test-action-debian-package/node_modules/ramda/es/cond.js
Dawid Dziurla 9308795b8b
update
2020-03-26 15:37:35 +01:00

53 lines
1.6 KiB
JavaScript

import _arity from "./internal/_arity.js";
import _curry1 from "./internal/_curry1.js";
import map from "./map.js";
import max from "./max.js";
import reduce from "./reduce.js";
/**
* Returns a function, `fn`, which encapsulates `if/else, if/else, ...` logic.
* `R.cond` takes a list of [predicate, transformer] pairs. All of the arguments
* to `fn` are applied to each of the predicates in turn until one returns a
* "truthy" value, at which point `fn` returns the result of applying its
* arguments to the corresponding transformer. If none of the predicates
* matches, `fn` returns undefined.
*
* @func
* @memberOf R
* @since v0.6.0
* @category Logic
* @sig [[(*... -> Boolean),(*... -> *)]] -> (*... -> *)
* @param {Array} pairs A list of [predicate, transformer]
* @return {Function}
* @see R.ifElse, R.unless, R.when
* @example
*
* const fn = R.cond([
* [R.equals(0), R.always('water freezes at 0°C')],
* [R.equals(100), R.always('water boils at 100°C')],
* [R.T, temp => 'nothing special happens at ' + temp + '°C']
* ]);
* fn(0); //=> 'water freezes at 0°C'
* fn(50); //=> 'nothing special happens at 50°C'
* fn(100); //=> 'water boils at 100°C'
*/
var cond =
/*#__PURE__*/
_curry1(function cond(pairs) {
var arity = reduce(max, 0, map(function (pair) {
return pair[0].length;
}, pairs));
return _arity(arity, function () {
var idx = 0;
while (idx < pairs.length) {
if (pairs[idx][0].apply(this, arguments)) {
return pairs[idx][1].apply(this, arguments);
}
idx += 1;
}
});
});
export default cond;