commonmark/lib/blocks.js

a strongly specified, highly compatible variant of Markdown

"use strict";

var Node = require('./node');
var unescapeString = require('./common').unescapeString;
var OPENTAG = require('./common').OPENTAG;
var CLOSETAG = require('./common').CLOSETAG;

var CODE_INDENT = 4;

var C_TAB = 9;
var C_NEWLINE = 10;
var C_GREATERTHAN = 62;
var C_LESSTHAN = 60;
var C_SPACE = 32;
var C_OPEN_BRACKET = 91;

var InlineParser = require('./inlines');

var reHtmlBlockOpen = [
   /./, // dummy for 0
   /^<(?:script|pre|style)(?:\s|>|$)/i,
   /^<!--/,
   /^<[?]/,
   /^<![A-Z]/,
   /^<!\[CDATA\[/,
   /^<[/]?(?:address|article|aside|base|basefont|blockquote|body|caption|center|col|colgroup|dd|details|dialog|dir|div|dl|dt|fieldset|figcaption|figure|footer|form|frame|frameset|h[123456]|head|header|hr|html|iframe|legend|li|link|main|menu|menuitem|nav|noframes|ol|optgroup|option|p|param|section|source|summary|table|tbody|td|tfoot|th|thead|title|tr|track|ul)(?:\s|[/]?[>]|$)/i,
    new RegExp('^(?:' + OPENTAG + '|' + CLOSETAG + ')\\s*$', 'i')
];

var reHtmlBlockClose = [
   /./, // dummy for 0
   /<\/(?:script|pre|style)>/i,
   /-->/,
   /\?>/,
   />/,
   /\]\]>/
];

var reThematicBreak = /^(?:(?:\*[ \t]*){3,}|(?:_[ \t]*){3,}|(?:-[ \t]*){3,})[ \t]*$/;

var reMaybeSpecial = /^[#`~*+_=<>0-9-]/;

var reNonSpace = /[^ \t\f\v\r\n]/;

var reBulletListMarker = /^[*+-]/;

var reOrderedListMarker = /^(\d{1,9})([.)])/;

var reATXHeadingMarker = /^#{1,6}(?:[ \t]+|$)/;

var reCodeFence = /^`{3,}(?!.*`)|^~{3,}/;

var reClosingCodeFence = /^(?:`{3,}|~{3,})(?= *$)/;

var reSetextHeadingLine = /^(?:=+|-+)[ \t]*$/;

var reLineEnding = /\r\n|\n|\r/;

// Returns true if string contains only space characters.
var isBlank = function(s) {
    return !(reNonSpace.test(s));
};

var isSpaceOrTab = function(c) {
    return c === C_SPACE || c === C_TAB;
};

var peek = function(ln, pos) {
    if (pos < ln.length) {
        return ln.charCodeAt(pos);
    } else {
        return -1;
    }
};

// DOC PARSER

// These are methods of a Parser object, defined below.

// Returns true if block ends with a blank line, descending if needed
// into lists and sublists.
var endsWithBlankLine = function(block) {
    while (block) {
        if (block._lastLineBlank) {
            return true;
        }
        var t = block.type;
        if (!block._lastLineChecked &&
            (t === 'list' || t === 'item')) {
            block._lastLineChecked = true;
            block = block._lastChild;
        } else {
            block._lastLineChecked = true;
            break;
        }
    }
    return false;
};

// 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() {
    if (this.partiallyConsumedTab) {
      this.offset += 1; // skip over tab
      // add space characters:
      var charsToTab = 4 - (this.column % 4);
      this.tip._string_content += (' '.repeat(charsToTab));
    }
    this.tip._string_content += this.currentLine.slice(this.offset) + '\n';
};

// 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, offset) {
    while (!this.blocks[this.tip.type].canContain(tag)) {
        this.finalize(this.tip, this.lineNumber - 1);
    }

    var column_number = offset + 1; // offset 0 = column 1
    var newBlock = new Node(tag, [[this.lineNumber, column_number], [0, 0]]);
    newBlock._string_content = '';
    this.tip.appendChild(newBlock);
    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(parser, container) {
    var rest = parser.currentLine.slice(parser.nextNonspace);
    var match;
    var nextc;
    var spacesStartCol;
    var spacesStartOffset;
    var data = { type: null,
                 tight: true,  // lists are tight by default
                 bulletChar: null,
                 start: null,
                 delimiter: null,
                 padding: null,
                 markerOffset: parser.indent };
    if (parser.indent >= 4) {
        return null;
    }
    if ((match = rest.match(reBulletListMarker))) {
        data.type = 'bullet';
        data.bulletChar = match[0][0];

    } else if ((match = rest.match(reOrderedListMarker)) &&
                (container.type !== 'paragraph' ||
                 match[1] === '1')) {
        data.type = 'ordered';
        data.start = parseInt(match[1]);
        data.delimiter = match[2];
    } else {
        return null;
    }
    // make sure we have spaces after
    nextc = peek(parser.currentLine, parser.nextNonspace + match[0].length);
    if (!(nextc === -1 || nextc === C_TAB || nextc === C_SPACE)) {
        return null;
    }

    // if it interrupts paragraph, make sure first line isn't blank
    if (container.type === 'paragraph' && !parser.currentLine.slice(parser.nextNonspace + match[0].length).match(reNonSpace)) {
        return null;
    }

    // we've got a match! advance offset and calculate padding
    parser.advanceNextNonspace(); // to start of marker
    parser.advanceOffset(match[0].length, true); // to end of marker
    spacesStartCol = parser.column;
    spacesStartOffset = parser.offset;
    do {
        parser.advanceOffset(1, true);
        nextc = peek(parser.currentLine, parser.offset);
    } while (parser.column - spacesStartCol < 5 &&
           isSpaceOrTab(nextc));
    var blank_item = peek(parser.currentLine, parser.offset) === -1;
    var spaces_after_marker = parser.column - spacesStartCol;
    if (spaces_after_marker >= 5 ||
        spaces_after_marker < 1 ||
        blank_item) {
        data.padding = match[0].length + 1;
        parser.column = spacesStartCol;
        parser.offset = spacesStartOffset;
        if (isSpaceOrTab(peek(parser.currentLine, parser.offset))) {
            parser.advanceOffset(1, true);
        }
    } else {
        data.padding = match[0].length + spaces_after_marker;
    }
    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.bulletChar === item_data.bulletChar);
};

// Finalize and close any unmatched blocks.
var closeUnmatchedBlocks = function() {
    if (!this.allClosed) {
        // finalize any blocks not matched
        while (this.oldtip !== this.lastMatchedContainer) {
            var parent = this.oldtip._parent;
            this.finalize(this.oldtip, this.lineNumber - 1);
            this.oldtip = parent;
        }
        this.allClosed = true;
    }
};

// 'finalize' is run when the block is closed.
// 'continue' is run to check whether the block is continuing
// at a certain line and offset (e.g. whether a block quote
// contains a `>`.  It returns 0 for matched, 1 for not matched,
// and 2 for "we've dealt with this line completely, go to next."
var blocks = {
    document: {
        continue: function() { return 0; },
        finalize: function() { return; },
        canContain: function(t) { return (t !== 'item'); },
        acceptsLines: false
    },
    list: {
        continue: function() { return 0; },
        finalize: function(parser, block) {
            var item = block._firstChild;
            while (item) {
                // check for non-final list item ending with blank line:
                if (endsWithBlankLine(item) && item._next) {
                    block._listData.tight = false;
                    break;
                }
                // recurse into children of list item, to see if there are
                // spaces between any of them:
                var subitem = item._firstChild;
                while (subitem) {
                    if (endsWithBlankLine(subitem) &&
                        (item._next || subitem._next)) {
                        block._listData.tight = false;
                        break;
                    }
                    subitem = subitem._next;
                }
                item = item._next;
            }
        },
        canContain: function(t) { return (t === 'item'); },
        acceptsLines: false
    },
    block_quote: {
        continue: function(parser) {
            var ln = parser.currentLine;
            if (!parser.indented &&
                peek(ln, parser.nextNonspace) === C_GREATERTHAN) {
                parser.advanceNextNonspace();
                parser.advanceOffset(1, false);
                if (isSpaceOrTab(peek(ln, parser.offset))) {
                    parser.advanceOffset(1, true);
                }
            } else {
                return 1;
            }
            return 0;
        },
        finalize: function() { return; },
        canContain: function(t) { return (t !== 'item'); },
        acceptsLines: false
    },
    item: {
        continue: function(parser, container) {
            if (parser.blank) {
                if (container._firstChild == null) {
                    // Blank line after empty list item
                    return 1;
                } else {
                    parser.advanceNextNonspace();
                }
            } else if (parser.indent >=
                       container._listData.markerOffset +
                       container._listData.padding) {
                parser.advanceOffset(container._listData.markerOffset +
                    container._listData.padding, true);
            } else {
                return 1;
            }
            return 0;
        },
        finalize: function() { return; },
        canContain: function(t) { return (t !== 'item'); },
        acceptsLines: false
    },
    heading: {
        continue: function() {
            // a heading can never container > 1 line, so fail to match:
            return 1;
        },
        finalize: function() { return; },
        canContain: function() { return false; },
        acceptsLines: false
    },
    thematic_break: {
        continue: function() {
            // a thematic break can never container > 1 line, so fail to match:
            return 1;
        },
        finalize: function() { return; },
        canContain: function() { return false; },
        acceptsLines: false
    },
    code_block: {
        continue: function(parser, container) {
            var ln = parser.currentLine;
            var indent = parser.indent;
            if (container._isFenced) { // fenced
                var match = (indent <= 3 &&
                    ln.charAt(parser.nextNonspace) === container._fenceChar &&
                    ln.slice(parser.nextNonspace).match(reClosingCodeFence));
                if (match && match[0].length >= container._fenceLength) {
                    // closing fence - we're at end of line, so we can return
                    parser.lastLineLength = match[0].length;
                    parser.finalize(container, parser.lineNumber);
                    return 2;
                } else {
                    // skip optional spaces of fence offset
                    var i = container._fenceOffset;
                    while (i > 0 && isSpaceOrTab(peek(ln, parser.offset))) {
                        parser.advanceOffset(1, true);
                        i--;
                    }
                }
            } else { // indented
                if (indent >= CODE_INDENT) {
                    parser.advanceOffset(CODE_INDENT, true);
                } else if (parser.blank) {
                    parser.advanceNextNonspace();
                } else {
                    return 1;
                }
            }
            return 0;
        },
        finalize: function(parser, block) {
            if (block._isFenced) { // fenced
                // first line becomes info string
                var content = block._string_content;
                var newlinePos = content.indexOf('\n');
                var firstLine = content.slice(0, newlinePos);
                var rest = content.slice(newlinePos + 1);
                block.info = unescapeString(firstLine.trim());
                block._literal = rest;
            } else { // indented
                block._literal = block._string_content.replace(/(\n *)+$/, '\n');
            }
            block._string_content = null; // allow GC
        },
        canContain: function() { return false; },
        acceptsLines: true
    },
    html_block: {
        continue: function(parser, container) {
            return ((parser.blank &&
                     (container._htmlBlockType === 6 ||
                      container._htmlBlockType === 7)) ? 1 : 0);
        },
        finalize: function(parser, block) {
            block._literal = block._string_content.replace(/(\n *)+$/, '');
            block._string_content = null; // allow GC
        },
        canContain: function() { return false; },
        acceptsLines: true
    },
    paragraph: {
        continue: function(parser) {
            return (parser.blank ? 1 : 0);
        },
        finalize: function(parser, block) {
            var pos;
            var hasReferenceDefs = false;

            // try parsing the beginning as link reference definitions:
            while (peek(block._string_content, 0) === C_OPEN_BRACKET &&
                   (pos =
                    parser.inlineParser.parseReference(block._string_content,
                                                       parser.refmap))) {
                block._string_content = block._string_content.slice(pos);
                hasReferenceDefs = true;
            }
            if (hasReferenceDefs && isBlank(block._string_content)) {
                block.unlink();
            }
        },
        canContain: function() { return false; },
        acceptsLines: true
    }
};

// block start functions.  Return values:
// 0 = no match
// 1 = matched container, keep going
// 2 = matched leaf, no more block starts
var blockStarts = [
    // block quote
    function(parser) {
        if (!parser.indented &&
            peek(parser.currentLine, parser.nextNonspace) === C_GREATERTHAN) {
            parser.advanceNextNonspace();
            parser.advanceOffset(1, false);
            // optional following space
            if (isSpaceOrTab(peek(parser.currentLine, parser.offset))) {
                parser.advanceOffset(1, true);
            }
            parser.closeUnmatchedBlocks();
            parser.addChild('block_quote', parser.nextNonspace);
            return 1;
        } else {
            return 0;
        }
    },

    // ATX heading
    function(parser) {
        var match;
        if (!parser.indented &&
            (match = parser.currentLine.slice(parser.nextNonspace).match(reATXHeadingMarker))) {
            parser.advanceNextNonspace();
            parser.advanceOffset(match[0].length, false);
            parser.closeUnmatchedBlocks();
            var container = parser.addChild('heading', parser.nextNonspace);
            container.level = match[0].trim().length; // number of #s
            // remove trailing ###s:
            container._string_content =
                parser.currentLine.slice(parser.offset).replace(/^[ \t]*#+[ \t]*$/, '').replace(/[ \t]+#+[ \t]*$/, '');
            parser.advanceOffset(parser.currentLine.length - parser.offset);
            return 2;
        } else {
            return 0;
        }
    },

    // Fenced code block
    function(parser) {
        var match;
        if (!parser.indented &&
            (match = parser.currentLine.slice(parser.nextNonspace).match(reCodeFence))) {
            var fenceLength = match[0].length;
            parser.closeUnmatchedBlocks();
            var container = parser.addChild('code_block', parser.nextNonspace);
            container._isFenced = true;
            container._fenceLength = fenceLength;
            container._fenceChar = match[0][0];
            container._fenceOffset = parser.indent;
            parser.advanceNextNonspace();
            parser.advanceOffset(fenceLength, false);
            return 2;
        } else {
            return 0;
        }
    },

    // HTML block
    function(parser, container) {
        if (!parser.indented &&
            peek(parser.currentLine, parser.nextNonspace) === C_LESSTHAN) {
            var s = parser.currentLine.slice(parser.nextNonspace);
            var blockType;

            for (blockType = 1; blockType <= 7; blockType++) {
                if (reHtmlBlockOpen[blockType].test(s) &&
                    (blockType < 7 ||
                     container.type !== 'paragraph')) {
                    parser.closeUnmatchedBlocks();
                    // We don't adjust parser.offset;
                    // spaces are part of the HTML block:
                    var b = parser.addChild('html_block',
                                            parser.offset);
                    b._htmlBlockType = blockType;
                    return 2;
                }
            }
        }

        return 0;

    },

    // Setext heading
    function(parser, container) {
        var match;
        if (!parser.indented &&
            container.type === 'paragraph' &&
                   ((match = parser.currentLine.slice(parser.nextNonspace).match(reSetextHeadingLine)))) {
            parser.closeUnmatchedBlocks();
            // resolve reference link definitiosn
            var pos;
            while (peek(container._string_content, 0) === C_OPEN_BRACKET &&
                   (pos =
                    parser.inlineParser.parseReference(
                        container._string_content, parser.refmap))) {
                container._string_content =
                    container._string_content.slice(pos);
            }
            if (container._string_content.length > 0) {
              var heading = new Node('heading', container.sourcepos);
              heading.level = match[0][0] === '=' ? 1 : 2;
              heading._string_content = container._string_content;
              container.insertAfter(heading);
              container.unlink();
              parser.tip = heading;
              parser.advanceOffset(parser.currentLine.length - parser.offset, false);
              return 2;
            } else {
              return 0;
            }
        } else {
            return 0;
        }
    },

    // thematic break
    function(parser) {
        if (!parser.indented &&
            reThematicBreak.test(parser.currentLine.slice(parser.nextNonspace))) {
            parser.closeUnmatchedBlocks();
            parser.addChild('thematic_break', parser.nextNonspace);
            parser.advanceOffset(parser.currentLine.length - parser.offset, false);
            return 2;
        } else {
            return 0;
        }
    },

    // list item
    function(parser, container) {
        var data;

        if ((!parser.indented || container.type === 'list')
                && (data = parseListMarker(parser, container))) {
            parser.closeUnmatchedBlocks();

            // add the list if needed
            if (parser.tip.type !== 'list' ||
                !(listsMatch(container._listData, data))) {
                container = parser.addChild('list', parser.nextNonspace);
                container._listData = data;
            }

            // add the list item
            container = parser.addChild('item', parser.nextNonspace);
            container._listData = data;
            return 1;
        } else {
            return 0;
        }
    },

    // indented code block
    function(parser) {
        if (parser.indented &&
            parser.tip.type !== 'paragraph' &&
            !parser.blank) {
            // indented code
            parser.advanceOffset(CODE_INDENT, true);
            parser.closeUnmatchedBlocks();
            parser.addChild('code_block', parser.offset);
            return 2;
        } else {
            return 0;
        }
     }

];

var advanceOffset = function(count, columns) {
    var currentLine = this.currentLine;
    var charsToTab, charsToAdvance;
    var c;
    while (count > 0 && (c = currentLine[this.offset])) {
        if (c === '\t') {
            charsToTab = 4 - (this.column % 4);
            if (columns) {
                this.partiallyConsumedTab = charsToTab > count;
                charsToAdvance = charsToTab > count ? count : charsToTab;
                this.column += charsToAdvance;
                this.offset += this.partiallyConsumedTab ? 0 : 1;
                count -= charsToAdvance;
            } else {
                this.partiallyConsumedTab = false;
                this.column += charsToTab;
                this.offset += 1;
                count -= 1;
            }
        } else {
            this.partiallyConsumedTab = false;
            this.offset += 1;
            this.column += 1; // assume ascii; block starts are ascii
            count -= 1;
        }
    }
};

var advanceNextNonspace = function() {
    this.offset = this.nextNonspace;
    this.column = this.nextNonspaceColumn;
    this.partiallyConsumedTab = false;
};

var findNextNonspace = function() {
    var currentLine = this.currentLine;
    var i = this.offset;
    var cols = this.column;
    var c;

    while ((c = currentLine.charAt(i)) !== '') {
        if (c === ' ') {
            i++;
            cols++;
        } else if (c === '\t') {
            i++;
            cols += (4 - (cols % 4));
        } else {
            break;
        }
    }
    this.blank = (c === '\n' || c === '\r' || c === '');
    this.nextNonspace = i;
    this.nextNonspaceColumn = cols;
    this.indent = this.nextNonspaceColumn - this.column;
    this.indented = this.indent >= CODE_INDENT;
};

// 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) {
    var all_matched = true;
    var t;

    var container = this.doc;
    this.oldtip = this.tip;
    this.offset = 0;
    this.column = 0;
    this.blank = false;
    this.partiallyConsumedTab = false;
    this.lineNumber += 1;

    // replace NUL characters for security
    if (ln.indexOf('\u0000') !== -1) {
        ln = ln.replace(/\0/g, '\uFFFD');
    }

    this.currentLine = 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.
    var lastChild;
    while ((lastChild = container._lastChild) && lastChild._open) {
        container = lastChild;

        this.findNextNonspace();

        switch (this.blocks[container.type].continue(this, container)) {
        case 0: // we've matched, keep going
            break;
        case 1: // we've failed to match a block
            all_matched = false;
            break;
        case 2: // we've hit end of line for fenced code close and can return
            return;
        default:
            throw 'continue returned illegal value, must be 0, 1, or 2';
        }
        if (!all_matched) {
            container = container._parent; // back up to last matching block
            break;
        }
    }

    this.allClosed = (container === this.oldtip);
    this.lastMatchedContainer = container;

    var matchedLeaf = container.type !== 'paragraph' &&
            blocks[container.type].acceptsLines;
    var starts = this.blockStarts;
    var startsLen = starts.length;
    // Unless last matched container is a code block, try new container starts,
    // adding children to the last matched container:
    while (!matchedLeaf) {

        this.findNextNonspace();

        // this is a little performance optimization:
        if (!this.indented &&
            !reMaybeSpecial.test(ln.slice(this.nextNonspace))) {
            this.advanceNextNonspace();
            break;
        }

        var i = 0;
        while (i < startsLen) {
            var res = starts[i](this, container);
            if (res === 1) {
                container = this.tip;
                break;
            } else if (res === 2) {
                container = this.tip;
                matchedLeaf = true;
                break;
            } else {
                i++;
            }
        }

        if (i === startsLen) { // nothing matched
            this.advanceNextNonspace();
            break;
        }
    }

    // What remains at the offset is a text line.  Add the text to the
    // appropriate container.

   // First check for a lazy paragraph continuation:
    if (!this.allClosed && !this.blank &&
        this.tip.type === 'paragraph') {
        // lazy paragraph continuation
        this.addLine();

    } else { // not a lazy continuation

        // finalize any blocks not matched
        this.closeUnmatchedBlocks();
        if (this.blank && container.lastChild) {
            container.lastChild._lastLineBlank = true;
        }

        t = container.type;

        // 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 _lastLineBlank
        // on an empty list item, or if we just closed a fenced block.
        var lastLineBlank = this.blank &&
            !(t === 'block_quote' ||
              (t === 'code_block' && container._isFenced) ||
              (t === 'item' &&
               !container._firstChild &&
               container.sourcepos[0][0] === this.lineNumber));

        // propagate lastLineBlank up through parents:
        var cont = container;
        while (cont) {
            cont._lastLineBlank = lastLineBlank;
            cont = cont._parent;
        }

        if (this.blocks[t].acceptsLines) {
            this.addLine();
            // if HtmlBlock, check for end condition
            if (t === 'html_block' &&
                container._htmlBlockType >= 1 &&
                container._htmlBlockType <= 5 &&
                reHtmlBlockClose[container._htmlBlockType].test(this.currentLine.slice(this.offset))) {
                this.lastLineLength = ln.length;
                this.finalize(container, this.lineNumber);
            }

        } else if (this.offset < ln.length && !this.blank) {
            // create paragraph container for line
            container = this.addChild('paragraph', this.offset);
            this.advanceNextNonspace();
            this.addLine();
        }
    }
    this.lastLineLength = ln.length;
};

// 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, lineNumber) {
    var above = block._parent;
    block._open = false;
    block.sourcepos[1] = [lineNumber, this.lastLineLength];

    this.blocks[block.type].finalize(this, block);

    this.tip = above;
};

// Walk through a block & children recursively, parsing string content
// into inline content where appropriate.
var processInlines = function(block) {
    var node, event, t;
    var walker = block.walker();
    this.inlineParser.refmap = this.refmap;
    this.inlineParser.options = this.options;
    while ((event = walker.next())) {
        node = event.node;
        t = node.type;
        if (!event.entering && (t === 'paragraph' || t === 'heading')) {
            this.inlineParser.parse(node);
        }
    }
};

var Document = function() {
    var doc = new Node('document', [[1, 1], [0, 0]]);
    return doc;
};

// The main parsing function.  Returns a parsed document AST.
var parse = function(input) {
    this.doc = new Document();
    this.tip = this.doc;
    this.refmap = {};
    this.lineNumber = 0;
    this.lastLineLength = 0;
    this.offset = 0;
    this.column = 0;
    this.lastMatchedContainer = this.doc;
    this.currentLine = "";
    if (this.options.time) { console.time("preparing input"); }
    var lines = input.split(reLineEnding);
    var len = lines.length;
    if (input.charCodeAt(input.length - 1) === C_NEWLINE) {
        // ignore last blank line created by final newline
        len -= 1;
    }
    if (this.options.time) { console.timeEnd("preparing input"); }
    if (this.options.time) { console.time("block parsing"); }
    for (var i = 0; i < len; i++) {
        this.incorporateLine(lines[i]);
    }
    while (this.tip) {
        this.finalize(this.tip, len);
    }
    if (this.options.time) { console.timeEnd("block parsing"); }
    if (this.options.time) { console.time("inline parsing"); }
    this.processInlines(this.doc);
    if (this.options.time) { console.timeEnd("inline parsing"); }
    return this.doc;
};


// The Parser object.
function Parser(options){
    return {
        doc: new Document(),
        blocks: blocks,
        blockStarts: blockStarts,
        tip: this.doc,
        oldtip: this.doc,
        currentLine: "",
        lineNumber: 0,
        offset: 0,
        column: 0,
        nextNonspace: 0,
        nextNonspaceColumn: 0,
        indent: 0,
        indented: false,
        blank: false,
        partiallyConsumedTab: false,
        allClosed: true,
        lastMatchedContainer: this.doc,
        refmap: {},
        lastLineLength: 0,
        inlineParser: new InlineParser(options),
        findNextNonspace: findNextNonspace,
        advanceOffset: advanceOffset,
        advanceNextNonspace: advanceNextNonspace,
        addLine: addLine,
        addChild: addChild,
        incorporateLine: incorporateLine,
        finalize: finalize,
        processInlines: processInlines,
        closeUnmatchedBlocks: closeUnmatchedBlocks,
        parse: parse,
        options: options || {}
    };
}

module.exports = Parser;