@beenotung/tslib/curry.js

utils library in Typescript

"use strict";
/**
 * Created by beenotung on 12/26/16.
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.id = void 0;
exports.curry = curry;
exports.autoCurry = autoCurry;
const lang_1 = require("./lang");
/* reference : http://stackoverflow.com/questions/27996544/how-to-correctly-curry-a-function-in-javascript */
function curry(f) {
    const arity = f.length;
    const res = arity === 0 ? f : partial(f, arity, []);
    return res;
}
exports.id = curry((x) => x);
/** internal func, use id() instead */
function autoCurry(f) {
    const res = typeof f === 'function' && f.length > 0 ? partial(f, f.length, []) : f;
    return res;
}
/**
 * if enough N param,
 *   then take LAST N param, apply to f
 *     -- also carry acc to f (as bottom of args stack), but should be ignored by f)
 *     -- the functions wrapped by f might use the stacked (extra) args
 *     if this args has extra params,
 *       then apply them to the result of f
 *   else take all param, wait for extra param
 * */
function partial(f, arity, acc) {
    const next = function partialNext() {
        const args = arguments;
        const m = args.length;
        if (m < arity) {
            return partial(f, arity - m, (0, lang_1.concatArgs)(acc, args, 0, m));
        }
        const result = autoCurry(f.apply(null, (0, lang_1.concatArgs)(acc, args, 0, arity)));
        if (arity < m) {
            return autoCurry(result.apply(null, (0, lang_1.copyArray)(args, arity, m - arity)));
        }
        return result;
    };
    return next;
}