Language.Futhark.Prop

This module provides various simple ways to query and manipulate fundamental Futhark terms, such as types and values. The intent is to keep Futhark.Language.Syntax simple, and put whatever embellishments we need here.

Various

data Intrinsic

The nature of something predefined. For functions, these can either be monomorphic or overloaded. An overloaded builtin is a list valid types it can be instantiated with, to the parameter and result type, with Nothing representing the overloaded parameter type.

Constructors

IntrinsicMonoFun [PrimType] PrimType

IntrinsicOverloadedFun [PrimType] [Maybe PrimType] (Maybe PrimType)

IntrinsicPolyFun [TypeParamBase VName] [ParamType] (RetTypeBase Size Uniqueness)

IntrinsicType Liftedness [TypeParamBase VName] StructType

IntrinsicEquality

intrinsics :: Map VName Intrinsic

A map of all built-ins.

intrinsicVar :: Name -> VName

Find the VName corresponding to a builtin. Crashes if that name cannot be found.

isBuiltin :: FilePath -> Bool

Is this include part of the built-in prelude?

isBuiltinLoc :: Located a => a -> Bool

Is the position of this thing builtin as per isBuiltin? Things without location are considered not built-in.

maxIntrinsicTag :: Int

The largest tag used by an intrinsic - this can be used to determine whether a VName refers to an intrinsic or a user-defined name.

namesToPrimTypes :: Map Name PrimType

Names of primitive types to types. This is only valid if no shadowing is going on, but useful for tools.

qualName :: v -> QualName v

Create a name with no qualifiers from a name.

qualify :: v -> QualName v -> QualName v

Add another qualifier (at the head) to a qualified name.

primValueType :: PrimValue -> PrimType

The type of a basic value.

leadingOperator :: Name -> BinOp

Given an operator name, return the operator that determines its syntactical properties.

progImports :: ProgBase f vn -> [(String, Loc)]

The modules imported by a Futhark program.

decImports :: DecBase f vn -> [(String, Loc)]

The modules imported by a single declaration.

progModuleTypes :: ProgBase Info VName -> Set VName

The set of module types used in any exported (non-local) declaration.

identifierReference :: String -> Maybe ((String, String, Maybe FilePath), String)

Extract a leading ((name, namespace, file), remainder) from a documentation comment string. These are formatted as `name`@namespace[@file]. Let us hope that this pattern does not occur anywhere else.

prettyStacktrace :: Int -> [Text] -> Text

Given a list of strings representing entries in the stack trace and the index of the frame to highlight, produce a final newline-terminated string for showing to the user. This string should also be preceded by a newline. The most recent stack frame must come first in the list.

progHoles :: ProgBase Info VName -> [(Loc, StructType)]

Find instances of typed holes in the program.

defaultEntryPoint :: Name

The name of the default program entry point (main).

paramName :: PName -> Maybe VName

The name, if any.

anySize :: Size

A special expression representing no known size. When present in a type, each instance represents a distinct size. The type checker should _never_ produce these - they are a (hopefully temporary) thing introduced by defunctorisation and monomorphisation. They represent a flaw in our implementation. When they occur in a return type, they can be replaced with freshly created existential sizes. When they occur in parameter types, they can be replaced with size parameters.

Queries on expressions

typeOf :: ExpBase Info VName -> StructType

The type of an Futhark term. The aliasing will refer to itself, if the term is a non-tuple-typed variable.

valBindTypeScheme :: ValBindBase Info VName -> ([TypeParamBase VName], StructType)

The type scheme of a value binding, comprising the type parameters and the actual type.

valBindBound :: ValBindBase Info VName -> [VName]

The names that are brought into scope by this value binding (not including its own parameter names, but including any existential sizes).

funType :: [Pat ParamType] -> ResRetType -> StructType

The type of a function with the given parameters and return type.

stripExp :: Exp -> Maybe Exp

Strip semantically irrelevant stuff from the top level of expression. This is used to provide a slightly fuzzy notion of expression equality.

Ideally we'd implement unification on a simpler representation that simply didn't allow us.

similarExps :: Exp -> Exp -> Maybe [(Exp, Exp)]

If these two expressions are structurally similar at top level as sizes, produce their subexpressions (which are not necessarily similar, but you can check for that!). This is the machinery underlying expresssion unification. We assume that the expressions have the same type.

Queries on patterns and params

patIdents :: PatBase f vn t -> [IdentBase f vn t]

The set of identifiers bound in a pattern.

patNames :: Pat t -> [VName]

The set of names bound in a pattern.

patternMap :: Pat t -> [(VName, t)]

Each name bound in a pattern alongside its type.

patternType :: Pat (TypeBase d u) -> TypeBase d u

The type of values bound by the pattern.

patternStructType :: Pat (TypeBase Size u) -> StructType

The type matched by the pattern, including shape declarations if present.

patternParam :: Pat ParamType -> (PName, Diet, StructType)

When viewed as a function parameter, does this pattern correspond to a named parameter of some type?

patternOrderZero :: Pat (TypeBase d u) -> Bool

patternOrderZero pat is True if all of the types in the given pattern have order 0.

Queries on types

uniqueness :: TypeBase shape Uniqueness -> Uniqueness

Return the uniqueness of a type.

unique :: TypeBase shape Uniqueness -> Bool

unique t is True if the type of the argument is unique.

diet :: TypeBase shape Diet -> Diet

diet t returns a description of how a function parameter of type t consumes its argument.

arrayRank :: TypeBase d u -> Int

Return the dimensionality of a type. For non-arrays, this is zero. For a one-dimensional array it is one, for a two-dimensional it is two, and so forth.

arrayShape :: TypeBase dim as -> Shape dim

Return the shape of a type - for non-arrays, this is mempty.

orderZero :: TypeBase dim as -> Bool

orderZero t is True if the argument type has order 0, i.e., it is not a function type, does not contain a function type as a subcomponent, and may not be instantiated with a function type.

unfoldFunType :: TypeBase dim as -> ([TypeBase dim Diet], TypeBase dim NoUniqueness)

Extract the parameter types and return type from a type. If the type is not an arrow type, the list of parameter types is empty.

foldFunType :: [ParamType] -> ResRetType -> StructType

foldFunType ts ret creates a function type (Arrow) that takes ts as parameters and returns ret.

typeVars :: TypeBase dim as -> Set VName

The type names mentioned in a type.

isAccType :: TypeBase d u -> Maybe (TypeBase d NoUniqueness)

If this type corresponds to the builtin "acc" type, return the type of the underlying array.

Operations on types

peelArray :: Int -> TypeBase dim u -> Maybe (TypeBase dim u)

peelArray n t returns the type resulting from peeling the first n array dimensions from t. Returns Nothing if t has less than n dimensions.

stripArray :: Int -> TypeBase dim as -> TypeBase dim as

stripArray n t removes the n outermost layers of the array. Essentially, it is the type of indexing an array of type t with n indexes.

arrayOf :: Shape dim -> TypeBase dim NoUniqueness -> TypeBase dim NoUniqueness

arrayOf u s t constructs an array type. The convenience compared to using the Array constructor directly is that t can itself be an array. If t is an n-dimensional array, and s is a list of length n, the resulting type is of an n+m dimensions.

arrayOfWithAliases :: u -> Shape dim -> TypeBase dim u' -> TypeBase dim u

Like arrayOf, but you can pass in uniqueness info of the resulting array.

toStructural :: TypeBase dim as -> TypeBase () ()

Convert any type to one that has rank information, no alias information, and no embedded names.

toStruct :: TypeBase dim u -> TypeBase dim NoUniqueness

Remove uniquenss information from a type.

toRes :: Uniqueness -> TypeBase Size u -> ResType

Convert to ResType

toParam :: Diet -> TypeBase Size u -> ParamType

Uses Observe.

resToParam :: ResType -> ParamType

Preserves relation between Diet and Uniqueness.

paramToRes :: ParamType -> ResType

Preserves relation between Diet and Uniqueness.

toResRet :: Uniqueness -> RetTypeBase Size u -> ResRetType

Convert to ResRetType

setUniqueness :: TypeBase dim u1 -> u2 -> TypeBase dim u2

Set the uniqueness attribute of a type. If the type is a record or sum type, the uniqueness of its components will be modified.

noSizes :: TypeBase Size as -> TypeBase () as

Change the shape of a type to be just the rank.

traverseDims :: forall f fdim tdim als. Applicative f => (Set VName -> DimPos -> fdim -> f tdim) -> TypeBase fdim als -> f (TypeBase tdim als)

Perform a traversal (possibly including replacement) on sizes that are parameters in a function type, but also including the type immediately passed to the function. Also passes along a set of the parameter names inside the type that have come in scope at the occurrence of the dimension.

data DimPos

Where does this dimension occur?

Constructors

PosImmediate

Immediately in the argument to traverseDims.

PosParam

In a function parameter type.

PosReturn

In a function return type.

Instances

Show DimPos

Defined in Language.Futhark.Prop

Methods

showsPrec :: Int -> DimPos -> ShowS

show :: DimPos -> String

showList :: [DimPos] -> ShowS

Eq DimPos

Defined in Language.Futhark.Prop

Methods

(==) :: DimPos -> DimPos -> Bool

(/=) :: DimPos -> DimPos -> Bool

Ord DimPos

Defined in Language.Futhark.Prop

Methods

compare :: DimPos -> DimPos -> Ordering

(<) :: DimPos -> DimPos -> Bool

(<=) :: DimPos -> DimPos -> Bool

(>) :: DimPos -> DimPos -> Bool

(>=) :: DimPos -> DimPos -> Bool

max :: DimPos -> DimPos -> DimPos

min :: DimPos -> DimPos -> DimPos

tupleRecord :: [TypeBase dim as] -> ScalarTypeBase dim as

Create a record type corresponding to a tuple with the given element types.

isTupleRecord :: TypeBase dim as -> Maybe [TypeBase dim as]

Does this type corespond to a tuple? If so, return the elements of that tuple.

areTupleFields :: Map Name a -> Maybe [a]

Does this record map correspond to a tuple?

tupleFields :: [a] -> Map Name a

Construct a record map corresponding to a tuple.

tupleFieldNames :: [Name]

Increasing field names for a tuple (starts at 0).

sortFields :: Map Name a -> [(Name, a)]

Sort fields by their name; taking care to sort numeric fields by their numeric value. This ensures that tuples and tuple-like records match.

sortConstrs :: Map Name a -> [(Name, a)]

Sort the constructors of a sum type in some well-defined (but not otherwise significant) manner.

isTypeParam :: TypeParamBase vn -> Bool

Is this a TypeParamType?

isSizeParam :: TypeParamBase vn -> Bool

Is this a TypeParamDim?

matchDims :: forall as m d1 d2. (Monoid as, Monad m) => ([VName] -> d1 -> d2 -> m d1) -> TypeBase d1 as -> TypeBase d2 as -> m (TypeBase d1 as)

Match the dimensions of otherwise assumed-equal types. The combining function is also passed the names bound within the type (from named parameters or return types).

Un-typechecked ASTs

type UncheckedType = TypeBase (Shape Name) ()

A type with no aliasing information but shape annotations.

type UncheckedTypeExp = TypeExp UncheckedExp Name

An unchecked type expression.

type UncheckedIdent = IdentBase NoInfo Name

An identifier with no type annotations.

type UncheckedDimIndex = DimIndexBase NoInfo Name

An index with no type annotations.

type UncheckedSlice = SliceBase NoInfo Name

A slice with no type annotations.

type UncheckedExp = ExpBase NoInfo Name

An expression with no type annotations.

type UncheckedModExp = ModExpBase NoInfo Name

A module expression with no type annotations.

type UncheckedModTypeExp = ModTypeExpBase NoInfo Name

A module type expression with no type annotations.

type UncheckedTypeParam = TypeParamBase Name

A type parameter with no type annotations.

type UncheckedPat = PatBase NoInfo Name

A pattern with no type annotations.

type UncheckedValBind = ValBindBase NoInfo Name

A function declaration with no type annotations.

type UncheckedTypeBind = TypeBindBase NoInfo Name

A type binding with no type annotations.

type UncheckedModTypeBind = ModTypeBindBase NoInfo Name

A module type binding with no type annotations.

type UncheckedModBind = ModBindBase NoInfo Name

A module binding with no type annotations.

type UncheckedDec = DecBase NoInfo Name

A declaration with no type annotations.

type UncheckedSpec = SpecBase NoInfo Name

A spec with no type annotations.

type UncheckedProg = ProgBase NoInfo Name

A Futhark program with no type annotations.

type UncheckedCase = CaseBase NoInfo Name

A case (of a match expression) with no type annotations.

Type-checked ASTs

type Ident = IdentBase Info VName

An identifier with type- and aliasing information.

type DimIndex = DimIndexBase Info VName

An index with type information.

type Slice = SliceBase Info VName

A slice with type information.

type AppExp = AppExpBase Info VName

An application expression with type information.

type Exp = ExpBase Info VName

An expression with type information.

type Pat = PatBase Info VName

A pattern with type information.

type ModExp = ModExpBase Info VName

A type-checked module expression.

type ModParam = ModParamBase Info VName

A type-checked module parameter.

type ModTypeExp = ModTypeExpBase Info VName

A type-checked module type expression.

type ModBind = ModBindBase Info VName

A type-checked module binding.

type ModTypeBind = ModTypeBindBase Info VName

A type-checked module type binding.

type ValBind = ValBindBase Info VName

An constant declaration with type information.

type Dec = DecBase Info VName

A type-checked declaration.

type Spec = SpecBase Info VName

A type-checked specification.

type Prog = ProgBase Info VName

An Futhark program with type information.

type TypeBind = TypeBindBase Info VName

A type binding with type information.

type StructTypeArg = TypeArg Size

A known type arg with shape annotations.

type ScalarType = ScalarTypeBase ()

A known scalar type with no shape annotations.

type TypeParam = TypeParamBase VName

A type-checked type parameter.

type Case = CaseBase Info VName

A type-checked case (of a match expression).