markdown-it/lib/rules_block/footnote.js

// Process footnote reference list

'use strict';


module.exports = function footnote(state, startLine, endLine, silent) {
  var oldBMark, oldTShift, oldParentType, pos, label,
      start = state.bMarks[startLine] + state.tShift[startLine],
      max = state.eMarks[startLine];

  // line should be at least 5 chars - "[^x]:"
  if (start + 4 > max) { return false; }

  if (state.src.charCodeAt(start) !== 0x5B/* [ */) { return false; }
  if (state.src.charCodeAt(start + 1) !== 0x5E/* ^ */) { return false; }
  if (state.level >= state.options.maxNesting) { return false; }

  for (pos = start + 2; pos < max; pos++) {
    if (state.src.charCodeAt(pos) === 0x20) { return false; }
    if (state.src.charCodeAt(pos) === 0x5D /* ] */) {
      break;
    }
  }

  if (pos === start + 2) { return false; } // no empty footnote labels
  if (pos + 1 >= max || state.src.charCodeAt(++pos) !== 0x3A /* : */) { return false; }
  if (silent) { return true; }
  pos++;

  if (!state.env.footnotes) { state.env.footnotes = {}; }
  if (!state.env.footnotes.refs) { state.env.footnotes.refs = Object.create(null); }
  label = state.src.slice(start + 2, pos - 2);
  state.env.footnotes.refs[label] = -1;

  state.tokens.push({
    type: 'footnote_reference_open',
    label: label,
    level: state.level++
  });

  oldBMark = state.bMarks[startLine];
  oldTShift = state.tShift[startLine];
  oldParentType = state.parentType;
  state.tShift[startLine] = state.skipSpaces(pos) - pos;
  state.bMarks[startLine] = pos;
  state.blkIndent += 4;
  state.parentType = 'footnote';

  if (state.tShift[startLine] < state.blkIndent) {
    state.tShift[startLine] += state.blkIndent;
    state.bMarks[startLine] -= state.blkIndent;
  }

  state.parser.tokenize(state, startLine, endLine, true);

  state.parentType = oldParentType;
  state.blkIndent -= 4;
  state.tShift[startLine] = oldTShift;
  state.bMarks[startLine] = oldBMark;

  state.tokens.push({
    type: 'footnote_reference_close',
    level: --state.level
  });

  return true;
};