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Data.Generics.PlateTypeable |
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Description |
RECOMMENDATION: 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
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Synopsis |
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Documentation |
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module Data.Generics.Biplate |
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module Data.Typeable |
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The Class
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class PlateAll from to where | Source |
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This class represents going from the container type to the target.
This class should only be constructed with plate, |+ and |-
| | Methods | plateAll :: from -> Type from to | Source |
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This function is used to write a Uniplate instance from a PlateAll one
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The Combinators
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plate :: from -> Type from to | Source |
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The main combinator used to start the chain.
The following rule can be used for optimisation:
plate Ctor |- x == plate (Ctor x)
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the field to the right may contain the target.
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(|-) :: Type (item -> from) to -> item -> Type from to | Source |
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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.
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Produced by Haddock version 2.6.1 |