robertpenner

// https://vsavkin.com/functional-typescript-316f0e003dc6

class Employee {
  constructor(public name: string, public salary: number) {}
}

class Department {
  constructor(public employees: Employee[]) {}

  works(employee: Employee): boolean {

dypsilon

/**
 * This short program will encrypt the user password
 * and insert a new record into a mock database.
 */
const Reader = require('fantasy-readers');
const R = require('ramda');
const crypto = require('crypto');

// our mock database
const database = [

mrkgnao

{-# LANGUAGE RecordWildCards, Arrows #-}

import Numeric
import Data.Char

import Control.Monad
import Data.Monoid ((<>))
import Data.List (nub, sort, reverse)

data RepeatBounds = RB

mtesseract

The Problem

Defining records in Haskell causes accessor functions for the record's fields to be defined. There is no seperate namespace for these accessor functions.

The Goal

Be able to

• use records in Haskell, which share field names.
• use lenses for accessing these fields

alxhub

src/
  app/                   (application root component)
    index.ts             (most components use this pattern of an index.ts, style.css, and template.html)
    style.css
    template.html
  entry/                 (different entrypoints)
    dev/
      main.ts            (main file for JIT mode)
      module.ts
    prod/

justinwoo

// install @types/react-redux and other nonsense

import * as React from 'react'
import { connect } from 'react-redux'
import { YourActualAppState } from './wherever-it-is.ts'

export function mapStateToProps({
  whatever
}: YourActualAppState) {
  return {

justinwoo

Here are some of the examples of Reactive Programming libraries I've found in Purescript and what I've thought about them so far:

Purescript Behaviors: https://github.com/paf31/purescript-behaviors

I've never used a library with truly continuous Behaviors, so this was really neat to try out for me. Really nice to use and comes with utilities for working with browser events already, and gives you good Event modules for picking your sampling options as necessary.

I will probably use this library for all of my future uses.

Purescript Signal: https://github.com/bodil/purescript-signal

Avaq

//
// utils
//

const thrush = x => f => f(x);

const indexBy = k => xs => xs.reduce((index, x) => {
  if(index[x[k]] != null) index[x[k]].push(x);
  else index[x[k]] = [x];
  return index;

busypeoples

Phantom types in ReasonML

Introduction

"A phantom type is a parametrised type whose parameters do not all appear on the right-hand side of its definition..." Haskell Wiki, PhantomType

The following write-up is intended as an introduction into using phantom types in ReasonML.

Taking a look at the above definition from the Haskell wiki, it states that phantom types are parametrised types where not all parameters appear on the right-hand side. Let's try to see if we can implement a similar example as in said wiki.

hallettj

/*
 * Concept for emulating higher-kinded types using Flow. Instead of passing
 * a type that has not been applied to parameters, this pattern passes
 * a type-level function that will map a parameter type to the desired
 * higher-kinded type applied to the given parameter.
 *
 * @flow
 */

// a higher-kinded type is represented indirectly via a type-level function from