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diff --git a/js/lib/blocks.js b/js/lib/blocks.js
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+var C_GREATERTHAN = 62;
+var C_SPACE = 32;
+var C_OPEN_BRACKET = 91;
+
+var InlineParser = require('./inlines');
+var unescapeString = new InlineParser().unescapeString;
+
+// Returns true if string contains only space characters.
+var isBlank = function(s) {
+ return /^\s*$/.test(s);
+};
+
+// Convert tabs to spaces on each line using a 4-space tab stop.
+var detabLine = function(text) {
+ if (text.indexOf('\t') == -1) {
+ return text;
+ } else {
+ var lastStop = 0;
+ return text.replace(/\t/g, function(match, offset) {
+ var result = ' '.slice((offset - lastStop) % 4);
+ lastStop = offset + 1;
+ return result;
+ });
+ }
+};
+
+// Attempt to match a regex in string s at offset offset.
+// Return index of match or null.
+var matchAt = function(re, s, offset) {
+ var res = s.slice(offset).match(re);
+ if (res) {
+ return offset + res.index;
+ } else {
+ return null;
+ }
+};
+
+var BLOCKTAGNAME = '(?:article|header|aside|hgroup|iframe|blockquote|hr|body|li|map|button|object|canvas|ol|caption|output|col|p|colgroup|pre|dd|progress|div|section|dl|table|td|dt|tbody|embed|textarea|fieldset|tfoot|figcaption|th|figure|thead|footer|footer|tr|form|ul|h1|h2|h3|h4|h5|h6|video|script|style)';
+var HTMLBLOCKOPEN = "<(?:" + BLOCKTAGNAME + "[\\s/>]" + "|" +
+ "/" + BLOCKTAGNAME + "[\\s>]" + "|" + "[?!])";
+var reHtmlBlockOpen = new RegExp('^' + HTMLBLOCKOPEN, 'i');
+
+var reHrule = /^(?:(?:\* *){3,}|(?:_ *){3,}|(?:- *){3,}) *$/;
+
+
+// DOC PARSER
+
+// These are methods of a DocParser object, defined below.
+
+var makeBlock = function(tag, start_line, start_column) {
+ return { t: tag,
+ open: true,
+ last_line_blank: false,
+ start_line: start_line,
+ start_column: start_column,
+ end_line: start_line,
+ children: [],
+ parent: null,
+ // string_content is formed by concatenating strings, in finalize:
+ string_content: "",
+ strings: [],
+ inline_content: []
+ };
+};
+
+// Returns true if parent block can contain child block.
+var canContain = function(parent_type, child_type) {
+ return ( parent_type == 'Document' ||
+ parent_type == 'BlockQuote' ||
+ parent_type == 'ListItem' ||
+ (parent_type == 'List' && child_type == 'ListItem') );
+};
+
+// Returns true if block type can accept lines of text.
+var acceptsLines = function(block_type) {
+ return ( block_type == 'Paragraph' ||
+ block_type == 'IndentedCode' ||
+ block_type == 'FencedCode' );
+};
+
+// Returns true if block ends with a blank line, descending if needed
+// into lists and sublists.
+var endsWithBlankLine = function(block) {
+ if (block.last_line_blank) {
+ return true;
+ }
+ if ((block.t == 'List' || block.t == 'ListItem') && block.children.length > 0) {
+ return endsWithBlankLine(block.children[block.children.length - 1]);
+ } else {
+ return false;
+ }
+};
+
+// Break out of all containing lists, resetting the tip of the
+// document to the parent of the highest list, and finalizing
+// all the lists. (This is used to implement the "two blank lines
+// break of of all lists" feature.)
+var breakOutOfLists = function(block, line_number) {
+ var b = block;
+ var last_list = null;
+ do {
+ if (b.t === 'List') {
+ last_list = b;
+ }
+ b = b.parent;
+ } while (b);
+
+ if (last_list) {
+ while (block != last_list) {
+ this.finalize(block, line_number);
+ block = block.parent;
+ }
+ this.finalize(last_list, line_number);
+ this.tip = last_list.parent;
+ }
+};
+
+// Add a line to the block at the tip. We assume the tip
+// can accept lines -- that check should be done before calling this.
+var addLine = function(ln, offset) {
+ var s = ln.slice(offset);
+ if (!(this.tip.open)) {
+ throw({ msg: "Attempted to add line (" + ln + ") to closed container." });
+ }
+ this.tip.strings.push(s);
+};
+
+// Add block of type tag as a child of the tip. If the tip can't
+// accept children, close and finalize it and try its parent,
+// and so on til we find a block that can accept children.
+var addChild = function(tag, line_number, offset) {
+ while (!canContain(this.tip.t, tag)) {
+ this.finalize(this.tip, line_number);
+ }
+
+ var column_number = offset + 1; // offset 0 = column 1
+ var newBlock = makeBlock(tag, line_number, column_number);
+ this.tip.children.push(newBlock);
+ newBlock.parent = this.tip;
+ this.tip = newBlock;
+ return newBlock;
+};
+
+// Parse a list marker and return data on the marker (type,
+// start, delimiter, bullet character, padding) or null.
+var parseListMarker = function(ln, offset) {
+ var rest = ln.slice(offset);
+ var match;
+ var spaces_after_marker;
+ var data = {};
+ if (rest.match(reHrule)) {
+ return null;
+ }
+ if ((match = rest.match(/^[*+-]( +|$)/))) {
+ spaces_after_marker = match[1].length;
+ data.type = 'Bullet';
+ data.bullet_char = match[0][0];
+
+ } else if ((match = rest.match(/^(\d+)([.)])( +|$)/))) {
+ spaces_after_marker = match[3].length;
+ data.type = 'Ordered';
+ data.start = parseInt(match[1]);
+ data.delimiter = match[2];
+ } else {
+ return null;
+ }
+ var blank_item = match[0].length === rest.length;
+ if (spaces_after_marker >= 5 ||
+ spaces_after_marker < 1 ||
+ blank_item) {
+ data.padding = match[0].length - spaces_after_marker + 1;
+ } else {
+ data.padding = match[0].length;
+ }
+ return data;
+};
+
+// Returns true if the two list items are of the same type,
+// with the same delimiter and bullet character. This is used
+// in agglomerating list items into lists.
+var listsMatch = function(list_data, item_data) {
+ return (list_data.type === item_data.type &&
+ list_data.delimiter === item_data.delimiter &&
+ list_data.bullet_char === item_data.bullet_char);
+};
+
+// Analyze a line of text and update the document appropriately.
+// We parse markdown text by calling this on each line of input,
+// then finalizing the document.
+var incorporateLine = function(ln, line_number) {
+
+ var all_matched = true;
+ var last_child;
+ var first_nonspace;
+ var offset = 0;
+ var match;
+ var data;
+ var blank;
+ var indent;
+ var last_matched_container;
+ var i;
+ var CODE_INDENT = 4;
+
+ var container = this.doc;
+ var oldtip = this.tip;
+
+ // Convert tabs to spaces:
+ ln = detabLine(ln);
+
+ // For each containing block, try to parse the associated line start.
+ // Bail out on failure: container will point to the last matching block.
+ // Set all_matched to false if not all containers match.
+ while (container.children.length > 0) {
+ last_child = container.children[container.children.length - 1];
+ if (!last_child.open) {
+ break;
+ }
+ container = last_child;
+
+ match = matchAt(/[^ ]/, ln, offset);
+ if (match === null) {
+ first_nonspace = ln.length;
+ blank = true;
+ } else {
+ first_nonspace = match;
+ blank = false;
+ }
+ indent = first_nonspace - offset;
+
+ switch (container.t) {
+ case 'BlockQuote':
+ if (indent <= 3 && ln.charCodeAt(first_nonspace) === C_GREATERTHAN) {
+ offset = first_nonspace + 1;
+ if (ln.charCodeAt(offset) === C_SPACE) {
+ offset++;
+ }
+ } else {
+ all_matched = false;
+ }
+ break;
+
+ case 'ListItem':
+ if (indent >= container.list_data.marker_offset +
+ container.list_data.padding) {
+ offset += container.list_data.marker_offset +
+ container.list_data.padding;
+ } else if (blank) {
+ offset = first_nonspace;
+ } else {
+ all_matched = false;
+ }
+ break;
+
+ case 'IndentedCode':
+ if (indent >= CODE_INDENT) {
+ offset += CODE_INDENT;
+ } else if (blank) {
+ offset = first_nonspace;
+ } else {
+ all_matched = false;
+ }
+ break;
+
+ case 'ATXHeader':
+ case 'SetextHeader':
+ case 'HorizontalRule':
+ // a header can never container > 1 line, so fail to match:
+ all_matched = false;
+ break;
+
+ case 'FencedCode':
+ // skip optional spaces of fence offset
+ i = container.fence_offset;
+ while (i > 0 && ln.charCodeAt(offset) === C_SPACE) {
+ offset++;
+ i--;
+ }
+ break;
+
+ case 'HtmlBlock':
+ if (blank) {
+ all_matched = false;
+ }
+ break;
+
+ case 'Paragraph':
+ if (blank) {
+ container.last_line_blank = true;
+ all_matched = false;
+ }
+ break;
+
+ default:
+ }
+
+ if (!all_matched) {
+ container = container.parent; // back up to last matching block
+ break;
+ }
+ }
+
+ last_matched_container = container;
+
+ // This function is used to finalize and close any unmatched
+ // blocks. We aren't ready to do this now, because we might
+ // have a lazy paragraph continuation, in which case we don't
+ // want to close unmatched blocks. So we store this closure for
+ // use later, when we have more information.
+ var closeUnmatchedBlocks = function(mythis) {
+ // finalize any blocks not matched
+ while (!already_done && oldtip != last_matched_container) {
+ mythis.finalize(oldtip, line_number);
+ oldtip = oldtip.parent;
+ }
+ var already_done = true;
+ };
+
+ // Check to see if we've hit 2nd blank line; if so break out of list:
+ if (blank && container.last_line_blank) {
+ this.breakOutOfLists(container, line_number);
+ }
+
+ // Unless last matched container is a code block, try new container starts,
+ // adding children to the last matched container:
+ while (container.t != 'FencedCode' &&
+ container.t != 'IndentedCode' &&
+ container.t != 'HtmlBlock' &&
+ // this is a little performance optimization:
+ matchAt(/^[ #`~*+_=<>0-9-]/,ln,offset) !== null) {
+
+ match = matchAt(/[^ ]/, ln, offset);
+ if (match === null) {
+ first_nonspace = ln.length;
+ blank = true;
+ } else {
+ first_nonspace = match;
+ blank = false;
+ }
+ indent = first_nonspace - offset;
+
+ if (indent >= CODE_INDENT) {
+ // indented code
+ if (this.tip.t != 'Paragraph' && !blank) {
+ offset += CODE_INDENT;
+ closeUnmatchedBlocks(this);
+ container = this.addChild('IndentedCode', line_number, offset);
+ } else { // indent > 4 in a lazy paragraph continuation
+ break;
+ }
+
+ } else if (ln.charCodeAt(first_nonspace) === C_GREATERTHAN) {
+ // blockquote
+ offset = first_nonspace + 1;
+ // optional following space
+ if (ln.charCodeAt(offset) === C_SPACE) {
+ offset++;
+ }
+ closeUnmatchedBlocks(this);
+ container = this.addChild('BlockQuote', line_number, offset);
+
+ } else if ((match = ln.slice(first_nonspace).match(/^#{1,6}(?: +|$)/))) {
+ // ATX header
+ offset = first_nonspace + match[0].length;
+ closeUnmatchedBlocks(this);
+ container = this.addChild('ATXHeader', line_number, first_nonspace);
+ container.level = match[0].trim().length; // number of #s
+ // remove trailing ###s:
+ container.strings =
+ [ln.slice(offset).replace(/(?:(\\#) *#*| *#+) *$/,'$1')];
+ break;
+
+ } else if ((match = ln.slice(first_nonspace).match(/^`{3,}(?!.*`)|^~{3,}(?!.*~)/))) {
+ // fenced code block
+ var fence_length = match[0].length;
+ closeUnmatchedBlocks(this);
+ container = this.addChild('FencedCode', line_number, first_nonspace);
+ container.fence_length = fence_length;
+ container.fence_char = match[0][0];
+ container.fence_offset = first_nonspace - offset;
+ offset = first_nonspace + fence_length;
+ break;
+
+ } else if (matchAt(reHtmlBlockOpen, ln, first_nonspace) !== null) {
+ // html block
+ closeUnmatchedBlocks(this);
+ container = this.addChild('HtmlBlock', line_number, first_nonspace);
+ // note, we don't adjust offset because the tag is part of the text
+ break;
+
+ } else if (container.t == 'Paragraph' &&
+ container.strings.length === 1 &&
+ ((match = ln.slice(first_nonspace).match(/^(?:=+|-+) *$/)))) {
+ // setext header line
+ closeUnmatchedBlocks(this);
+ container.t = 'SetextHeader'; // convert Paragraph to SetextHeader
+ container.level = match[0][0] === '=' ? 1 : 2;
+ offset = ln.length;
+
+ } else if (matchAt(reHrule, ln, first_nonspace) !== null) {
+ // hrule
+ closeUnmatchedBlocks(this);
+ container = this.addChild('HorizontalRule', line_number, first_nonspace);
+ offset = ln.length - 1;
+ break;
+
+ } else if ((data = parseListMarker(ln, first_nonspace))) {
+ // list item
+ closeUnmatchedBlocks(this);
+ data.marker_offset = indent;
+ offset = first_nonspace + data.padding;
+
+ // add the list if needed
+ if (container.t !== 'List' ||
+ !(listsMatch(container.list_data, data))) {
+ container = this.addChild('List', line_number, first_nonspace);
+ container.list_data = data;
+ }
+
+ // add the list item
+ container = this.addChild('ListItem', line_number, first_nonspace);
+ container.list_data = data;
+
+ } else {
+ break;
+
+ }
+
+ if (acceptsLines(container.t)) {
+ // if it's a line container, it can't contain other containers
+ break;
+ }
+ }
+
+ // What remains at the offset is a text line. Add the text to the
+ // appropriate container.
+
+ match = matchAt(/[^ ]/, ln, offset);
+ if (match === null) {
+ first_nonspace = ln.length;
+ blank = true;
+ } else {
+ first_nonspace = match;
+ blank = false;
+ }
+ indent = first_nonspace - offset;
+
+ // First check for a lazy paragraph continuation:
+ if (this.tip !== last_matched_container &&
+ !blank &&
+ this.tip.t == 'Paragraph' &&
+ this.tip.strings.length > 0) {
+ // lazy paragraph continuation
+
+ this.last_line_blank = false;
+ this.addLine(ln, offset);
+
+ } else { // not a lazy continuation
+
+ // finalize any blocks not matched
+ closeUnmatchedBlocks(this);
+
+ // Block quote lines are never blank as they start with >
+ // and we don't count blanks in fenced code for purposes of tight/loose
+ // lists or breaking out of lists. We also don't set last_line_blank
+ // on an empty list item.
+ container.last_line_blank = blank &&
+ !(container.t == 'BlockQuote' ||
+ container.t == 'FencedCode' ||
+ (container.t == 'ListItem' &&
+ container.children.length === 0 &&
+ container.start_line == line_number));
+
+ var cont = container;
+ while (cont.parent) {
+ cont.parent.last_line_blank = false;
+ cont = cont.parent;
+ }
+
+ switch (container.t) {
+ case 'IndentedCode':
+ case 'HtmlBlock':
+ this.addLine(ln, offset);
+ break;
+
+ case 'FencedCode':
+ // check for closing code fence:
+ match = (indent <= 3 &&
+ ln.charAt(first_nonspace) == container.fence_char &&
+ ln.slice(first_nonspace).match(/^(?:`{3,}|~{3,})(?= *$)/));
+ if (match && match[0].length >= container.fence_length) {
+ // don't add closing fence to container; instead, close it:
+ this.finalize(container, line_number);
+ } else {
+ this.addLine(ln, offset);
+ }
+ break;
+
+ case 'ATXHeader':
+ case 'SetextHeader':
+ case 'HorizontalRule':
+ // nothing to do; we already added the contents.
+ break;
+
+ default:
+ if (acceptsLines(container.t)) {
+ this.addLine(ln, first_nonspace);
+ } else if (blank) {
+ // do nothing
+ } else if (container.t != 'HorizontalRule' &&
+ container.t != 'SetextHeader') {
+ // create paragraph container for line
+ container = this.addChild('Paragraph', line_number, first_nonspace);
+ this.addLine(ln, first_nonspace);
+ } else {
+ console.log("Line " + line_number.toString() +
+ " with container type " + container.t +
+ " did not match any condition.");
+
+ }
+ }
+ }
+};
+
+// Finalize a block. Close it and do any necessary postprocessing,
+// e.g. creating string_content from strings, setting the 'tight'
+// or 'loose' status of a list, and parsing the beginnings
+// of paragraphs for reference definitions. Reset the tip to the
+// parent of the closed block.
+var finalize = function(block, line_number) {
+ var pos;
+ // don't do anything if the block is already closed
+ if (!block.open) {
+ return 0;
+ }
+ block.open = false;
+ if (line_number > block.start_line) {
+ block.end_line = line_number - 1;
+ } else {
+ block.end_line = line_number;
+ }
+
+ switch (block.t) {
+ case 'Paragraph':
+ block.string_content = block.strings.join('\n').replace(/^ */m,'');
+ // delete block.strings;
+
+ // try parsing the beginning as link reference definitions:
+ while (block.string_content.charCodeAt(0) === C_OPEN_BRACKET &&
+ (pos = this.inlineParser.parseReference(block.string_content,
+ this.refmap))) {
+ block.string_content = block.string_content.slice(pos);
+ if (isBlank(block.string_content)) {
+ block.t = 'ReferenceDef';
+ break;
+ }
+ }
+ break;
+
+ case 'ATXHeader':
+ case 'SetextHeader':
+ case 'HtmlBlock':
+ block.string_content = block.strings.join('\n');
+ break;
+
+ case 'IndentedCode':
+ block.string_content = block.strings.join('\n').replace(/(\n *)*$/,'\n');
+ break;
+
+ case 'FencedCode':
+ // first line becomes info string
+ block.info = unescapeString(block.strings[0].trim());
+ if (block.strings.length == 1) {
+ block.string_content = '';
+ } else {
+ block.string_content = block.strings.slice(1).join('\n') + '\n';
+ }
+ break;
+
+ case 'List':
+ block.tight = true; // tight by default
+
+ var numitems = block.children.length;
+ var i = 0;
+ while (i < numitems) {
+ var item = block.children[i];
+ // check for non-final list item ending with blank line:
+ var last_item = i == numitems - 1;
+ if (endsWithBlankLine(item) && !last_item) {
+ block.tight = false;
+ break;
+ }
+ // recurse into children of list item, to see if there are
+ // spaces between any of them:
+ var numsubitems = item.children.length;
+ var j = 0;
+ while (j < numsubitems) {
+ var subitem = item.children[j];
+ var last_subitem = j == numsubitems - 1;
+ if (endsWithBlankLine(subitem) && !(last_item && last_subitem)) {
+ block.tight = false;
+ break;
+ }
+ j++;
+ }
+ i++;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ this.tip = block.parent || this.top;
+};
+
+// Walk through a block & children recursively, parsing string content
+// into inline content where appropriate. Returns new object.
+var processInlines = function(block) {
+ var newblock = {};
+ newblock.t = block.t;
+ newblock.start_line = block.start_line;
+ newblock.start_column = block.start_column;
+ newblock.end_line = block.end_line;
+
+ switch(block.t) {
+ case 'Paragraph':
+ newblock.inline_content =
+ this.inlineParser.parse(block.string_content.trim(), this.refmap);
+ break;
+ case 'SetextHeader':
+ case 'ATXHeader':
+ newblock.inline_content =
+ this.inlineParser.parse(block.string_content.trim(), this.refmap);
+ newblock.level = block.level;
+ break;
+ case 'List':
+ newblock.list_data = block.list_data;
+ newblock.tight = block.tight;
+ break;
+ case 'FencedCode':
+ newblock.string_content = block.string_content;
+ newblock.info = block.info;
+ break;
+ case 'IndentedCode':
+ case 'HtmlBlock':
+ newblock.string_content = block.string_content;
+ break;
+ default:
+ break;
+ }
+
+ if (block.children) {
+ var newchildren = [];
+ for (var i = 0; i < block.children.length; i++) {
+ newchildren.push(this.processInlines(block.children[i]));
+ }
+ newblock.children = newchildren;
+ }
+ return newblock;
+};
+
+// The main parsing function. Returns a parsed document AST.
+var parse = function(input) {
+ this.doc = makeBlock('Document', 1, 1);
+ this.tip = this.doc;
+ this.refmap = {};
+ var lines = input.replace(/\n$/,'').split(/\r\n|\n|\r/);
+ var len = lines.length;
+ for (var i = 0; i < len; i++) {
+ this.incorporateLine(lines[i], i+1);
+ }
+ while (this.tip) {
+ this.finalize(this.tip, len - 1);
+ }
+ return this.processInlines(this.doc);
+};
+
+
+// The DocParser object.
+function DocParser(){
+ return {
+ doc: makeBlock('Document', 1, 1),
+ tip: this.doc,
+ refmap: {},
+ inlineParser: new InlineParser(),
+ breakOutOfLists: breakOutOfLists,
+ addLine: addLine,
+ addChild: addChild,
+ incorporateLine: incorporateLine,
+ finalize: finalize,
+ processInlines: processInlines,
+ parse: parse
+ };
+}
+
+module.exports = DocParser;