LText.Internal.Inference

Documentation

newtype Context

Constructors

Context (Map ExprVar Prenex)

Instances

Bindable Set TypeVar Context

Substitutable Map TypeVar Type Context

remove :: Context -> String -> Context

generalize :: Context -> Type -> Prenex

Binds free type variables as universally quantified

data TIState

Constructors

TIState

Fields

tiSupply :: Int

tiSubst :: Subst TypeVar Type

type TI m a = ExceptT String (StateT TIState m) a

Inference Monad

runTI :: (Monad m, MonadError String m) => StateT TIState m a -> m a

newTyVar :: (Monad m, MonadState TIState m, MonadError String m) => TypeVar -> m Type

instantiate :: (Monad m, MonadState TIState m, MonadError String m) => Prenex -> m Type

Replaces bound type variables with free, fresh ones

mgu :: (Monad m, MonadState TIState m, MonadError String m) => Type -> Type -> m (Subst TypeVar Type)

Most general unifier

varBind :: (Monad m, MonadState TIState m, MonadError String m) => TypeVar -> Type -> m (Subst TypeVar Type)

Makes a substitution [x -> t]

ti :: (Monad m, MonadState TIState m, MonadError String m) => Context -> Expr -> m (Subst TypeVar Type, Type)

Type inference function

typeInference :: (Monad m, MonadState TIState m, MonadError String m) => Context -> Expr -> m Type

test :: (Monad m, MonadIO m) => Expr -> m ()