Mult

Overview

Mult is an opposite idea to Mix. It is a set of tools to setup a flow of data from one channel to many channels, a way to distribute a copy of values to other channels.

import { iterate, put } from 'csp-coffee/operators';
import { go } from 'csp-coffee/go';
import { makeChannel } from 'csp-coffee/channel';
import { CreatableBufferType } from 'csp-coffee/buffer';
import { attachMulter, tap } from 'csp-coffee/mult';

const sourceCh = makeChannel(CreatableBufferType.UNBLOCKING);
const destCh1 = makeChannel(CreatableBufferType.UNBLOCKING, 1);
const destCh2 = makeChannel(CreatableBufferType.UNBLOCKING, 1);


function* mainGenerator () {
    attachMulter(sourceCh);
    tap(sourceCh, destCh1);
    tap(sourceCh, destCh2);
    yield put(sourceCh, 'test1');
    yield put(sourceCh, 'test2');
    yield iterate((value) => {
        console.log(value);
    }, destCh1, destCh2);
}

go(mainGenerator)
// 'test1'
// 'test1'
// 'test2'
// 'test2'

Filtering values based on a predicate

tap function can also accept a predicate function as a third parameter to filter values that will flow from source channel to destination channel.

import { iterate, put } from 'csp-coffee/operators';
import { go } from 'csp-coffee/go';
import { makeChannel } from 'csp-coffee/channel';
import { CreatableBufferType } from 'csp-coffee/buffer';
import { attachMulter, tap } from 'csp-coffee/mult';

const sourceCh = makeChannel(CreatableBufferType.UNBLOCKING);
const destCh1 = makeChannel(CreatableBufferType.UNBLOCKING, 1);
const destCh2 = makeChannel(CreatableBufferType.UNBLOCKING, 1);


function* mainGenerator () {
    attachMulter(sourceCh);
    tap(sourceCh, destCh1, (value: number) => value % 2 === 0);
    tap(sourceCh, destCh2, (value: number) => value % 2 !== 0);
    yield put(sourceCh, 1);
    yield put(sourceCh, 2);
    console.log(yield take(destCh1));
    console.log(yield take(destCh2));
}

go(mainGenerator)
// 2
// 1

API

attachMulter<T = any>(ch: Channel): void

Will simply attach a special multer object to the channel which will let us pass this channel to other functions from multer package.

tap<T = any>(sourceChannel: Channel, destinationChannel: Channel, filter?: (data: T) => boolean): void

Will add a destination channel to the multer which will cause source channel to distribute a copy of its values to the destination channel. Also accepts a filter function which we looked at above.

untap<T = any>(sourceChannel: Channel, destinationChannelId: string): void

Provides a way to remove a destination channel from the multer.