paf31

This blog post series has moved here.

You might also be interested in the 2016 version.

andrevdm

open System
open System.IO
open System.Text
open System.Globalization
open System.Text.RegularExpressions

let l1 = 1.0
let l2 = 2.0
let ttlTrue = 2.3

andrewseidl

• update system

    sudo yum update

• install xmonad, xmonad-contrib, xmobar

    sudo yum install xmonad ghc-xmonad-contrib{,-devel} xmobar

• install cabal-install, for yeganesh

gatlin

What the fuck is a monad?

Or: functor? I 'ardly know 'er!

Monads are difficult to explain without sounding either patronizing or condescending: I would sound patronizing if I came up with some facile analogy and I would be condescending to describe it categorically.

Instead, I'll frame a problem and piece-by-piece solve the problem with what will turn out to be a monad.

jbgi

import static java.lang.System.*;

import java.util.function.BiFunction;
import java.util.function.Function;

// Implementation of a pseudo-GADT in Java, translating the examples from
// http://www.cs.ox.ac.uk/ralf.hinze/publications/With.pdf
// The technique presented below is, in fact, just an encoding of a normal Algebraic Data Type
// using a variation of the visitor pattern + the application of the Yoneda lemma to make it
// isomorphic to the targeted 'GADT'.

mathieuancelin

package bar.foo.lenses;

import java.util.function.BiFunction;
import java.util.function.Function;

public class Lens<A, B> {

    private final Function<A, B> getter;
    private final BiFunction<A, B, A> setter;

CMCDragonkai

Free Monad + Interpreter Pattern

It's like creating the front end and back end of a compiler inside Haskell without the need of Template Haskell!

Write your DSL AST as a Free Monad, and then interpret the monad any way you like.

The advantage is that you get to swap out your interpreter, and your main code

CMCDragonkai

HTTP Streaming (or Chunked vs Store & Forward)

The standard way of understanding the HTTP protocol is via the request reply pattern. Each HTTP transaction consists of a finitely bounded HTTP request and a finitely bounded HTTP response.

However it's also possible for both parts of an HTTP 1.1 transaction to stream their possibly infinitely bounded data. The advantages is that the sender can send data that is beyond the sender's memory limit, and the receiver can act on

lopezjurip

Prerequisites

Make sure you have installed Homebrew and (Homebrew-Cask)[http://caskroom.io/].

# Install Homebrew
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

# Install Homebrew-cask
brew install caskroom/cask/brew-cask

bryangarza

module FilterElems where
import Data.List
import Control.Monad

-- abstract tuple comparison
sortTup f =
  case ord of
    EQ -> snd f
    _  -> ord
  where ord = fst f