test-action-debian-package/node_modules/ramda/es/composeP.js

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2020-03-26 14:37:35 +00:00
import pipeP from "./pipeP.js";
import reverse from "./reverse.js";
/**
* Performs right-to-left composition of one or more Promise-returning
* functions. The last arguments may have any arity; the remaining
* arguments must be unary.
*
* @func
* @memberOf R
* @since v0.10.0
* @category Function
* @sig ((y -> Promise z), (x -> Promise y), ..., (a -> Promise b)) -> (a -> Promise z)
* @param {...Function} functions The functions to compose
* @return {Function}
* @see R.pipeP
* @deprecated since v0.26.0
* @example
*
* const db = {
* users: {
* JOE: {
* name: 'Joe',
* followers: ['STEVE', 'SUZY']
* }
* }
* }
*
* // We'll pretend to do a db lookup which returns a promise
* const lookupUser = (userId) => Promise.resolve(db.users[userId])
* const lookupFollowers = (user) => Promise.resolve(user.followers)
* lookupUser('JOE').then(lookupFollowers)
*
* // followersForUser :: String -> Promise [UserId]
* const followersForUser = R.composeP(lookupFollowers, lookupUser);
* followersForUser('JOE').then(followers => console.log('Followers:', followers))
* // Followers: ["STEVE","SUZY"]
*/
export default function composeP() {
if (arguments.length === 0) {
throw new Error('composeP requires at least one argument');
}
return pipeP.apply(this, reverse(arguments));
}