@mapbox/jsxtreme-markdown/vendor/remark-parse/lib/tokenize/code-fenced.js

Transform Markdown into JSX or React component modules

'use strict';

module.exports = fencedCode;

var lineFeed = '\n';
var tab = '\t';
var space = ' ';
var tilde = '~';
var graveAccent = '`';

var minFenceCount = 3;
var tabSize = 4;

function fencedCode(eat, value, silent) {
  var self = this;
  var gfm = self.options.gfm;
  var length = value.length + 1;
  var index = 0;
  var subvalue = '';
  var fenceCount;
  var marker;
  var character;
  var flag;
  var lang;
  var meta;
  var queue;
  var content;
  var exdentedContent;
  var closing;
  var exdentedClosing;
  var indent;
  var now;

  if (!gfm) {
    return;
  }

  // Eat initial spacing.
  while (index < length) {
    character = value.charAt(index);

    if (character !== space && character !== tab) {
      break;
    }

    subvalue += character;
    index++;
  }

  indent = index;

  // Eat the fence.
  character = value.charAt(index);

  if (character !== tilde && character !== graveAccent) {
    return;
  }

  index++;
  marker = character;
  fenceCount = 1;
  subvalue += character;

  while (index < length) {
    character = value.charAt(index);

    if (character !== marker) {
      break;
    }

    subvalue += character;
    fenceCount++;
    index++;
  }

  if (fenceCount < minFenceCount) {
    return;
  }

  // Eat spacing before flag.
  while (index < length) {
    character = value.charAt(index);

    if (character !== space && character !== tab) {
      break;
    }

    subvalue += character;
    index++;
  }

  // Eat flag.
  flag = '';
  queue = '';

  while (index < length) {
    character = value.charAt(index);

    if (
      character === lineFeed ||
      (marker === graveAccent && character === marker)
    ) {
      break;
    }

    if (character === space || character === tab) {
      queue += character;
    } else {
      flag += queue + character;
      queue = '';
    }

    index++;
  }

  character = value.charAt(index);

  if (character && character !== lineFeed) {
    return;
  }

  if (silent) {
    return true;
  }

  now = eat.now();
  now.column += subvalue.length;
  now.offset += subvalue.length;

  subvalue += flag;
  flag = self.decode.raw(self.unescape(flag), now);

  if (queue) {
    subvalue += queue;
  }

  queue = '';
  closing = '';
  exdentedClosing = '';
  content = '';
  exdentedContent = '';
  var skip = true;

  // Eat content.
  while (index < length) {
    character = value.charAt(index);
    content += closing;
    exdentedContent += exdentedClosing;
    closing = '';
    exdentedClosing = '';

    if (character !== lineFeed) {
      content += character;
      exdentedClosing += character;
      index++;
      continue;
    }

    // The first line feed is ignored. Others aren’t.
    if (skip) {
      subvalue += character;
      skip = false;
    } else {
      closing += character;
      exdentedClosing += character;
    }

    queue = '';
    index++;

    while (index < length) {
      character = value.charAt(index);

      if (character !== space) {
        break;
      }

      queue += character;
      index++;
    }

    closing += queue;
    exdentedClosing += queue.slice(indent);

    if (queue.length >= tabSize) {
      continue;
    }

    queue = '';

    while (index < length) {
      character = value.charAt(index);

      if (character !== marker) {
        break;
      }

      queue += character;
      index++;
    }

    closing += queue;
    exdentedClosing += queue;

    if (queue.length < fenceCount) {
      continue;
    }

    queue = '';

    while (index < length) {
      character = value.charAt(index);

      if (character !== space && character !== tab) {
        break;
      }

      closing += character;
      exdentedClosing += character;
      index++;
    }

    if (!character || character === lineFeed) {
      break;
    }
  }

  subvalue += content + closing;

  // Get lang and meta from the flag.
  index = -1;
  length = flag.length;

  while (++index < length) {
    character = flag.charAt(index);

    if (character === space || character === tab) {
      if (!lang) {
        lang = flag.slice(0, index);
      }
    } else if (lang) {
      meta = flag.slice(index);
      break;
    }
  }

  return eat(subvalue)({
    type: 'code',
    lang: lang || flag || null,
    meta: meta || null,
    value: exdentedContent,
  });
}