[d24f17c] | 1 | import _arity from "./internal/_arity.js";
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| 2 | import _curry1 from "./internal/_curry1.js";
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| 3 | import map from "./map.js";
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| 4 | import max from "./max.js";
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| 5 | import reduce from "./reduce.js";
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| 6 | /**
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| 7 | * Returns a function, `fn`, which encapsulates `if/else, if/else, ...` logic.
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| 8 | * `R.cond` takes a list of [predicate, transformer] pairs. All of the arguments
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| 9 | * to `fn` are applied to each of the predicates in turn until one returns a
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| 10 | * "truthy" value, at which point `fn` returns the result of applying its
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| 11 | * arguments to the corresponding transformer. If none of the predicates
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| 12 | * matches, `fn` returns undefined.
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| 13 | *
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| 14 | * **Please note**: This is not a direct substitute for a `switch` statement.
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| 15 | * Remember that both elements of every pair passed to `cond` are *functions*,
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| 16 | * and `cond` returns a function.
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| 17 | *
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| 18 | * @func
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| 19 | * @memberOf R
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| 20 | * @since v0.6.0
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| 21 | * @category Logic
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| 22 | * @sig [[(*... -> Boolean),(*... -> *)]] -> (*... -> *)
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| 23 | * @param {Array} pairs A list of [predicate, transformer]
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| 24 | * @return {Function}
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| 25 | * @see R.ifElse, R.unless, R.when
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| 26 | * @example
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| 27 | *
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| 28 | * const fn = R.cond([
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| 29 | * [R.equals(0), R.always('water freezes at 0°C')],
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| 30 | * [R.equals(100), R.always('water boils at 100°C')],
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| 31 | * [R.T, temp => 'nothing special happens at ' + temp + '°C']
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| 32 | * ]);
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| 33 | * fn(0); //=> 'water freezes at 0°C'
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| 34 | * fn(50); //=> 'nothing special happens at 50°C'
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| 35 | * fn(100); //=> 'water boils at 100°C'
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| 36 | */
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| 37 |
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| 38 | var cond =
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| 39 | /*#__PURE__*/
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| 40 | _curry1(function cond(pairs) {
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| 41 | var arity = reduce(max, 0, map(function (pair) {
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| 42 | return pair[0].length;
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| 43 | }, pairs));
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| 44 | return _arity(arity, function () {
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| 45 | var idx = 0;
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| 46 |
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| 47 | while (idx < pairs.length) {
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| 48 | if (pairs[idx][0].apply(this, arguments)) {
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| 49 | return pairs[idx][1].apply(this, arguments);
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| 50 | }
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| 51 |
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| 52 | idx += 1;
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| 53 | }
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| 54 | });
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| 55 | });
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| 56 |
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| 57 | export default cond; |
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