Copyright	(c) 2011-2013 Toralf Wittner
License	MIT
Maintainer	Toralf Wittner <tw@dtex.org>
Stability	experimental
Portability	non-portable
Safe Haskell	Safe
Language	Haskell98

Data.Restricted

Description

Type-level restricted data. This module allows for type declarations which embed certain restrictions, such as value bounds. E.g. Restricted N0 N1 Int denotes an Int which can only have values [0 .. 1]. When creating such a value, the constructor functions restrict or toRestricted ensure that the restrictions are obeyed. Code that consumes restricted types does not need to check the constraints.

N.B. This module is more or less tailored to be used within ZMQ3. Therefore the provided type level restrictions are limited.

Synopsis

Documentation

data Restricted r v #

Type level restriction.

Instances

Show v => Show (Restricted r v) #
Methods showsPrec :: Int -> Restricted r v -> ShowS # show :: Restricted r v -> String # showList :: [Restricted r v] -> ShowS #

class Restriction r v where #

A uniform way to restrict values.

Minimal complete definition

toRestricted, restrict

Methods

toRestricted :: v -> Maybe (Restricted r v) #

Create a restricted value. Returns Nothing if the given value does not satisfy all restrictions.

restrict :: v -> Restricted r v #

Create a restricted value. If the given value does not satisfy the restrictions, a modified variant is used instead, e.g. if an integer is larger than the upper bound, the upper bound value is used.

Instances

Restriction Div5 ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted Div5 ByteString) # restrict :: ByteString -> Restricted Div5 ByteString #
Restriction Div4 ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted Div4 ByteString) # restrict :: ByteString -> Restricted Div4 ByteString #
Integral a => Restriction (N1, Int32) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Int32) a) # restrict :: a -> Restricted (N1, Int32) a #
Integral a => Restriction (N1, Int64) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Int64) a) # restrict :: a -> Restricted (N1, Int64) a #
Integral a => Restriction (N1, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Inf) a) # restrict :: a -> Restricted (N1, Inf) a #
Restriction (N1, N254) String #
Methods toRestricted :: String -> Maybe (Restricted (N1, N254) String) # restrict :: String -> Restricted (N1, N254) String #
Restriction (N1, N254) ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted (N1, N254) ByteString) # restrict :: ByteString -> Restricted (N1, N254) ByteString #
Integral a => Restriction (N0, Int32) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Int32) a) # restrict :: a -> Restricted (N0, Int32) a #
Integral a => Restriction (N0, Int64) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Int64) a) # restrict :: a -> Restricted (N0, Int64) a #
Integral a => Restriction (N0, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Inf) a) # restrict :: a -> Restricted (N0, Inf) a #
Integral a => Restriction (Nneg1, Int32) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Int32) a) # restrict :: a -> Restricted (Nneg1, Int32) a #
Integral a => Restriction (Nneg1, Int64) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Int64) a) # restrict :: a -> Restricted (Nneg1, Int64) a #
Integral a => Restriction (Nneg1, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Inf) a) # restrict :: a -> Restricted (Nneg1, Inf) a #

rvalue :: Restricted r v -> v #

Get the actual value.

data Nneg1 #

type level -1

Instances

Show Nneg1 #
Methods showsPrec :: Int -> Nneg1 -> ShowS # show :: Nneg1 -> String # showList :: [Nneg1] -> ShowS #
Integral a => Restriction (Nneg1, Int32) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Int32) a) # restrict :: a -> Restricted (Nneg1, Int32) a #
Integral a => Restriction (Nneg1, Int64) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Int64) a) # restrict :: a -> Restricted (Nneg1, Int64) a #
Integral a => Restriction (Nneg1, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Inf) a) # restrict :: a -> Restricted (Nneg1, Inf) a #

data N1 #

type-level 1

Instances

Show N1 #
Methods showsPrec :: Int -> N1 -> ShowS # show :: N1 -> String # showList :: [N1] -> ShowS #
Integral a => Restriction (N1, Int32) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Int32) a) # restrict :: a -> Restricted (N1, Int32) a #
Integral a => Restriction (N1, Int64) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Int64) a) # restrict :: a -> Restricted (N1, Int64) a #
Integral a => Restriction (N1, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Inf) a) # restrict :: a -> Restricted (N1, Inf) a #
Restriction (N1, N254) String #
Methods toRestricted :: String -> Maybe (Restricted (N1, N254) String) # restrict :: String -> Restricted (N1, N254) String #
Restriction (N1, N254) ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted (N1, N254) ByteString) # restrict :: ByteString -> Restricted (N1, N254) ByteString #

data N0 #

type-level 0

Instances

Show N0 #
Methods showsPrec :: Int -> N0 -> ShowS # show :: N0 -> String # showList :: [N0] -> ShowS #
Integral a => Restriction (N0, Int32) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Int32) a) # restrict :: a -> Restricted (N0, Int32) a #
Integral a => Restriction (N0, Int64) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Int64) a) # restrict :: a -> Restricted (N0, Int64) a #
Integral a => Restriction (N0, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Inf) a) # restrict :: a -> Restricted (N0, Inf) a #

data N254 #

type-level 254

Instances

Show N254 #
Methods showsPrec :: Int -> N254 -> ShowS # show :: N254 -> String # showList :: [N254] -> ShowS #
Restriction (N1, N254) String #
Methods toRestricted :: String -> Maybe (Restricted (N1, N254) String) # restrict :: String -> Restricted (N1, N254) String #
Restriction (N1, N254) ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted (N1, N254) ByteString) # restrict :: ByteString -> Restricted (N1, N254) ByteString #

data Inf #

type-level infinity

Instances

Show Inf #
Methods showsPrec :: Int -> Inf -> ShowS # show :: Inf -> String # showList :: [Inf] -> ShowS #
Integral a => Restriction (N1, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (N1, Inf) a) # restrict :: a -> Restricted (N1, Inf) a #
Integral a => Restriction (N0, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (N0, Inf) a) # restrict :: a -> Restricted (N0, Inf) a #
Integral a => Restriction (Nneg1, Inf) a #
Methods toRestricted :: a -> Maybe (Restricted (Nneg1, Inf) a) # restrict :: a -> Restricted (Nneg1, Inf) a #

data Div4 #

divisable by 4

Instances

Show Div4 #
Methods showsPrec :: Int -> Div4 -> ShowS # show :: Div4 -> String # showList :: [Div4] -> ShowS #
Restriction Div4 ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted Div4 ByteString) # restrict :: ByteString -> Restricted Div4 ByteString #

data Div5 #

divisable by 5

Instances

Show Div5 #
Methods showsPrec :: Int -> Div5 -> ShowS # show :: Div5 -> String # showList :: [Div5] -> ShowS #
Restriction Div5 ByteString #
Methods toRestricted :: ByteString -> Maybe (Restricted Div5 ByteString) # restrict :: ByteString -> Restricted Div5 ByteString #