narc-0.1.2: Query SQL databases using Nested Relational Calculus embedded in Haskell.

Database.Narc.Type

Synopsis

Documentation

type TyVar = Int Source

data Type Source

Constructors

TBool
TNum
TString
TUnit
TList Type
TArr Type Type
TRecord [(String, Type)]
TVar TyVar

Instances

Eq Type
Show Type
Arbitrary Type

type QType = ([TyVar], Type)Source

type TySubst = [(Int, Type)]Source

type TyEnv = [(Var, QType)]Source

emptyTySubst :: TySubst Source

applyTySubst :: TySubst -> Type -> Type Source

ftvs: free type variables

ftvsSubst: the free type variables of a type substitution--that is, the type variables free in the types in the range of the substitution.

occurs x ty: does variable x appear in type ty? (Note there are no type-variable binders).

normalizeType :: Type -> State (Int, [(Int, Int)]) Type Source

normalizeType: Renumber all the type variables in a normal way to allow comparing types.

instanceOf :: Type -> Type -> Failure ()Source

unify :: Type -> Type -> Failure TySubst Source

unifyAll :: [Type] -> Failure TySubst Source

composeTySubst :: [TySubst] -> Failure TySubst Source

disjoinSubst :: TySubst -> TySubst -> TySubst Source