Safe Haskell | None |
---|---|
Language | Haskell98 |
Data.Generics.PlateTypeable
Description
Deprecated: Use Data.Generics.Uniplate.Typeable instead
DEPRECATED: Use Data.Generics.Uniplate.Typeable instead.
This module supplies a method for writing Biplate
instances more easily.
To take an example:
data Expr = Var Int | Neg Expr | Add Expr Expr instance Typeable Expr where ... instance (Typeable a, Uniplate a) => PlateAll Expr a where plateAll (Var x ) = plate Var |- x plateAll (Neg x ) = plate Neg |+ x plateAll (Add x y) = plate Add |+ x |+ y instance Uniplate Expr where uniplate = uniplateAll
- module Data.Generics.Biplate
- module Data.Typeable
- class PlateAll from to where
- uniplateAll :: PlateAll a b => a -> (Str b, Str b -> a)
- plate :: from -> Type from to
- (|+) :: (Typeable item, Typeable to, PlateAll item to) => Type (item -> from) to -> item -> Type from to
- (|-) :: Type (item -> from) to -> item -> Type from to
Documentation
module Data.Generics.Biplate
module Data.Typeable
The Class
class PlateAll from to where #
This class represents going from the container type to the target.
Minimal complete definition
Instances
uniplateAll :: PlateAll a b => a -> (Str b, Str b -> a) #
The Combinators
plate :: from -> Type from to #
The main combinator used to start the chain.
The following rule can be used for optimisation:
plate Ctor |- x == plate (Ctor x)
(|+) :: (Typeable item, Typeable to, PlateAll item to) => Type (item -> from) to -> item -> Type from to #
the field to the right may contain the target.
(|-) :: Type (item -> from) to -> item -> Type from to #
The field to the right does not contain the target. This can be used as either an optimisation, or more commonly for excluding primitives such as Int.