Data.TypeList

The Module Data.TypeList is a collection of classes to manipulate lists of types, a.k.a. heterogeneous lists. Check the module Data.TypeList.MultiIndex for a concrete implementation of TypeList.

Documentation

class TypeList l where

Every TypeList has a Length. The Length is actually a type, and should be a Cardinal (see Data.Cardinal).

Associated Types

type Length l

Methods

length :: l -> Length l

Instances

TypeList Nil

TypeList l => TypeList (:|: e l)

class TypeList l => HeadTail l where

Associated Types

type Head l

type Tail l

Methods

head :: l -> Head l

tail :: l -> Tail l

(.|.) :: Head l -> Tail l -> l

Instances

TypeList l => HeadTail (:|: e l)

class Component l n where

Extracts the n-th component of the list l

Associated Types

type l :!!: n

Methods

(!!) :: l -> n -> l :!!: n

The second argument of !! should always be undefined :: n.

partialMap :: n -> ((l :!!: n) -> l :!!: n) -> l -> l

Applies the given function to one component of the list.

Instances

HeadTail l => Component l Zero

(HeadTail l, Component (Tail l) n) => Component l (Succ n)

class (TypeList l, TypeList l') => AppendList l l' where

A class for appending two TypeLists. The result of appending l and l' has type l :++: l'.

Associated Types

type l :++: l'

Methods

(<++>) :: l -> l' -> l :++: l'

Instances

TypeList l => AppendList Nil l

AppendList l l' => AppendList (:|: e l) l'

class (Cardinal n, TypeList l) => TakeList n l where

This is does for TakeList what take does for ordinary lists.

Associated Types

type Take n l

Methods

take :: n -> l -> Take n l

Instances

TakeList Zero Nil

TakeList Zero l => TakeList Zero (:|: e l)

TakeList n l => TakeList (Succ n) (:|: e l)

class (Cardinal n, TypeList l) => DropList n l where

This is does for TakeList what drop does for ordinary lists.

Associated Types

type Drop n l

Methods

drop :: n -> l -> Drop n l

Instances

DropList Zero Nil

DropList Zero l => DropList Zero (:|: e l)

DropList n l => DropList (Succ n) (:|: e l)

class (TypeList l, TypeList l') => TailRevList l l' where

Reverse l and append it in front of l'.

Associated Types

type TailRev l l'

Methods

rev :: l -> l' -> TailRev l l'

Instances

TypeList l => TailRevList Nil l

(TailRevList l (:|: e l'), TypeList l') => TailRevList (:|: e l) l'

class TypeList l => ReverseList l where

Reverse the TypeList l, and get Reverse l.

Associated Types

type Reverse l

Methods

reverse :: l -> Reverse l

Instances

ReverseList Nil

(TailRevList l Nil, TailRevList (:|: e l) Nil) => ReverseList (:|: e l)

class JoinList n l l' where

Join together TypeLists l and l' where the last n types of l coincide with the first n types of l'. The result has a the common n types eliminated.

Associated Types

type Join n l l'

Methods

join :: n -> l -> l' -> Join n l l'

Instances

(ReverseList (Drop n (Reverse l)), DropList n (Reverse l), ReverseList l, AppendList (Reverse (Drop n (Reverse l))) (Drop n l'), DropList n l', ~ * (Reverse (Take n (Reverse l))) (Take n l')) => JoinList n l l'

class Extend l l' where

Extend the list l to l' by adding the necessary extension Ext l l'.

Associated Types

type Ext l l'

Methods

extend :: l -> Ext l l' -> l'

Instances

Extend Nil l'

Extend l l' => Extend (:|: e l) (:|: e l')