curry.js (1644B)
1 var createWrap = require('./_createWrap'); 2 3 /** Used to compose bitmasks for function metadata. */ 4 var WRAP_CURRY_FLAG = 8; 5 6 /** 7 * Creates a function that accepts arguments of `func` and either invokes 8 * `func` returning its result, if at least `arity` number of arguments have 9 * been provided, or returns a function that accepts the remaining `func` 10 * arguments, and so on. The arity of `func` may be specified if `func.length` 11 * is not sufficient. 12 * 13 * The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, 14 * may be used as a placeholder for provided arguments. 15 * 16 * **Note:** This method doesn't set the "length" property of curried functions. 17 * 18 * @static 19 * @memberOf _ 20 * @since 2.0.0 21 * @category Function 22 * @param {Function} func The function to curry. 23 * @param {number} [arity=func.length] The arity of `func`. 24 * @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`. 25 * @returns {Function} Returns the new curried function. 26 * @example 27 * 28 * var abc = function(a, b, c) { 29 * return [a, b, c]; 30 * }; 31 * 32 * var curried = _.curry(abc); 33 * 34 * curried(1)(2)(3); 35 * // => [1, 2, 3] 36 * 37 * curried(1, 2)(3); 38 * // => [1, 2, 3] 39 * 40 * curried(1, 2, 3); 41 * // => [1, 2, 3] 42 * 43 * // Curried with placeholders. 44 * curried(1)(_, 3)(2); 45 * // => [1, 2, 3] 46 */ 47 function curry(func, arity, guard) { 48 arity = guard ? undefined : arity; 49 var result = createWrap(func, WRAP_CURRY_FLAG, undefined, undefined, undefined, undefined, undefined, arity); 50 result.placeholder = curry.placeholder; 51 return result; 52 } 53 54 // Assign default placeholders. 55 curry.placeholder = {}; 56 57 module.exports = curry;