| // Observable is an Union Type, with the following variants | |
| const Empty = () => ['EMPTY'] | |
| const Cons = (head, tail) => ['CONS', head, tail] | |
| const Future = promise => ['FUTURE', promise] | |
| // race between 2 promises; each promise will resolve to a lazy value | |
| const lazyRace = (p1, p2) => Promise.race([p1,p2]).then(lazy => lazy()) | |
| // function composition | |
| const compose = (...fns) => (arg) => fns.reduceRight((res, f) => f(res), arg) |
| function*example() { | |
| const x = 10 | |
| const y = yield callcc(function*(k) { | |
| // ... | |
| yield k(20) | |
| throw "Unreachable code" | |
| }) | |
| console.log(x + y) | |
| } |
| {-# Language TypeSynonymInstances, FlexibleInstances #-} | |
| module Algj where | |
| import Debug.Trace | |
| import Data.Maybe | |
| import qualified Data.Map as M | |
| import qualified Data.Set as S | |
| import Control.Monad.Trans.State |
| {-# Language TypeSynonymInstances, FlexibleInstances #-} | |
| module Algw where | |
| import Data.Maybe | |
| import qualified Data.Map as M | |
| import qualified Data.Set as S | |
| import Control.Monad.Trans.State |
In Redux, reducer composition with combineReducers offers a powerful way to handle
complex update logic of an application. A reducer can encapsulate all the ways a part
of the state is mutated because it can react to multiple types of actions.
But in some cases there is also a need for another type of factoring: often the update logic is simple (for example setting a single value), and the there are many places in the state shape where the update logic is the same.
| // Getter a :: () -> a | |
| // gmap :: ((a -> b), Getter a), Getter b | |
| function gmap(fn, getter) { | |
| return () => fn(getter()) | |
| } | |
| // gcombine2 :: ((a,b) -> c, Getter a, Getter ab) -> Getter c | |
| function gcombine2(fn, getter1, getter2) { |
| function eachKey(obj, f) { | |
| for(var key in obj) { | |
| if( obj.hasOwnProperty(key) ) | |
| f(key, obj[key]); | |
| } | |
| } | |
| function adtcase (base, proto, key) { | |
| return (...args) => { | |
| var inst = new base(); |
| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <title>Redux rocket launcher example</title> | |
| <script src="https://npmcdn.com/redux@latest/dist/redux.min.js"></script> | |
| <script src="https://npmcdn.com/redux-saga@0.9.1/dist/redux-saga.js"></script> | |
| </head> | |
| <body> | |
| <p> | |
| Example created to compare Redux + redux-saga implementation with |
| import React from 'react'; | |
| import reclass from './reclass'; | |
| import Greeter from './Greeter'; | |
| function App(ctx) { | |
| ctx.state = { civility: 'Mr.' }; | |
| function changeCivility(e) { | |
| ctx.setState({ civility: e.target.value }); | |
| } |
| // concatAll : Stream (Stream a) -> Stream a | |
| Stream.prototype.concatAll = function() { | |
| return this.flatten( (s1, s2) => s1.concat(s2) ); | |
| } |