Daniel Díaz Carrete danidiaz

Rust in Large Organizations

Initially taken by Niko Matsakis and lightly edited by Ryan Levick

Agenda

Introductions
Cargo inside large build systems
FFI
Foundations and financial support

Introduction

I was recently asked to explain why I felt disappointed by Haskell, as a language. And, well. Crucified for crucified, I might as well criticise Haskell publicly.

First though, I need to make it explicit that I claim no particular skill with the language - I will in fact vehemently (and convincingly!) argue that I'm a terrible Haskell programmer. And what I'm about to explain is not meant as The Truth, but my current understanding, potentially flawed, incomplete, or flat out incorrect. I welcome any attempt at proving me wrong, because when I dislike something that so many clever people worship, it's usually because I missed an important detail.

Another important point is that this is not meant to convey the idea that Haskell is a bad language. I do feel, however, that the vocal, and sometimes aggressive, reverence in which it's held might lead people to have unreasonable expectations. It certainly was my case, and the reason I'm writing this.

Type classes

I love the concept of type class

Strictness in Kinds

Let's tweak GHC's RuntimeRep stuff to try adding information about strictness. This information could be helpful for avoiding evaluating thunks that are guaranteed to already be evaluated. Presently, RuntimeRep is defined as:

data RuntimeRep

= LiftedRep

	{-# LANGUAGE PolyKinds #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE ConstraintKinds #-}
	{-# LANGUAGE Rank2Types #-}
	{-# LANGUAGE GADTs #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE FlexibleContexts #-}
	{-# LANGUAGE TypeInType #-}
	{-# LANGUAGE TypeApplications #-}
	{-# LANGUAGE AllowAmbiguousTypes #-}

	-- A concrete use case for the type which is to '(->)' as 'Day' is to '(,)'.
	-- I call it "FunDay", but I don't know what its proper name is. I've been
	-- trying to find a use for 'FunDay', and I think I've found a pretty neat one.

	{-# LANGUAGE FlexibleContexts, FlexibleInstances, PolyKinds, RankNTypes, TypeSynonymInstances #-}
	module Main where
	import Test.DocTest

	import Control.Monad.Except
	import Control.Monad.Reader

	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE DeriveGeneric #-}
	{-# LANGUAGE NamedFieldPuns #-}
	{-# LANGUAGE TypeApplications #-}
	module HiggledyHedgehog where

	import Control.Lens
	import Data.Generic.HKD
	import GHC.Generics (Generic)
	import Hedgehog

	{-# LANGUAGE
	GADTs
	, DataKinds
	, PolyKinds
	, RankNTypes
	, TypeOperators
	, KindSignatures
	, TypeApplications
	, FlexibleContexts
	, FlexibleInstances

	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE FunctionalDependencies #-}
	{-# LANGUAGE GADTs #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE TypeInType #-}
	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE UndecidableInstances #-}
	{-# OPTIONS_GHC -Wall #-}

	let
	nixpkgs-src = builtins.fetchTarball {
	url = "https://github.com/NixOS/nixpkgs-channels/archive/f197f57bd336746b53e5f1668ac7df1b63da7c9f.tar.gz";
	sha256 = "0cj4h39fhrm0nzxgfcjxy457zhi2rajpgm6abas816srmr4bb6nn";
	};
	semantic-src = builtins.fetchTarball {
	url = "https://github.com/github/semantic/archive/78dad094fa2380aef36cabd48d57f6122f1034ec.tar.gz";
	sha256 = "0bk7f96fm9928nc2yv85cwchk43xh4yikbiqg7ngba5q6gj7xy04";
	};
	pkgs = import nixpkgs-src { config.allowBroken = true; };