function parse (str, options) {
  var tokens = [];
  var key = 0;
  var index = 0;
  var path = '';
  var defaultDelimiter = options && options.delimiter || '/';
  var res;

  while ((res = PATH_REGEXP.exec(str)) != null) {
    var m = res[0];
    var escaped = res[1];
    var offset = res.index;
    path += str.slice(index, offset);
    index = offset + m.length;

    // Ignore already escaped sequences.
    if (escaped) {
      path += escaped[1];
      continue
    }

    var next = str[index];
    var prefix = res[2];
    var name = res[3];
    var capture = res[4];
    var group = res[5];
    var modifier = res[6];
    var asterisk = res[7];

    // Push the current path onto the tokens.
    if (path) {
      tokens.push(path);
      path = '';
    }

    var partial = prefix != null && next != null && next !== prefix;
    var repeat = modifier === '+' || modifier === '*';
    var optional = modifier === '?' || modifier === '*';
    var delimiter = res[2] || defaultDelimiter;
    var pattern = capture || group;

    tokens.push({
      name: name || key++,
      prefix: prefix || '',
      delimiter: delimiter,
      optional: optional,
      repeat: repeat,
      partial: partial,
      asterisk: !!asterisk,
      pattern: pattern ? escapeGroup(pattern) : (asterisk ? '.*' : '[^' + escapeString(delimiter) + ']+?')
    });
  }

  // Match any characters still remaining.
  if (index < str.length) {
    path += str.substr(index);
  }

  // If the path exists, push it onto the end.
  if (path) {
    tokens.push(path);
  }

  return tokens
}
Parse a string for the raw tokens.

@param  {string}  str
@param  {Object=} options
@return {!Array}