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