| Safe Haskell | Safe-Infered |
|---|
Top.Types.Unification
Description
A unification algorithm for types, which can take a list of (ordered) type synonyms into account.
- data UnificationError
- mgu :: Tp -> Tp -> Either UnificationError MapSubstitution
- mguWithTypeSynonyms :: OrderedTypeSynonyms -> Tp -> Tp -> Either UnificationError (Bool, MapSubstitution)
- equalUnderTypeSynonyms :: OrderedTypeSynonyms -> Tp -> Tp -> Maybe Tp
- unifiable :: OrderedTypeSynonyms -> Tp -> Tp -> Bool
- unifiableList :: OrderedTypeSynonyms -> Tps -> Bool
Documentation
data UnificationError Source
There are two reasons why two types cannot be unified: either two (different) type constants clash (they should be the same), or a type variable should be unified with a composed type that contains this same type variable.
Constructors
| ConstantClash String String | |
| InfiniteType Int |
Instances
mgu :: Tp -> Tp -> Either UnificationError MapSubstitutionSource
The most general unification (substitution) of two types.
mguWithTypeSynonyms :: OrderedTypeSynonyms -> Tp -> Tp -> Either UnificationError (Bool, MapSubstitution)Source
equalUnderTypeSynonyms :: OrderedTypeSynonyms -> Tp -> Tp -> Maybe TpSource
Find the most general type for two types that are equal under type synonyms (i.e., the least number of expansions)
unifiable :: OrderedTypeSynonyms -> Tp -> Tp -> BoolSource
Given a set of (ordered) type synonyms, can two types be unified?
unifiableList :: OrderedTypeSynonyms -> Tps -> BoolSource
Same as unifiable, but takes as input a list of types