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