[d24f17c] | 1 | import _curry3 from "./internal/_curry3.js";
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| 2 | import _dispatchable from "./internal/_dispatchable.js";
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| 3 | import _xscan from "./internal/_xscan.js";
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| 4 | /**
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| 5 | * Scan is similar to [`reduce`](#reduce), but returns a list of successively
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| 6 | * reduced values from the left.
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| 7 | *
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| 8 | * Acts as a transducer if a transformer is given in list position.
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| 9 | *
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| 10 | * @func
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| 11 | * @memberOf R
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| 12 | * @since v0.10.0
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| 13 | * @category List
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| 14 | * @sig ((a, b) -> a) -> a -> [b] -> [a]
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| 15 | * @param {Function} fn The iterator function. Receives two values, the accumulator and the
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| 16 | * current element from the array
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| 17 | * @param {*} acc The accumulator value.
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| 18 | * @param {Array} list The list to iterate over.
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| 19 | * @return {Array} A list of all intermediately reduced values.
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| 20 | * @see R.reduce, R.mapAccum
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| 21 | * @example
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| 22 | *
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| 23 | * const numbers = [1, 2, 3, 4];
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| 24 | * const factorials = R.scan(R.multiply, 1, numbers); //=> [1, 1, 2, 6, 24]
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| 25 | * @symb R.scan(f, a, [b, c]) = [a, f(a, b), f(f(a, b), c)]
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| 26 | */
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| 27 |
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| 28 | var scan =
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| 29 | /*#__PURE__*/
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| 30 | _curry3(
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| 31 | /*#__PURE__*/
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| 32 | _dispatchable([], _xscan, function scan(fn, acc, list) {
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| 33 | var idx = 0;
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| 34 | var len = list.length;
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| 35 | var result = [acc];
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| 36 |
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| 37 | while (idx < len) {
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| 38 | acc = fn(acc, list[idx]);
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| 39 | result[idx + 1] = acc;
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| 40 | idx += 1;
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| 41 | }
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| 42 |
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| 43 | return result;
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| 44 | }));
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| 45 |
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| 46 | export default scan; |
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