Portability | non-portable (GHC Extensions) |
---|---|
Stability | experimental |
Maintainer | Patrick Bahr <paba@diku.dk> and Tom Hvitved <hvitved@diku.dk> |
This module defines an abstract notion of (bound) variables in compositional data types, and scoped substitution. Capture-avoidance is not taken into account.
- class HasVars f v where
- type Subst f v = CxtSubst NoHole () f v
- type CxtSubst h a f v = Map v (Cxt h f a)
- varsToHoles :: (Functor f, HasVars f v, Eq v) => Term f -> Context f v
- containsVar :: (Eq v, HasVars f v, Foldable f, Functor f) => v -> Cxt h f a -> Bool
- variables :: (Ord v, HasVars f v, Foldable f, Functor f) => Cxt h f a -> Set v
- variableList :: (Ord v, HasVars f v, Foldable f, Functor f) => Cxt h f a -> [v]
- variables' :: (Ord v, HasVars f v, Foldable f, Functor f) => Const f -> Set v
- substVars :: SubstVars v t a => (v -> Maybe t) -> a -> a
- appSubst :: (Ord v, SubstVars v t a) => Map v t -> a -> a
- compSubst :: (Ord v, HasVars f v, Functor f) => CxtSubst h a f v -> CxtSubst h a f v -> CxtSubst h a f v
Documentation
This multiparameter class defines functors with variables. An instance
HasVar f v
denotes that values over f
might contain and bind variables of
type v
.
Indicates whether the f
constructor is a variable.
Indicates the set of variables bound by the f
constructor.
type Subst f v = CxtSubst NoHole () f vSource
This type represents substitutions of terms, i.e. finite mappings from variables to terms.
type CxtSubst h a f v = Map v (Cxt h f a)Source
This type represents substitutions of contexts, i.e. finite mappings from variables to contexts.
varsToHoles :: (Functor f, HasVars f v, Eq v) => Term f -> Context f vSource
Convert variables to holes, except those that are bound.
containsVar :: (Eq v, HasVars f v, Foldable f, Functor f) => v -> Cxt h f a -> BoolSource
This function checks whether a variable is contained in a context.
variables :: (Ord v, HasVars f v, Foldable f, Functor f) => Cxt h f a -> Set vSource
This function computes the set of variables occurring in a context.
variableList :: (Ord v, HasVars f v, Foldable f, Functor f) => Cxt h f a -> [v]Source
This function computes the list of variables occurring in a context.