dmwit

{-# LANGUAGE TypeFamilies #-}

type family StateFor a
type instance StateFor Integer = ()
type instance StateFor (a, b) = (StateFor a, StateFor b)
type instance StateFor [a] = (Integer, [StateFor a])

class ReadObj a where
  readObj :: StateFor a -> [[String]] -> (a, [[String]])

dmwit

let b:align_language_pragma = 0
setlocal cpoptions+=M
iabbrev <buffer> H# {-# #-}<Left><Left><Left><Left>
iabbrev <buffer> HA Applicative
iabbrev <buffer> HB Bounded, Enum, Eq, Ord, Read, Show
iabbrev <buffer> HBS ByteString
iabbrev <buffer> HC Control
iabbrev <buffer> HD Data
iabbrev <buffer> Hd deriving ()<Left>
iabbrev <buffer> Hda data =<CR>deriving (Eq, Ord, Read, Show)<Up><End><Left><Left>

dmwit

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE TypeApplications #-}

data K = A | B | C
data Foo a where
	FooAny :: Foo a
	FooAB :: Foo (Fam a)

dmwit

class Y xs where
	type ToS xs :: TreeS
	y :: HTree_ (ToS xs) -> HTreeS xs (ToS xs)

instance Y TLeaf where
	type ToS TLeaf = TLeafS
	y HLeaf_ = x

dmwit

foldb1 op = foldb' where
    pairwise (x:y:rest) = op x y : pairwise rest
    pairwise shortList  = shortList
    foldb'   xs@(_:_:_) = foldb' (pairwise xs)
    foldb'   [x]        = x
foldb op def xs = foldb1 op (def:xs)

dmwit

fs :: Bool -> Int -> Int
fs False = (+1)
fs True = (*3)

vals :: Bool -> Int
vals False = 10
vals True = 20

fOfVals :: Bool -> Int
fOfVals = fs <*> vals

dmwit

data Zero = Zero deriving Show
data Succ n = Succ deriving Show

class Foo a where foo :: a
instance Foo Zero where foo = Zero
instance Foo n => Foo (Succ n) where foo = Succ

type Two zero = Succ (Succ zero)
type Four zero = Two (Two zero)
type Eight zero = Four (Four zero)

dmwit

import Data.List
import System.Environment

data SizedTree a = Node Integer a [SizedTree a] deriving (Eq, Ord, Read, Show)
type Stream a = [SizedTree a]

indexT :: Integer -> SizedTree a -> a
indexT 0 (Node _ v _) = v
indexT n (Node _ _ vs) = indexS (n-1) vs

dmwit

import Data.List
import System.Environment

data SizedTree a = Node Integer a [SizedTree a] deriving (Eq, Ord, Read, Show)
type Stream a = [SizedTree a]

indexT :: Integer -> SizedTree a -> a
indexT 0 (Node _ v _) = v
indexT n (Node _ _ vs) = indexS (n-1) vs

dmwit

#include <unistd.h>

int main() {
	char *args[3] = {"notsleep", "10", NULL};
	return execv("/usr/bin/sleep", args);
}