46 lines
1.4 KiB
JavaScript
46 lines
1.4 KiB
JavaScript
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import _concat from "./internal/_concat.js";
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import _curry3 from "./internal/_curry3.js";
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/**
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* Applies a function to the value at the given index of an array, returning a
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* new copy of the array with the element at the given index replaced with the
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* result of the function application.
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*
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* @func
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* @memberOf R
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* @since v0.14.0
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* @category List
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* @sig Number -> (a -> a) -> [a] -> [a]
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* @param {Number} idx The index.
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* @param {Function} fn The function to apply.
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* @param {Array|Arguments} list An array-like object whose value
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* at the supplied index will be replaced.
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* @return {Array} A copy of the supplied array-like object with
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* the element at index `idx` replaced with the value
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* returned by applying `fn` to the existing element.
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* @see R.update
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* @example
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*
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* R.adjust(1, R.toUpper, ['a', 'b', 'c', 'd']); //=> ['a', 'B', 'c', 'd']
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* R.adjust(-1, R.toUpper, ['a', 'b', 'c', 'd']); //=> ['a', 'b', 'c', 'D']
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* @symb R.adjust(-1, f, [a, b]) = [a, f(b)]
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* @symb R.adjust(0, f, [a, b]) = [f(a), b]
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*/
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var adjust =
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/*#__PURE__*/
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_curry3(function adjust(idx, fn, list) {
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if (idx >= list.length || idx < -list.length) {
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return list;
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}
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var start = idx < 0 ? list.length : 0;
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var _idx = start + idx;
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var _list = _concat(list);
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_list[_idx] = fn(list[_idx]);
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return _list;
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});
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export default adjust;
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