chain.js•996 B
var _curry2 = require('./internal/_curry2');
var _dispatchable = require('./internal/_dispatchable');
var _makeFlat = require('./internal/_makeFlat');
var _xchain = require('./internal/_xchain');
var map = require('./map');
/**
* `chain` maps a function over a list and concatenates the results. `chain`
* is also known as `flatMap` in some libraries
*
* Dispatches to the `chain` method of the second argument, if present.
*
* @func
* @memberOf R
* @since v0.3.0
* @category List
* @sig (a -> [b]) -> [a] -> [b]
* @param {Function} fn
* @param {Array} list
* @return {Array}
* @example
*
* var duplicate = n => [n, n];
* R.chain(duplicate, [1, 2, 3]); //=> [1, 1, 2, 2, 3, 3]
*/
module.exports = _curry2(_dispatchable('chain', _xchain, function chain(fn, monad) {
if (typeof monad === 'function') {
return function() {
return monad.call(this, fn.apply(this, arguments)).apply(this, arguments);
};
}
return _makeFlat(false)(map(fn, monad));
}));