| 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.
- data Restricted r v
- class Restriction r v where
- toRestricted :: v -> Maybe (Restricted r v)
- restrict :: v -> Restricted r v
- rvalue :: Restricted r v -> v
- data Nneg1
- data N1
- data N0
- data N254
- data Inf
- data Div4
- data Div5
Documentation
class Restriction r v where Source
A uniform way to restrict values.
Methods
toRestricted :: v -> Maybe (Restricted r v) Source
Create a restricted value. Returns Nothing if
the given value does not satisfy all restrictions.
restrict :: v -> Restricted r v Source
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 Source | |
| Restriction Div4 ByteString Source | |
| Integral a => Restriction (N1, Int32) a Source | |
| Integral a => Restriction (N1, Int64) a Source | |
| Integral a => Restriction (N1, Inf) a Source | |
| Restriction (N1, N254) String Source | |
| Restriction (N1, N254) ByteString Source | |
| Integral a => Restriction (N0, Int32) a Source | |
| Integral a => Restriction (N0, Int64) a Source | |
| Integral a => Restriction (N0, Inf) a Source | |
| Integral a => Restriction (Nneg1, Int32) a Source | |
| Integral a => Restriction (Nneg1, Int64) a Source | |
| Integral a => Restriction (Nneg1, Inf) a Source |
rvalue :: Restricted r v -> v Source
Get the actual value.
type level -1
type-level 1
Instances
| Show N1 Source | |
| Integral a => Restriction (N1, Int32) a Source | |
| Integral a => Restriction (N1, Int64) a Source | |
| Integral a => Restriction (N1, Inf) a Source | |
| Restriction (N1, N254) String Source | |
| Restriction (N1, N254) ByteString Source |
type-level 0
type-level 254
Instances
type-level infinity