source: node_modules/ramda/src/reduce.js

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[d24f17c]1var _curry3 =
2/*#__PURE__*/
3require("./internal/_curry3.js");
4
5var _xReduce =
6/*#__PURE__*/
7require("./internal/_xReduce.js");
8
9var _xwrap =
10/*#__PURE__*/
11require("./internal/_xwrap.js");
12/**
13 * Returns a single item by iterating through the list, successively calling
14 * the iterator function and passing it an accumulator value and the current
15 * value from the array, and then passing the result to the next call.
16 *
17 * The iterator function receives two values: *(acc, value)*. It may use
18 * [`R.reduced`](#reduced) to shortcut the iteration.
19 *
20 * The arguments' order of [`reduceRight`](#reduceRight)'s iterator function
21 * is *(value, acc)*.
22 *
23 * Note: `R.reduce` does not skip deleted or unassigned indices (sparse
24 * arrays), unlike the native `Array.prototype.reduce` method. For more details
25 * on this behavior, see:
26 * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce#Description
27 *
28 * Be cautious of mutating and returning the accumulator. If you reuse it across
29 * invocations, it will continue to accumulate onto the same value. The general
30 * recommendation is to always return a new value. If you can't do so for
31 * performance reasons, then be sure to reinitialize the accumulator on each
32 * invocation.
33 *
34 * Dispatches to the `reduce` method of the third argument, if present. When
35 * doing so, it is up to the user to handle the [`R.reduced`](#reduced)
36 * shortcuting, as this is not implemented by `reduce`.
37 *
38 * @func
39 * @memberOf R
40 * @since v0.1.0
41 * @category List
42 * @sig ((a, b) -> a) -> a -> [b] -> a
43 * @param {Function} fn The iterator function. Receives two values, the accumulator and the
44 * current element from the array.
45 * @param {*} acc The accumulator value.
46 * @param {Array} list The list to iterate over.
47 * @return {*} The final, accumulated value.
48 * @see R.reduced, R.addIndex, R.reduceRight
49 * @example
50 *
51 * R.reduce(R.subtract, 0, [1, 2, 3, 4]) // => ((((0 - 1) - 2) - 3) - 4) = -10
52 * // - -10
53 * // / \ / \
54 * // - 4 -6 4
55 * // / \ / \
56 * // - 3 ==> -3 3
57 * // / \ / \
58 * // - 2 -1 2
59 * // / \ / \
60 * // 0 1 0 1
61 *
62 * @symb R.reduce(f, a, [b, c, d]) = f(f(f(a, b), c), d)
63 */
64
65
66var reduce =
67/*#__PURE__*/
68_curry3(function (xf, acc, list) {
69 return _xReduce(typeof xf === 'function' ? _xwrap(xf) : xf, acc, list);
70});
71
72module.exports = reduce;
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