forked from zhurui/management
44 lines
1.2 KiB
JavaScript
44 lines
1.2 KiB
JavaScript
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var baseToString = require('./_baseToString'),
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castSlice = require('./_castSlice'),
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charsStartIndex = require('./_charsStartIndex'),
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stringToArray = require('./_stringToArray'),
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toString = require('./toString');
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/** Used to match leading and trailing whitespace. */
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var reTrimStart = /^\s+/;
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/**
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* Removes leading whitespace or specified characters from `string`.
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*
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* @static
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* @memberOf _
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* @since 4.0.0
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* @category String
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* @param {string} [string=''] The string to trim.
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* @param {string} [chars=whitespace] The characters to trim.
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* @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`.
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* @returns {string} Returns the trimmed string.
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* @example
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*
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* _.trimStart(' abc ');
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* // => 'abc '
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*
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* _.trimStart('-_-abc-_-', '_-');
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* // => 'abc-_-'
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*/
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function trimStart(string, chars, guard) {
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string = toString(string);
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if (string && (guard || chars === undefined)) {
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return string.replace(reTrimStart, '');
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}
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if (!string || !(chars = baseToString(chars))) {
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return string;
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}
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var strSymbols = stringToArray(string),
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start = charsStartIndex(strSymbols, stringToArray(chars));
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return castSlice(strSymbols, start).join('');
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}
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module.exports = trimStart;
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