tonymorris

{-# OPTIONS_GHC -Wall #-}
{-# LANGUAGE TemplateHaskell #-}

import Control.Lens

data These a b =
  This a
  | That b
  | Both a b
  deriving (Eq, Show)

tonymorris

{-# LANGUAGE LambdaCase #-}

import Control.Lens

data Blah a =
  Blah1 a
  | Blah2 a
  | BlahS String
  deriving (Eq, Show)

tonymorris

// >>> given([notnull 1,null,notnull 3])
// null
// >>> given([notnull 1,notnull 2,notnull 3])
// notnull [1,2,3]
given(list) {
  var r = List.empty
  for(var i = 0; i < list.length; i++) {
    if(list[i] == null) 
      return null
    else 

tonymorris

FROM ubuntu:16.04

RUN apt-get update

RUN apt-get install -y libreoffice imagemagick ghostscript rsync bash pdftk texlive-xetex texlive-luatex ttf-dejavu sudo zlib1g-dev ghc cabal-install

RUN export TZ=Australia/Brisbane
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
RUN export LANG=C.UTF-8
RUN grep write /etc/ImageMagick-6/policy.xml

tonymorris

Optics By Example Cheat Sheets

The following are appendices from Optics By Example, a comprehensive guide to optics from beginner to advanced! If you like the content below, there's plenty more where that came from; pick up the book!

• Operators
• Composition Guide
• Substitution Guide
• Optical Constarints and Types

Operator Cheat Sheet

tonymorris

// Which of f or g are more readable, and if possible, why?

def f(x: Seq[Int]): Int =
  x.toList match {
    case Nil => 99
    case lst => lst.sum
  }

def g(x: Seq[Int]): Int =
  x.toList match {

tonymorris

{-# OPTIONS_GHC -Wall #-}
{-# LANGUAGE TemplateHaskell #-}

import Control.Lens
import Data.Bool

data DataTypeWithMillionsOfConstructors =
  DataTypeWithMillionsOfConstructors0
  | DataTypeWithMillionsOfConstructors1
  | DataTypeWithMillionsOfConstructors2

tonymorris

case class ListZipper[A](lefts: List[A], focus: A, rights: List[A]) {
  def map[B](f: A => B): ListZipper[B] =
    ListZipper(lefts map f, f(focus), rights map f)

  def ap[B](f: ListZipper[A => B]): ListZipper[B] =
    ListZipper(
      f.lefts.zip(lefts).map { case (ff, aa) => ff(aa) }
    , f.focus(focus)
    , f.rights.zip(rights).map { case (ff, aa) => ff(aa) }
    )

tonymorris

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www8.garmin.com/xmlschemas/FlightPlan/v1" xmlns:fp="http://www8.garmin.com/xmlschemas/FlightPlan/v1" targetNamespace="http://www8.garmin.com/xmlschemas/FlightPlan/v1" elementFormDefault="qualified">
  <xsd:annotation>
    <xsd:documentation>
      To transform a FlightPlan v1 XML document to GPX format a stylesheet will exist
      on the Garmin website.
    </xsd:documentation>
  </xsd:annotation>
  <xsd:element name="flight-plan" type="FlightPlan_t">
    <xsd:key name="WaypointIdKey">

tonymorris

data ZeroOrTwo a =
  Zero
  | Two a a

instance Functor ZeroOrTwo where
  fmap _ Zero =
    Zero
  fmap f (Two a1 a2) =
    Two (f a1) (f a2)