philandstuff

Kush, an introduction to schedulers

about me

• I work for GDS
• Cabinet Office
• we started by building GOV.UK
  • replaced older sites like direct gov, business link
• we’re not just fixing websites
  • we also build and run digital services
  • working with depts across the country
  • eg: register to vote

tonymorris

I was just sitting in a doctor surgery 45 minutes ago with an orthopaedic spine surgeon, who is one of the few who has worked out how to use software to his advantage. We were measuring a deformity that the previous surgeon has created. After 20 minutes of drawing lines and measurements all over this DICOM image, the following happened

Access Violation at address 0xGOFUCKYOURSELF

…so now I have to go back in two weeks while he can restart a plan for a difficult corrective surgery.

3noch

#!/usr/bin/env stack
-- stack --install-ghc runghc --package turtle --package wreq

{-# LANGUAGE OverloadedStrings #-}

import qualified Control.Foldl as Fold
import Control.Lens ((^.))
import Control.Monad (when)
import Data.ByteString.Lazy (hPut)
import Data.Maybe (fromMaybe)

gneuvill

@Data(flavour = Flavour.FJ)
public abstract class Free<f, A> implements __2<Free.µ, f, A> {
    Free() {}
    interface Cases<f, A, R> {
        R Return(A a);
        R Suspend(__<f, A> fa);
        R Gosub(Sub<f, A, ?> sub);
    }
    abstract <R> R match(Cases<f, A, R> cases);

pchiusano

/**
 * In this version of `Traverse`, sequencing always goes through `List` (or some other canonical sequence type),
 * which can be done in a stack-safe manner using a balanced fold as in https://gist.github.com/pchiusano/7667597.
 * It's quite nice that `sequence` and `traverse` are now derived functions.
 */
trait Traverse[F[_]] extends Functor[F] {
  /** Inefficient but correct implementation of `toList` in terms of `mapAccumulate`. */
  def toList[A](f: F[A]): List[A] = mapAccumulate(f, List())((a, rbuf) => (a, a :: rbuf))._2.reverse
  
  /** The only function that must be implemented. Must be consistent with `map`. */                                                           

tonymorris

{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE DeriveFunctor #-}

import Control.Lens
import Prelude hiding (readFile, writeFile, print)
import qualified Prelude as Prelude(readFile, writeFile, print)

pchiusano

package scalaworld.interpreters

/*
This file shows a simple language, an interpreter, and two
partial evaluators for that language, along with a profiling suite.
*/

trait Expr // denotes a Vector[Double] => Vector[Double]

object Expr {

taktoa

with builtins;

rec {
  pkgs = import <nixpkgs> {};

  testGHC = pkgs.haskellPackages.ghcWithPackages (p: with p; [
    base base-orphans bifunctors comonad contravariant distributive
    tagged transformers
  ]);

paulp

// These lines go in ~/.sbt/0.13/global.sbt
watchSources ++= (
     (baseDirectory.value * "*.sbt").get
  ++ (baseDirectory.value / "project" * "*.scala").get
  ++ (baseDirectory.value / "project" * "*.sbt").get
)

addCommandAlias("rtu", "; reload ; test:update")
addCommandAlias("rtc", "; reload ; test:compile")
addCommandAlias("ru", "; reload ; update")

jdegoes

class Option<A> {
  protected Option() { }
}
interface App<F, A> {
  F proof();
}
class OptionF  {
  private OptionF() {}
  
  private static class AppOption<A> implements App<OptionF, A> {