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60 lines
1.2 KiB
60 lines
1.2 KiB
/*---------------------------------------------------------------
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| 小工具 |
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---------------------------------------------------------------*/
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/**
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* 函数柯里化
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*
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* @example
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*
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* var abc = function(a, b, c) {
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* return [a, b, c];
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* };
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*
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* var curried = curry(abc);
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*
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* curried(1)(2)(3);
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* // => [1, 2, 3]
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*
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*/
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export function curryN (fn, n = null) {
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const needLen = typeof n === 'number' ? n : fn.length;
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function warp (...arg) {
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let argLen = arg.length;
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if(needLen - argLen <= n){
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return fn(...arg);
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} else {
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return (...newArg) => warp(...arg, ...newArg);
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}
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}
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return warp;
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}
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export function curry (fn) {
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return curryN(fn);
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}
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/**
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* 合并多个函数为一个，函数参数仅限1个
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*
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* @type signature
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* (a->b) -> (b->c) -> (a->c)
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*/
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export function compose (...fns){
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const filterFns = fns.filter(item => typeof item == 'function');
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return x => filterFns.reduceRight((acc, fn) => fn(acc), x);
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}
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/**
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* 数组 map 柯里化
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*
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* @type signature
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* (a->b) -> [a] -> [b]
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*/
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export const map = curry((fn, arr) => arr.map(fn));
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export default curry;
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