ramda-extension/lib/reduceSource.js

Helpful functions built on top of the mighty Ramda

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _ramda = require("ramda");

var _headArg = _interopRequireDefault(require("./headArg"));

/**
 * Extends the reduce functionality by adding the original accumulator value
 * as a third argument and the original list as a fourth argument to the
 * iterator function.
 *
 * @func
 * @category List
 *
 * @param {Function} fn The iterator function. Receives four arguments, the
 *        accumulator, the current element, the source accumulator and the
 *        source list.
 * @param {*} acc The initial accumulator value and value passed as the source
 *        accumulator value in the iterator function.
 * @param {Array} list The list to iterator over and value passed as the source
 *        list in the iterator function.
 * @return {*} The reduced result.
 *
 * @example
 *        R_.reduceSource((acc, v, sAcc) => v + acc + sAcc, 1, [1, 2, 3]); // 10
 *        R_.reduceSource(R.pipe(R.unapply(R.flatten), R.sum), 0, [1, 2]); // 9
 *
 * @sig ((a, b, a, [b]) -> a) -> a -> [b] -> a
 */
var reduceSource = (0, _ramda.converge)(_ramda.reduce, [(0, _ramda.converge)(_ramda.partialRight, [_headArg.default, // iteratorFn
(0, _ramda.unapply)(_ramda.tail) // [accumulator, list]
]), (0, _ramda.nthArg)(1), // accumulator
(0, _ramda.nthArg)(2) // list
]);
var _default = reduceSource;
exports.default = _default;