This module defines Uniplate
/ Biplate
instances for every type with a
Data
instance. Using GHC, Data can be derived automatically with:
data Expr = Var Int | Neg Expr | Add Expr Expr deriving (Data,Typeable)
All the Uniplate operations defined in Data.Generics.Uniplate.Operations can be used.
For faster performance (5x faster, but requires writing instances) switch to
Data.Generics.Uniplate.Direct. If you get instance conflicts
when using both Data
and Direct
, switch to Data.Generics.Uniplate.DataOnly.
- module Data.Generics.Uniplate.Operations
- transformBis :: forall a. Data a => [[Transformer]] -> a -> a
- data Transformer
- transformer :: Data a => (a -> a) -> Transformer
Documentation
transformBis :: forall a. Data a => [[Transformer]] -> a -> aSource
Apply a sequence of transformations in order. This function obeys the equivalence:
transformBis [[transformer f],[transformer g],...] == transformBi f . transformBi g . ...
Each item of type [Transformer]
is applied in turn, right to left. Within each
[Transformer]
, the individual Transformer
values may be interleaved.
The implementation will attempt to perform fusion, and avoid walking any part of the data structure more than necessary. To further improve performance, you may wish to partially apply the first argument, which will calculate information about the relationship between the transformations.
data Transformer Source
transformer :: Data a => (a -> a) -> TransformerSource
Wrap up a (a -> a)
transformation function, to use with transformBis