40 lines
1.1 KiB
JavaScript
40 lines
1.1 KiB
JavaScript
var toInteger = require('./toInteger');
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/** Error message constants. */
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var FUNC_ERROR_TEXT = 'Expected a function';
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/**
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* Creates a function that invokes `func`, with the `this` binding and arguments
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* of the created function, while it's called less than `n` times. Subsequent
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* calls to the created function return the result of the last `func` invocation.
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*
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* @static
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* @memberOf _
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* @since 3.0.0
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* @category Function
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* @param {number} n The number of calls at which `func` is no longer invoked.
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* @param {Function} func The function to restrict.
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* @returns {Function} Returns the new restricted function.
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* @example
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*
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* jQuery(element).on('click', _.before(5, addContactToList));
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* // => Allows adding up to 4 contacts to the list.
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*/
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function before(n, func) {
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var result;
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if (typeof func != 'function') {
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throw new TypeError(FUNC_ERROR_TEXT);
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}
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n = toInteger(n);
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return function() {
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if (--n > 0) {
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result = func.apply(this, arguments);
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}
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if (n <= 1) {
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func = undefined;
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}
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return result;
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};
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}
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module.exports = before;
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