1  var baseToString = require('./_baseToString'),
 2      castSlice = require('./_castSlice'),
 3      charsStartIndex = require('./_charsStartIndex'),
 4      stringToArray = require('./_stringToArray'),
 5      toString = require('./toString');
 6  
 7  /** Used to match leading whitespace. */
 8  var reTrimStart = /^\s+/;
 9  
10  /**
11   * Removes leading whitespace or specified characters from `string`.
12   *
13   * @static
14   * @memberOf _
15   * @since 4.0.0
16   * @category String
17   * @param {string} [string=''] The string to trim.
18   * @param {string} [chars=whitespace] The characters to trim.
19   * @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`.
20   * @returns {string} Returns the trimmed string.
21   * @example
22   *
23   * _.trimStart('  abc  ');
24   * // => 'abc  '
25   *
26   * _.trimStart('-_-abc-_-', '_-');
27   * // => 'abc-_-'
28   */
29  function trimStart(string, chars, guard) {
30    string = toString(string);
31    if (string && (guard || chars === undefined)) {
32      return string.replace(reTrimStart, '');
33    }
34    if (!string || !(chars = baseToString(chars))) {
35      return string;
36    }
37    var strSymbols = stringToArray(string),
38        start = charsStartIndex(strSymbols, stringToArray(chars));
39  
40    return castSlice(strSymbols, start).join('');
41  }
42  
43  module.exports = trimStart;