Hell is a shell scripting language that is a tiny dialect of Haskell that I wrote for my own shell scripting purposes. #!/usr/bin/env hell main = do Text.putStrLn "Please enter your name and hit ENTER:" name <- Text.getLine Text.putStrLn "Thanks, your name is: " Text.putStrLn name Overview Use a faithful Haskell syntax parser. It has no imports/modules/packages. It doesn’t support recursive defini

This set of slides sketches out the implementation of Hell, in technical detail. I do tend to switch between the slides, old code, and the present code, so bear with me. It's more about the ideas. If you want to see a complete implementation, the complete implementation of Hell is one file, which you can look through easily. There are a few limits on the language; no imports, no polymorphism (poly

“Impractical”, “academic”, “niche”. These are a few of the reactions I get when someone discovers that my favourite programming language is Haskell, and not only my favourite in some sort of intellectually-masturbatory way, but favourite for building things, real things, mostly involving web servers. Hobby projects would be one thing, but it gets worse: I have actual teams at Converge working in H

> We can generalise this idea of being forced to handle the failure cases by saying that Haskell makes us write total functions rather than partial functions.Haskell doesn't prevent endless recursion. (try e.g. `main = main`) As the typed FP ecosystem is moving towards dependent typing (Agda, Idris, Lean), this becomes an issue, because you don't want the type checker to run indefinitely. The many

A lightning post on logic programming in Haskell to construct a workout weekly schedule given the set of exercises, days and constraints. #haskell I have recently started doing some outdoors bodyweight workouts. I also want to start running again, but I’m recovering from a minor knee injury until the start of next month. Tonight I decided to put together a weekly schedule to start following next m

For the past few days, I have been toying with an idea for a board game. To test it out, I wanted to write a simple implementation of it. Here’s an example of a type we might need in a critical phase of the game. In[1]: -- | A quote for a proposal. data Quote = Quote { _proposal :: Proposal , _premium :: Int , _share :: Int } In that phase, values of this type need to be communicated back and fort

The algebra (and calculus!) of algebraic data types Joel Burget Note: This article assumes some introductory Haskell knowledge. Introduction Just as algebra is fundamental to the whole of mathematics, algebraic data types (ADTs) are fundamental to many common functional programming languages. They’re the primitives upon which all of our richer data structures are built, including everything from s

Shake is... A build system – an alternative to make, Scons, Ant etc. Reliable and robust – having been relied on commercially for over five years. Powerful – letting you express the problem precisely and directly. Fast to run – both to build from scratch and to rebuild. Large build systems written using Shake tend to be significantly simpler, while also running faster. If your project can use a ca

Haskell was designed as a practical, purely functional programming language. It's famous for its monads and its type system, but I keep coming back to it because of its elegance. Haskell makes coding a real joy for me. -- Single line comments start with two dashes. {- Multiline comments can be enclosed in a block like this. -} ---------------------------------------------------- -- 1. Primitive Da

Implementing a JIT Compiled Language with Haskell and LLVM Adapted by Stephen Diehl ( @smdiehl ) This is an open source project hosted on Github. Corrections and feedback always welcome. Version 1: December 25, 2013 Version 2: May 8, 2017 The written text licensed under the LLVM License and is adapted from the original LLVM documentation. The new Haskell source is released under the MIT license. C