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indexBy.js
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indexBy.js
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import reduceBy from './reduceBy.js';
/**
* Given a function that generates a key, turns a list of objects into an
* object indexing the objects by the given key. Note that if multiple
* objects generate the same value for the indexing key only the last value
* will be included in the generated object.
*
* Acts as a transducer if a transformer is given in list position.
*
* @func
* @memberOf R
* @since v0.19.0
* @category List
* @typedefn Idx = String | Int | Symbol
* @sig Idx a => (b -> a) -> [b] -> {a: b}
* @param {Function} fn Function :: a -> Idx
* @param {Array} array The array of objects to index
* @return {Object} An object indexing each array element by the given property.
* @see R.groupBy
* @example
*
* const list = [{id: 'xyz', title: 'A'}, {id: 'abc', title: 'B'}];
* R.indexBy(R.prop('id'), list);
* //=> {abc: {id: 'abc', title: 'B'}, xyz: {id: 'xyz', title: 'A'}}
*/
var indexBy = reduceBy(function(acc, elem) { return elem; }, null);
export default indexBy;