invert.js•1.03 kB
var _curry1 = require('./internal/_curry1');
var _has = require('./internal/_has');
var keys = require('./keys');
/**
* Same as R.invertObj, however this accounts for objects with duplicate values
* by putting the values into an array.
*
* @func
* @memberOf R
* @since v0.9.0
* @category Object
* @sig {s: x} -> {x: [ s, ... ]}
* @param {Object} obj The object or array to invert
* @return {Object} out A new object with keys
* in an array.
* @example
*
* var raceResultsByFirstName = {
* first: 'alice',
* second: 'jake',
* third: 'alice',
* };
* R.invert(raceResultsByFirstName);
* //=> { 'alice': ['first', 'third'], 'jake':['second'] }
*/
module.exports = _curry1(function invert(obj) {
var props = keys(obj);
var len = props.length;
var idx = 0;
var out = {};
while (idx < len) {
var key = props[idx];
var val = obj[key];
var list = _has(val, out) ? out[val] : (out[val] = []);
list[list.length] = key;
idx += 1;
}
return out;
});