markdown-it/lib/rules_inline/footnote_inline.js

// Process inline footnotes (^[...])

'use strict';

var parseLinkLabel = require('../helpers/parse_link_label');


module.exports = function footnote_inline(state, silent) {
  var labelStart,
      labelEnd,
      footnoteId,
      oldLength,
      max = state.posMax,
      start = state.pos;

  if (start + 2 >= max) { return false; }
  if (state.src.charCodeAt(start) !== 0x5E/* ^ */) { return false; }
  if (state.src.charCodeAt(start + 1) !== 0x5B/* [ */) { return false; }
  if (state.level >= state.options.maxNesting) { return false; }

  labelStart = start + 2;
  labelEnd = parseLinkLabel(state, start + 1);

  // parser failed to find ']', so it's not a valid note
  if (labelEnd < 0) { return false; }

  // We found the end of the link, and know for a fact it's a valid link;
  // so all that's left to do is to call tokenizer.
  //
  if (!silent) {
    if (!state.env.footnotes) { state.env.footnotes = {}; }
    if (!state.env.footnotes.list) { state.env.footnotes.list = []; }
    footnoteId = state.env.footnotes.list.length;

    state.pos = labelStart;
    state.posMax = labelEnd;

    state.push({
      type: 'footnote_ref',
      id: footnoteId,
      level: state.level
    });
    state.linkLevel++;
    oldLength = state.tokens.length;
    state.parser.tokenize(state);
    state.env.footnotes.list[footnoteId] = { tokens: state.tokens.splice(oldLength) };
    state.linkLevel--;
  }

  state.pos = labelEnd + 1;
  state.posMax = max;
  return true;
};