Ideas.Common.Context

The Context datatype places a value in a context consisting of an environment with bindings and a point of focus. The datatype is an instance of the HasEnvironment type class (for accessing the environment) and the Navigator type class (for traversing the term).

Abstract data type

data Context a

Abstract data type for a context: a context stores an envrionent.

Instances

Typed a (Context a)

Typed a (Strategy (Context a))

Typed a (Rule (Context a))

Eq a => Eq (Context a)

Show a => Show (Context a)

HasEnvironment (Context a)

Navigator (Context a)

newContext :: ContextNavigator a -> Context a

Construct a context

fromContext :: Monad m => Context a -> m a

fromContextWith :: Monad m => (a -> b) -> Context a -> m b

fromContextWith2 :: Monad m => (a -> b -> c) -> Context a -> Context b -> m c

Context navigator

data ContextNavigator a

noNavigator :: a -> ContextNavigator a

navigator :: Uniplate a => a -> ContextNavigator a

termNavigator :: IsTerm a => a -> ContextNavigator a

Lifting

liftToContext :: LiftView f => f a -> f (Context a)

Lift a rule to operate on a term in a context

contextView :: View (Context a) (a, Context a)

use :: (LiftView f, IsTerm a, IsTerm b) => f a -> f (Context b)

useC :: (LiftView f, IsTerm a, IsTerm b) => f (Context a) -> f (Context b)

applyTop :: (a -> a) -> Context a -> Context a

Apply a function at top-level. Afterwards, try to return the focus to the old position

currentTerm :: Context a -> Maybe Term

changeTerm :: (Term -> Maybe Term) -> Context a -> Maybe (Context a)

replaceInContext :: a -> Context a -> Context a

currentInContext :: Context a -> Maybe a

changeInContext :: (a -> a) -> Context a -> Context a