ademar

// Based on the article 'Combinators for logic programming' by Michael Spivey and Silvija Seres.

let rec inf_seq n =  seq { yield n; yield! inf_seq (n+1) }

let rec lzw f l1 l2 =
    LazyList.delayed ( fun () -> 
    match l1,l2 with
    |LazyList.Nil, _ -> l2
    |_, LazyList.Nil -> l1
    |LazyList.Cons(p1,tail1),LazyList.Cons(p2,tail2)

mattfield

Everything David Nolen Mentioned

When watching David Nolen's excellent Lambda Jam keynote on InfoQ, the references to interesting reading came a little too fast and furious for me to jot down, so I went through the slides and put this gist together.

• The Dream Machine: J.C.R. Licklider and the Revolution That Made Computing Personal - M. Mitchell Waldrop
• Purely Functional Data Structures - Chris Okasaki
• Ideal Hash Trees - Phil Bagwell
• RRB-Trees: Efficient Immutable Vectors - Phil Bagwell, Tiark Rompf

tnolet

#!/bin/bash
# Perform installation as root
# Install prereqs

yum -y install libcurl libcurl-devel rrdtool rrdtool-devel rrdtool-prel libgcrypt-devel gcc make gcc-c++

# Get Collectd, untar it, make it and install

wget http://collectd.org/files/collectd-5.4.0.tar.gz
tar zxvf collectd-5.4.0.tar.gz

frenchy64

(ns clojure.core.typed.test.unsound-record
  (:require [clojure.core.typed :as t]))

(t/ann-record Foo [a :- Number])
(defrecord Foo [a])

(t/ann unsound [(t/Map Any Any) -> Number])
(defn unsound [r]
  (let [r (assoc r :a nil)]
    (assert (instance? Foo r))

laszlopandy

Elm Style Guide

Purpose

The goal of the style guide is foremost to promote consistency and reuse of pattern from other languages in order to improve readability and make Elm easier for beginners. This includes moving Elm away from Haskell’s indentation style and even making some parts look closer to JavaScript. These decisions are intentional.

We would like Elm to look friendly and familiar to users of any language — especially JavaScript — so they can discover Elm’s powerful features without being overwhelmed. This does not intend to weaken or discourage any features of Elm, but instead to make them more accessible.

A secondary goal of the style guide is to encourage short diffs when changes are made. This makes changes more clear, and helps when multiple people are collaborating.

Whitespace

evancz

Union Types

If Elm community is going to begin referring to "union types" instead of "algebraic data types" we should think about how that will work in practice. What discussions will we have? Will we find ourselves in awkward spots trying to explain things?

The following question/answer pairs simulate things I'd expect to see in a world of "union types". The pairs are grouped by what background I expect the questions to come from so we know the subtext. I have also added some meta comments in italic to explain my phrasing.

One thing to consider is that a lot of learners will not have a person to ask, so the path to arriving at these answers needs to be easy if you are just searching online.

General Questions

paf31

This blog post series has moved here.

You might also be interested in the 2016 version.

oakes

Contents

• Why care about Rust?
• The Toolchain
• Creating a New Project
• Modules
• Crates
• Types
• References
• Mutability

14427

use std::rc::Rc;

trait HKT<U> {
    type C; // Current type
    type T; // Type with C swapped with U
}

macro_rules! derive_hkt {
    ($t:ident) => {
        impl<T, U> HKT<U> for $t<T> {

ohanhi

Learning FP the hard way: Experiences on the Elm language

by Ossi Hanhinen, @ohanhi

with the support of Futurice 💚.

Licensed under CC BY 4.0.

Editorial note