Safe Haskell | None |
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- gSet :: (Data b, Typeable a) => a -> b -> b
- gReplace :: (Typeable a, Data b) => (a -> a) -> b -> b
- gFind :: (MonadPlus m, Data a, Typeable b) => a -> m b
- gFind' :: (Data a, Typeable b) => a -> b
- gModify :: (MonadState s m, Typeable a, Data s) => (a -> a) -> m ()
- gAsk :: (Data r, Typeable a, MonadReader r m, MonadPlus n) => (a -> n b) -> m (n b)
- gGet :: (Data s, Typeable a, MonadState s m, MonadPlus n) => (a -> n b) -> c -> m (n b)

# Documentation

gSet :: (Data b, Typeable a) => a -> b -> bSource

`gSet x y`

will traveral `x`

and replace
any instances of the type `a`

in its structure
with `y`

.

gReplace :: (Typeable a, Data b) => (a -> a) -> b -> bSource

`gReplace f b`

will traverse `x`

and will act on
any instance of the type `a`

in its structure with
the function `f`

.

gFind :: (MonadPlus m, Data a, Typeable b) => a -> m bSource

`gFind a`

will extract any elements of type `b`

from
`a`

's structure in accordance with the MonadPlus
instance, e.g. Maybe Foo will return the first Foo
found while [Foo] will return the list of Foos found.

gFind' :: (Data a, Typeable b) => a -> bSource

Acts as gFind but will throw an exception if nothing is found.

gModify :: (MonadState s m, Typeable a, Data s) => (a -> a) -> m ()Source

A generalized modify that will apply the modification function to the structure of the state.