44 lines
1.4 KiB
JavaScript
44 lines
1.4 KiB
JavaScript
|
import chain from "./chain.js";
|
||
|
|
import compose from "./compose.js";
|
||
|
|
import map from "./map.js";
|
||
|
|
/**
|
||
|
|
* Returns the right-to-left Kleisli composition of the provided functions,
|
||
|
|
* each of which must return a value of a type supported by [`chain`](#chain).
|
||
|
|
*
|
||
|
|
* `R.composeK(h, g, f)` is equivalent to `R.compose(R.chain(h), R.chain(g), f)`.
|
||
|
|
*
|
||
|
|
* @func
|
||
|
|
* @memberOf R
|
||
|
|
* @since v0.16.0
|
||
|
|
* @category Function
|
||
|
|
* @sig Chain m => ((y -> m z), (x -> m y), ..., (a -> m b)) -> (a -> m z)
|
||
|
|
* @param {...Function} ...functions The functions to compose
|
||
|
|
* @return {Function}
|
||
|
|
* @see R.pipeK
|
||
|
|
* @deprecated since v0.26.0
|
||
|
|
* @example
|
||
|
|
*
|
||
|
|
* // get :: String -> Object -> Maybe *
|
||
|
|
* const get = R.curry((propName, obj) => Maybe(obj[propName]))
|
||
|
|
*
|
||
|
|
* // getStateCode :: Maybe String -> Maybe String
|
||
|
|
* const getStateCode = R.composeK(
|
||
|
|
* R.compose(Maybe.of, R.toUpper),
|
||
|
|
* get('state'),
|
||
|
|
* get('address'),
|
||
|
|
* get('user'),
|
||
|
|
* );
|
||
|
|
* getStateCode({"user":{"address":{"state":"ny"}}}); //=> Maybe.Just("NY")
|
||
|
|
* getStateCode({}); //=> Maybe.Nothing()
|
||
|
|
* @symb R.composeK(f, g, h)(a) = R.chain(f, R.chain(g, h(a)))
|
||
|
|
*/
|
||
|
|
|
||
|
|
export default function composeK() {
|
||
|
|
if (arguments.length === 0) {
|
||
|
|
throw new Error('composeK requires at least one argument');
|
||
|
|
}
|
||
|
|
|
||
|
|
var init = Array.prototype.slice.call(arguments);
|
||
|
|
var last = init.pop();
|
||
|
|
return compose(compose.apply(this, map(chain, init)), last);
|
||
|
|
}
|