HORIZON PROJECT

var baseToString = require('./_baseToString'),

    castSlice = require('./_castSlice'),

    charsStartIndex = require('./_charsStartIndex'),

    stringToArray = require('./_stringToArray'),

    toString = require('./toString');

/** Used to match leading and trailing whitespace. */

var reTrimStart = /^\s+/;

/**

 * Removes leading whitespace or specified characters from `string`.

 *

 * @static

 * @memberOf _

 * @since 4.0.0

 * @category String

 * @param {string} [string=''] The string to trim.

 * @param {string} [chars=whitespace] The characters to trim.

 * @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`.

 * @returns {string} Returns the trimmed string.

 * @example

 *

 * _.trimStart('  abc  ');

 * // => 'abc  '

 *

 * _.trimStart('-_-abc-_-', '_-');

 * // => 'abc-_-'

 */

function trimStart(string, chars, guard) {

  string = toString(string);

  if (string && (guard || chars === undefined)) {

    return string.replace(reTrimStart, '');

  }

  if (!string || !(chars = baseToString(chars))) {

    return string;

  }

  var strSymbols = stringToArray(string),

      start = charsStartIndex(strSymbols, stringToArray(chars));

  return castSlice(strSymbols, start).join('');

}

module.exports = trimStart;