t: 'Link', + label: [{ t: 'Str', c: dest }], + destination: 'mailto:' + encodeURI(unescape(dest)) }); + return true; + } else if ((m = this.match(/^<(?:coap|doi|javascript|aaa|aaas|about|acap|cap|cid|crid|data|dav|dict|dns|file|ftp|geo|go|gopher|h323|http|https|iax|icap|im|imap|info|ipp|iris|iris.beep|iris.xpc|iris.xpcs|iris.lwz|ldap|mailto|mid|msrp|msrps|mtqp|mupdate|news|nfs|ni|nih|nntp|opaquelocktoken|pop|pres|rtsp|service|session|shttp|sieve|sip|sips|sms|snmp|soap.beep|soap.beeps|tag|tel|telnet|tftp|thismessage|tn3270|tip|tv|urn|vemmi|ws|wss|xcon|xcon-userid|xmlrpc.beep|xmlrpc.beeps|xmpp|z39.50r|z39.50s|adiumxtra|afp|afs|aim|apt|attachment|aw|beshare|bitcoin|bolo|callto|chrome|chrome-extension|com-eventbrite-attendee|content|cvs|dlna-playsingle|dlna-playcontainer|dtn|dvb|ed2k|facetime|feed|finger|fish|gg|git|gizmoproject|gtalk|hcp|icon|ipn|irc|irc6|ircs|itms|jar|jms|keyparc|lastfm|ldaps|magnet|maps|market|message|mms|ms-help|msnim|mumble|mvn|notes|oid|palm|paparazzi|platform|proxy|psyc|query|res|resource|rmi|rsync|rtmp|secondlife|sftp|sgn|skype|smb|soldat|spotify|ssh|steam|svn|teamspeak|things|udp|unreal|ut2004|ventrilo|view-source|webcal|wtai|wyciwyg|xfire|xri|ymsgr):[^<>\x00-\x20]*>/i))) { + dest = m.slice(1,-1); + inlines.push({ + t: 'Link', + label: [{ t: 'Str', c: dest }], + destination: encodeURI(unescape(dest)) }); + return true; + } else { + return false; + } +}; + +// Attempt to parse a raw HTML tag. +var parseHtmlTag = function(inlines) { + var m = this.match(reHtmlTag); + if (m) { + inlines.push({ t: 'Html', c: m }); + return true; + } else { + return false; + } +}; + +// Scan a sequence of characters with code cc, and return information about +// the number of delimiters and whether they are positioned such that +// they can open and/or close emphasis or strong emphasis. A utility +// function for strong/emph parsing. +var scanDelims = function(cc) { + var numdelims = 0; + var first_close_delims = 0; + var char_before, char_after, cc_after; + var startpos = this.pos; + + char_before = this.pos === 0 ? '\n' : + this.subject.charAt(this.pos - 1); + + while (this.peek() === cc) { + numdelims++; + this.pos++; + } + + cc_after = this.peek(); + if (cc_after === -1) { + char_after = '\n'; + } else { + char_after = fromCodePoint(cc_after); + } + + var can_open = numdelims > 0 && numdelims <= 3 && !(/\s/.test(char_after)); + var can_close = numdelims > 0 && numdelims <= 3 && !(/\s/.test(char_before)); + if (cc === C_UNDERSCORE) { + can_open = can_open && !((/[a-z0-9]/i).test(char_before)); + can_close = can_close && !((/[a-z0-9]/i).test(char_after)); + } + this.pos = startpos; + return { numdelims: numdelims, + can_open: can_open, + can_close: can_close }; +}; + +var Emph = function(ils) { + return {t: 'Emph', c: ils}; +}; + +var Strong = function(ils) { + return {t: 'Strong', c: ils}; +}; + +var Str = function(s) { + return {t: 'Str', c: s}; +}; + +// Attempt to parse emphasis or strong emphasis. +var parseEmphasis = function(cc,inlines) { + var startpos = this.pos; + var c ; + var first_close = 0; + c = fromCodePoint(cc); + + var numdelims; + var numclosedelims; + var delimpos; + + // Get opening delimiters. + res = this.scanDelims(cc); + numdelims = res.numdelims; + + if (numdelims === 0) { + this.pos = startpos; + return false; + } + + if (numdelims >= 4 || !res.can_open) { + this.pos += numdelims; + inlines.push(Str(this.subject.slice(startpos, startpos + numdelims))); + return true; + } + + this.pos += numdelims; + + var delims_to_match = numdelims; + + var current = []; + var firstend; + var firstpos; + var state = 0; + var can_close = false; + var can_open = false; + var last_emphasis_closer = null; + while (this.last_emphasis_closer[c] >= this.pos) { + res = this.scanDelims(cc); + numclosedelims = res.numdelims; + + if (res.can_close) { + if (last_emphasis_closer === null || + last_emphasis_closer < this.pos) { + last_emphasis_closer = this.pos; + } + if (numclosedelims === 3 && delims_to_match === 3) { + delims_to_match -= 3; + this.pos += 3; + current = [{t: 'Strong', c: [{t: 'Emph', c: current}]}]; + } else if (numclosedelims >= 2 && delims_to_match >= 2) { + delims_to_match -= 2; + this.pos += 2; + firstend = current.length; + firstpos = this.pos; + current = [{t: 'Strong', c: current}]; + } else if (numclosedelims >= 1 && delims_to_match >= 1) { + delims_to_match -= 1; + this.pos += 1; + firstend = current.length; + firstpos = this.pos; + current = [{t: 'Emph', c: current}]; + } else { + if (!(this.parseInline(current,true))) { + break; + } + } + if (delims_to_match === 0) { + Array.prototype.push.apply(inlines, current); + return true; + } + } else if (!(this.parseInline(current,true))) { + break; + } + } + + // we didn't match emphasis: fallback + inlines.push(Str(this.subject.slice(startpos, + startpos + delims_to_match))); + if (delims_to_match < numdelims) { + Array.prototype.push.apply(inlines, current.slice(0,firstend)); + this.pos = firstpos; + } else { // delims_to_match === numdelims + this.pos = startpos + delims_to_match; + } + + if (last_emphasis_closer) { + this.last_emphasis_closer[c] = last_emphasis_closer; + } + return true; +}; + +// Attempt to parse link title (sans quotes), returning the string +// or null if no match. +var parseLinkTitle = function() { + var title = this.match(reLinkTitle); + if (title) { + // chop off quotes from title and unescape: + return unescapeEntBS(title.substr(1, title.length - 2)); + } else { + return null; + } +}; + +// Attempt to parse link destination, returning the string or +// null if no match. +var parseLinkDestination = function() { + var res = this.match(reLinkDestinationBraces); + if (res) { // chop off surrounding <..>: + return encodeURI(unescape(unescapeEntBS(res.substr(1, res.length - 2)))); + } else { + res = this.match(reLinkDestination); + if (res !== null) { + return encodeURI(unescape(unescapeEntBS(res))); + } else { + return null; + } + } +}; + +// Attempt to parse a link label, returning number of characters parsed. +var parseLinkLabel = function() { + if (this.peek() != C_OPEN_BRACKET) { + return 0; + } + var startpos = this.pos; + var nest_level = 0; + if (this.label_nest_level > 0) { + // If we've already checked to the end of this subject + // for a label, even with a different starting [, we + // know we won't find one here and we can just return. + // This avoids lots of backtracking. + // Note: nest level 1 would be: [foo [bar] + // nest level 2 would be: [foo [bar [baz] + this.label_nest_level--; + return 0; + } + this.pos++; // advance past [ + var c; + while ((c = this.peek()) && c != -1 && (c != C_CLOSE_BRACKET || nest_level > 0)) { + switch (c) { + case C_BACKTICK: + this.parseBackticks([]); + break; + case C_LESSTHAN: + if (!(this.parseAutolink([]) || this.parseHtmlTag([]))) { + this.pos++; + } + break; + case C_OPEN_BRACKET: // nested [] + nest_level++; + this.pos++; + break; + case C_CLOSE_BRACKET: // nested [] + nest_level--; + this.pos++; + break; + case C_BACKSLASH: + this.parseBackslash([]); + break; + default: + this.parseString([]); + } + } + if (c === C_CLOSE_BRACKET) { + this.label_nest_level = 0; + this.pos++; // advance past ] + return this.pos - startpos; + } else { + if (c === -1) { + this.label_nest_level = nest_level; + } + this.pos = startpos; + return 0; + } +}; + +// Parse raw link label, including surrounding [], and return +// inline contents. (Note: this is not a method of InlineParser.) +var parseRawLabel = function(s) { + // note: parse without a refmap; we don't want links to resolve + // in nested brackets! + return new InlineParser().parse(s.substr(1, s.length - 2), {}); +}; + +// Attempt to parse a link. If successful, return the link. +var parseLink = function(inlines) { + var startpos = this.pos; + var reflabel; + var n; + var dest; + var title; + + n = this.parseLinkLabel(); + if (n === 0) { + return false; + } + var afterlabel = this.pos; + var rawlabel = this.subject.substr(startpos, n); + + // if we got this far, we've parsed a label. + // Try to parse an explicit link: [label](url "title") + if (this.peek() == C_OPEN_PAREN) { + this.pos++; + if (this.spnl() && + ((dest = this.parseLinkDestination()) !== null) && + this.spnl() && + // make sure there's a space before the title: + (/^\s/.test(this.subject.charAt(this.pos - 1)) && + (title = this.parseLinkTitle() || '') || true) && + this.spnl() && + this.match(/^\)/)) { + inlines.push({ t: 'Link', + destination: dest, + title: title, + label: parseRawLabel(rawlabel) }); + return true; + } else { + this.pos = startpos; + return false; + } + } + // If we're here, it wasn't an explicit link. Try to parse a reference link. + // first, see if there's another label + var savepos = this.pos; + this.spnl(); + var beforelabel = this.pos; + n = this.parseLinkLabel(); + if (n == 2) { + // empty second label + reflabel = rawlabel; + } else if (n > 0) { + reflabel = this.subject.slice(beforelabel, beforelabel + n); + } else { + this.pos = savepos; + reflabel = rawlabel; + } + // lookup rawlabel in refmap + var link = this.refmap[normalizeReference(reflabel)]; + if (link) { + inlines.push({t: 'Link', + destination: link.destination, + title: link.title, + label: parseRawLabel(rawlabel) }); + return true; + } else { + this.pos = startpos; + return false; + } + // Nothing worked, rewind: + this.pos = startpos; + return false; +}; + +// Attempt to parse an entity, return Entity object if successful. +var parseEntity = function(inlines) { + var m; + if ((m = this.match(reEntityHere))) { + inlines.push({ t: 'Str', c: entityToChar(m) }); + return true; + } else { + return false; + } +}; + +// Parse a run of ordinary characters, or a single character with +// a special meaning in markdown, as a plain string, adding to inlines. +var parseString = function(inlines) { + var m; + if ((m = this.match(reMain))) { + inlines.push({ t: 'Str', c: m }); + return true; + } else { + return false; + } +}; + +// Parse a newline. If it was preceded by two spaces, return a hard +// line break; otherwise a soft line break. +var parseNewline = function(inlines) { + var m = this.match(/^ *\n/); + if (m) { + if (m.length > 2) { + inlines.push({ t: 'Hardbreak' }); + } else if (m.length > 0) { + inlines.push({ t: 'Softbreak' }); + } + return true; + } + return false; +}; + +// Attempt to parse an image. If the opening '!' is not followed +// by a link, return a literal '!'. +var parseImage = function(inlines) { + if (this.match(/^!/)) { + var link = this.parseLink(inlines); + if (link) { + inlines[inlines.length - 1].t = 'Image'; + return true; + } else { + inlines.push({ t: 'Str', c: '!' }); + return true; + } + } else { + return false; + } +}; + +// Attempt to parse a link reference, modifying refmap. +var parseReference = function(s, refmap) { + this.subject = s; + this.pos = 0; + this.label_nest_level = 0; + var rawlabel; + var dest; + var title; + var matchChars; + var startpos = this.pos; + var match; + + // label: + matchChars = this.parseLinkLabel(); + if (matchChars === 0) { + return 0; + } else { + rawlabel = this.subject.substr(0, matchChars); + } + + // colon: + if (this.peek() === C_COLON) { + this.pos++; + } else { + this.pos = startpos; + return 0; + } + + // link url + this.spnl(); + + dest = this.parseLinkDestination(); + if (dest === null || dest.length === 0) { + this.pos = startpos; + return 0; + } + + var beforetitle = this.pos; + this.spnl(); + title = this.parseLinkTitle(); + if (title === null) { + title = ''; + // rewind before spaces + this.pos = beforetitle; + } + + // make sure we're at line end: + if (this.match(/^ *(?:\n|$)/) === null) { + this.pos = startpos; + return 0; + } + + var normlabel = normalizeReference(rawlabel); + + if (!refmap[normlabel]) { + refmap[normlabel] = { destination: dest, title: title }; + } + return this.pos - startpos; +}; + +// Parse the next inline element in subject, advancing subject position. +// If memoize is set, memoize the result. +// On success, add the result to the inlines list, and return true. +// On failure, return false. +var parseInline = function(inlines, memoize) { + var startpos = this.pos; + var origlen = inlines.length; + var memoized = memoize && this.memo[startpos]; + if (memoized) { + this.pos = memoized.endpos; + Array.prototype.push.apply(inlines, memoized.inline); + return true; + } + + var c = this.peek(); + if (c === -1) { + return false; + } + var res; + switch(c) { + case C_NEWLINE: + case C_SPACE: + res = this.parseNewline(inlines); + break; + case C_BACKSLASH: + res = this.parseBackslash(inlines); + break; + case C_BACKTICK: + res = this.parseBackticks(inlines); + break; + case C_ASTERISK: + case C_UNDERSCORE: + res = this.parseEmphasis(c, inlines); + break; + case C_OPEN_BRACKET: + res = this.parseLink(inlines); + break; + case C_BANG: + res = this.parseImage(inlines); + break; + case C_LESSTHAN: + res = this.parseAutolink(inlines) || this.parseHtmlTag(inlines); + break; + case C_AMPERSAND: + res = this.parseEntity(inlines); + break; + default: + res = this.parseString(inlines); + break; + } + if (!res) { + this.pos += 1; + inlines.push({t: 'Str', c: fromCodePoint(c)}); + } + + if (memoize) { + this.memo[startpos] = { inline: inlines.slice(origlen), + endpos: this.pos }; + } + return true; +}; + +// Parse s as a list of inlines, using refmap to resolve references. +var parseInlines = function(s, refmap) { + this.subject = s; + this.pos = 0; + this.refmap = refmap || {}; + this.memo = {}; + this.last_emphasis_closer = { '*': s.length, '_': s.length }; + var inlines = []; + while (this.parseInline(inlines, false)) { + } + return inlines; +}; + +// The InlineParser object. +function InlineParser(){ + return { + subject: '', + label_nest_level: 0, // used by parseLinkLabel method + last_emphasis_closer: null, // used by parseEmphasis method + pos: 0, + refmap: {}, + memo: {}, + match: match, + peek: peek, + spnl: spnl, + parseBackticks: parseBackticks, + parseBackslash: parseBackslash, + parseAutolink: parseAutolink, + parseHtmlTag: parseHtmlTag, + scanDelims: scanDelims, + parseEmphasis: parseEmphasis, + parseLinkTitle: parseLinkTitle, + parseLinkDestination: parseLinkDestination, + parseLinkLabel: parseLinkLabel, + parseLink: parseLink, + parseEntity: parseEntity, + parseString: parseString, + parseNewline: parseNewline, + parseImage: parseImage, + parseReference: parseReference, + parseInline: parseInline, + parse: parseInlines + }; +} + +module.exports.unescapeEntBS = unescapeEntBS; +module.exports.InlineParser = InlineParser; |