foop
Version:
interfaces that describe their intentions.
34 lines (32 loc) • 912 B
JavaScript
const curry = require('../../fp/curry')
/**
* Makes an ascending comparator function out of a function that returns a value
* that can be compared with `<` and `>`.
* @since 5.0.0-beta.7
* @memberOf loop
*
* @param {Function} fn A function of arity one that returns a value that can be compared
* @param {*} a The first item to be compared.
* @param {*} b The second item to be compared.
* @return {Number} `-1` if fn(a) < fn(b), `1` if fn(b) < fn(a), otherwise `0`
*
* @fork v0.23.0
* @category Function
* @sig Ord b => (a -> b) -> a -> a -> Number
* @func
*
* @see R.descend
*
* @example
*
* var byAge = R.ascend(R.prop('age'));
* var people = [
* // ...
* ];
* var peopleByYoungestFirst = R.sort(byAge, people);
*/
module.exports = curry(2, function compareAscending(fn, a, b) {
var aa = fn(a)
var bb = fn(b)
return aa < bb ? -1 : aa > bb ? 1 : 0
})