Language.Futhark.TypeChecker.Types

Type checker building blocks that do not involve unification.

Documentation

checkTypeExp :: MonadTypeChecker m => TypeExp Name -> m (TypeExp VName, [VName], StructRetType, Liftedness)

Check a type expression, producing:

• The checked expression.
• Size variables for any anonymous sizes in the expression.
• The elaborated type.
• The liftedness of the type.

renameRetType :: MonadTypeChecker m => StructRetType -> m StructRetType

Ensure that the dimensions of the RetType are unique by generating new names for them. This is to avoid name capture.

unifyTypesU :: (Monoid als, ArrayDim dim) => (Uniqueness -> Uniqueness -> Maybe Uniqueness) -> TypeBase dim als -> TypeBase dim als -> Maybe (TypeBase dim als)

unifyTypes uf t1 t2 attempts to unify t1 and t2. If unification cannot happen, Nothing is returned, otherwise a type that combines the aliasing of t1 and t2 is returned. Uniqueness is unified with uf. Assumes sizes already match, and always picks the size of the leftmost type.

subtypeOf :: TypeBase () () -> TypeBase () () -> Bool

x `subtypeOf` y is true if x is a subtype of y (or equal to y), meaning x is valid whenever y is. Ignores sizes. Mostly used for checking uniqueness.

subuniqueOf :: Uniqueness -> Uniqueness -> Bool

x subuniqueOf y is true if x is not less unique than y.

checkForDuplicateNames :: MonadTypeChecker m => [UncheckedPat] -> m ()

Check for duplication of names inside a pattern group. Produces a description of all names used in the pattern group.

checkTypeParams :: MonadTypeChecker m => [TypeParamBase Name] -> ([TypeParamBase VName] -> m a) -> m a

checkTypeParams ps m checks the type parameters ps, then invokes the continuation m with the checked parameters, while extending the monadic name map with ps.

typeParamToArg :: TypeParam -> StructTypeArg

Construct a type argument corresponding to a type parameter.

data Subst t

A type substitution may be a substitution or a yet-unknown substitution (but which is certainly an overloaded primitive type!). The latter is used to remove aliases from types that are yet-unknown but that we know cannot carry aliases (see issue #682).

Constructors

Subst [TypeParam] t

PrimSubst

SizeSubst (DimDecl VName)

Instances

Functor Subst

Defined in Language.Futhark.TypeChecker.Types

Methods

fmap :: (a -> b) -> Subst a -> Subst b

(<$) :: a -> Subst b -> Subst a

Show t => Show (Subst t)

Defined in Language.Futhark.TypeChecker.Types

Methods

showsPrec :: Int -> Subst t -> ShowS

show :: Subst t -> String

showList :: [Subst t] -> ShowS

Pretty t => Pretty (Subst t)

Defined in Language.Futhark.TypeChecker.Types

Methods

ppr :: Subst t -> Doc

pprPrec :: Int -> Subst t -> Doc

pprList :: [Subst t] -> Doc

substFromAbbr :: TypeBinding -> Subst StructRetType

Create a type substitution corresponding to a type binding.

type TypeSubs = VName -> Maybe (Subst StructRetType)

Substitutions to apply in a type.

class Substitutable a where

Class of types which allow for substitution of types with no annotations for type variable names.

Methods

applySubst :: TypeSubs -> a -> a

Instances

Substitutable Pat

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> Pat -> Pat

Substitutable d => Substitutable (ShapeDecl d)

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> ShapeDecl d -> ShapeDecl d

Substitutable (DimDecl VName)

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> DimDecl VName -> DimDecl VName

Substitutable (TypeBase (DimDecl VName) ())

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> TypeBase (DimDecl VName) () -> TypeBase (DimDecl VName) ()

Substitutable (TypeBase (DimDecl VName) Aliasing)

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> TypeBase (DimDecl VName) Aliasing -> TypeBase (DimDecl VName) Aliasing

Substitutable (RetTypeBase (DimDecl VName) ())

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> RetTypeBase (DimDecl VName) () -> RetTypeBase (DimDecl VName) ()

Substitutable (RetTypeBase (DimDecl VName) Aliasing)

Defined in Language.Futhark.TypeChecker.Types

Methods

applySubst :: TypeSubs -> RetTypeBase (DimDecl VName) Aliasing -> RetTypeBase (DimDecl VName) Aliasing

substTypesAny :: Monoid as => (VName -> Maybe (Subst (RetTypeBase (DimDecl VName) as))) -> TypeBase (DimDecl VName) as -> TypeBase (DimDecl VName) as

Perform substitutions, from type names to types, on a type. Works regardless of what shape and uniqueness information is attached to the type.