code: function clean(values) {
    var index = -1;
    var length = values.length;
    var result = [];
    var prev = null;
    var value;
  
    while (++index < length) {
      value = values[index];
  
      if (prev && 'value' in value && value.type === prev.type) {
        prev.value += value.value;
      } else {
        result.push(value);
        prev = value;
      }
    }
  
    return result;
  }
docs: /* Clean nodes: merges text's.