View haskell-billing-server.lhs
Writing a billing system in Haskell, using Stripe and Heroku
===
*This post is written in literate Haskell, meaning the source can be turned
into a blogpost or a working program. You can view the [source][source].
[source]: https://gist.github.com/gatlin/7754289
Normally clients pay me with checks, but recently one informed me that they
really really really like *really really* super prefer some kind of online
View io.hs
{-# LANGUAGE RankNTypes #-}
import Prelude hiding (IO, getLine)
import qualified Prelude as P
import System.IO.Unsafe
-- * The Foreign Function Interface
-- | FFI values permit interfacing with foreign functions, such as low-level IO
-- operations, memory management operations, or bindings to other user-level
View install-arch-linux-rpi-zero-w.sh
#!/bin/sh -exu
dev=$1
cd $(mktemp -d)
function umountboot {
umount boot || true
umount root || true
}
# RPi1/Zero (armv6h):
View typed-racket-monads.md

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.

View uninstall-haskell-osx.sh
#!/bin/bash
# source: http://www.haskell.org/pipermail/haskell-cafe/2011-March/090170.html
sudo rm -rf /Library/Frameworks/GHC.framework
sudo rm -rf /Library/Frameworks/HaskellPlatform.framework
sudo rm -rf /Library/Haskell
rm -rf .cabal
rm -rf .ghc
rm -rf ~/Library/Haskell
View pid.lhs
PID controller in Haskell
===
A major project I want to embark on at some point in the future is making a
quadrotor. I've made one before but I was at the mercy of a lot of off-the-shelf
software that I'm not altogether sure was entirely correct, either.
So I want to eventually program a quadrotor (or similarly awesome robot thing)
and I would really enjoy doing it in Haskell. It has a low footprint and is
already used in other real time settings.
View bikemath.md

Bike Math!

Note: For the sake of clarity I'll probably write things you already know. It's just as much to eliminate communication errors as it is for me to keep track of what the fuck I'm even talking about. It does not imply any kind of judgment of what I assume about you :)

Here's the math behind gears and how they are used to efficiently rotate wheels. The same principles underlie how cars work but the mechanisms are

View free-compiler.hs
{-|
- Example of using free constructions to build a flexible little compiler.
-
- The goal here is not necessarily efficiency but readability and flexibility.
-
- The language grammar is represented by an ADT; however, instead of
- recursively referring to itself it instead references a type variable.
-
- We derive instances of 'Functor' and 'Traversable' for this type.
-
View yet-another-conway.hs
{-# LANGUAGE DeriveFunctor #-}
import Control.Applicative
import Control.Comonad
import Control.Monad (forM_)
-- These two typeclasses probably make some people groan.
class LeftRight t where
left :: t a -> t a
View imperative.lhs
How to add imperative programming to a pure functional language
===
Many people bemoan languages such as Haskell for not supporting imperative
programming; they decry the need for math in their computer science.
![Math? In my computer? Yeah right.](http://i.imgur.com/YDIaEPB.jpg)
I'm here to tell you that not only does Haskell make imperative programming a
cinch, but safe and correct as well. Follow along! This post is written in