Copyright	Copyright (C) 2015 Kyle Carter
License	BSD3
Maintainer	Kyle Carter <kylcarte@indiana.edu>
Stability	experimental
Portability	RankNTypes
Safe Haskell	None
Language	Haskell2010

Type.Family.List

Description

Convenient aliases and type families for working with type-level lists.

Synopsis

Documentation

type Ø = `[]` Source

type (:<) = (:) infixr 5 Source

type Only a = `[a]` Source

Type-level singleton list.

type family as ++ bs :: [k] infixr 5 Source

Appends two type-level lists.

Equations

Ø ++ bs = bs
(a :< as) ++ bs = a :< (as ++ bs)

type family as >: a :: [k] infixl 6 Source

Type-level list snoc.

Equations

Ø >: a = Only a
(b :< as) >: a = b :< (as >: a)

type family Reverse as :: [k] Source

Equations

Reverse Ø = Ø
Reverse (a :< as) = Reverse as >: a

type family Init' a as :: [k] Source

Equations

Init' a Ø = Ø
Init' a (b :< as) = a :< Init' b as

type family Last' a as :: k Source

Equations

Last' a Ø = a
Last' a (b :< as) = Last' b as

Takes a type-level list of Constraints to a single Constraint, where ListC cs holds iff all elements of cs hold.

Equations

ListC Ø = ØC
ListC (c :< cs) = (c, ListC cs)

type family f <$> a :: [l] infixr 4 Source

Map an (f :: k -> l) over a type-level list (as :: [k]), giving a list (bs :: [l]).

Equations

f <$> Ø = Ø
f <$> (a :< as) = f a :< (f <$> as)

type family f <&> a :: [l] infixl 5 Source

Map a list of (fs :: [k -> l]) over a single (a :: k), giving a list (bs :: [l]).

Equations

Ø <&> a = Ø
(f :< fs) <&> a = f a :< (fs <&> a)

type family f <*> a :: [l] infixr 4 Source

Equations

fs <*> Ø = Ø
fs <> (a :< as) = (fs <&> a) ++ (fs <> as)

(==) :: Eq a => a -> a -> Bool