Safe Haskell	Safe-Inferred

DDC.Core.Exp.Annot

Contents

Expressions
Witnesses
Data Constructors
Witness Constructors

Description

Core language AST that includes an annotation on every node of an expression.

This is the default representation for Disciple Core, and should be preferred over the Simple version of the AST in most cases.

Local transformations on this AST should propagate the annotations in a way that would make sense if they were source position identifiers that tracked the provenance of each code snippet. If the specific annotations attached to the AST would not make sense after such a transformation, then the client should erase them to () beforehand using the reannotate transform.
Global transformations that drastically change the provenance of code snippets should accept an AST with an arbitrary annotation type, but produce one with the annotations set to ().

Synopsis

Documentation

module DDC.Type.Exp

Expressions

data Exp a n Source

Well-typed expressions have types of kind Data.

Constructors

XVar !a !(Bound n)	Value variable or primitive operation.
XCon !a !(DaCon n)	Data constructor or literal.
XLAM !a !(Bind n) !(Exp a n)	Type abstraction (level-1).
XLam !a !(Bind n) !(Exp a n)	Value and Witness abstraction (level-0).
XApp !a !(Exp a n) !(Exp a n)	Application.
XLet !a !(Lets a n) !(Exp a n)	Possibly recursive bindings.
XCase !a !(Exp a n) ![Alt a n]	Case branching.
XCast !a !(Cast a n) !(Exp a n)	Type cast.
XType !a !(Type n)	Type can appear as the argument of an application.
XWitness !a !(Witness a n)	Witness can appear as the argument of an application.

Instances

Reannotate Exp
Complies Exp
SubstituteWX Exp
SubstituteXX Exp
Annotate Exp Exp
Deannotate Exp Exp
SpreadX (Exp a)
BindStruct (Exp a)
SupportX (Exp a)
SubstituteTX (Exp a)
MapBoundX (Exp a) n
Ord n => MapBoundT (Exp a) n
(Eq a, Eq n) => Eq (Exp a n)
(Show a, Show n) => Show (Exp a n)
(Pretty n, Eq n) => Pretty (Exp a n)
(NFData a, NFData n) => NFData (Exp a n)

data Lets a n Source

Possibly recursive bindings.

Constructors

LLet !(Bind n) !(Exp a n)	Non-recursive expression binding.
LRec ![(Bind n, Exp a n)]	Recursive binding of lambda abstractions.
LPrivate ![Bind n] !(Maybe (Type n)) ![Bind n]	Bind a private region variable, and witnesses to its properties.
LWithRegion !(Bound n)	Holds a region handle during evaluation.

Instances

Reannotate Lets
Annotate Lets Lets
Deannotate Lets Lets
SpreadX (Lets a)
SupportX (Lets a)
(Eq a, Eq n) => Eq (Lets a n)
(Show a, Show n) => Show (Lets a n)
(Pretty n, Eq n) => Pretty (Lets a n)
(NFData a, NFData n) => NFData (Lets a n)

data Alt a n Source

Case alternatives.

Constructors

AAlt !(Pat n) !(Exp a n)

Instances

Reannotate Alt
Complies Alt
SubstituteWX Alt
SubstituteXX Alt
Annotate Alt Alt
Deannotate Alt Alt
SpreadX (Alt a)
BindStruct (Alt a)
SupportX (Alt a)
SubstituteTX (Alt a)
MapBoundX (Alt a) n
Ord n => MapBoundT (Alt a) n
(Eq a, Eq n) => Eq (Alt a n)
(Show a, Show n) => Show (Alt a n)
(Pretty n, Eq n) => Pretty (Alt a n)
(NFData a, NFData n) => NFData (Alt a n)

data Pat n Source

Pattern matching.

Constructors

PDefault	The default pattern always succeeds.
PData !(DaCon n) ![Bind n]	Match a data constructor and bind its arguments.

Instances

SpreadX Pat
Eq n => Eq (Pat n)
Show n => Show (Pat n)
(Pretty n, Eq n) => Pretty (Pat n)
NFData n => NFData (Pat n)

data Cast a n Source

Type casts.

Constructors

CastWeakenEffect !(Effect n)	Weaken the effect of an expression. The given effect is added to the effect of the body.
CastWeakenClosure ![Exp a n]	Weaken the closure of an expression. The closures of these expressions are added to the closure of the body.
CastPurify !(Witness a n)	Purify the effect (action) of an expression.
CastForget !(Witness a n)	Forget about the closure (sharing) of an expression.
CastBox	Box up a computation, capturing its effects in the S computation type.
CastRun	Run a computation, releasing its effects into the environment.

Instances

Reannotate Cast
SubstituteWX Cast
SubstituteXX Cast
Annotate Cast Cast
Deannotate Cast Cast
SpreadX (Cast a)
BindStruct (Cast a)
SupportX (Cast a)
SubstituteTX (Cast a)
MapBoundX (Cast a) n
Ord n => MapBoundT (Cast a) n
(Eq a, Eq n) => Eq (Cast a n)
(Show a, Show n) => Show (Cast a n)
(Pretty n, Eq n) => Pretty (Cast a n)
(NFData a, NFData n) => NFData (Cast a n)

Witnesses

data Witness a n Source

When a witness exists in the program it guarantees that a certain property of the program is true.

Constructors

WVar a !(Bound n)	Witness variable.
WCon a !(WiCon n)	Witness constructor.
WApp a !(Witness a n) !(Witness a n)	Witness application.
WJoin a !(Witness a n) !(Witness a n)	Joining of witnesses.
WType a !(Type n)	Type can appear as the argument of an application.

Instances

Reannotate Witness
SubstituteWX Witness
Annotate Witness Witness
Deannotate Witness Witness
Rename (Witness a)
SpreadX (Witness a)
BindStruct (Witness a)
SupportX (Witness a)
SubstituteTX (Witness a)
MapBoundX (Witness a) n
Ord n => MapBoundT (Witness a) n
(Eq a, Eq n) => Eq (Witness a n)
(Show a, Show n) => Show (Witness a n)
(Pretty n, Eq n) => Pretty (Witness a n)
(NFData a, NFData n) => NFData (Witness a n)

Data Constructors

data DaCon n Source

Data constructors.

Constructors

DaConUnit	Baked in unit data constructor.
DaConPrim	Primitive data constructor used for literals and baked-in constructors. The type of the constructor needs to be attached to handle the case where there are too many constructors in the data type to list, like for Int literals. In this case we determine what data type it belongs to from the attached type of the data constructor.
Fields daConName :: !n Name of the data constructor. Name of the data constructor. daConType :: !(Type n) Type of the data constructor.
DaConBound	Data constructor that has a data type declaration.
Fields daConName :: !n Name of the data constructor. Name of the data constructor.

Instances

SpreadX DaCon
Eq n => Eq (DaCon n)
Show n => Show (DaCon n)
(Pretty n, Eq n) => Pretty (DaCon n)
NFData n => NFData (DaCon n)

Witness Constructors

data WiCon n Source

Witness constructors.

Constructors

WiConBuiltin !WbCon	Witness constructors baked into the language.
WiConBound !(Bound n) !(Type n)	Witness constructors defined in the environment. In the interpreter we use this to hold runtime capabilities. The attached type must be closed.

Instances

SpreadX WiCon
Eq n => Eq (WiCon n)
Show n => Show (WiCon n)
(Pretty n, Eq n) => Pretty (WiCon n)
NFData n => NFData (WiCon n)

data WbCon Source

Built-in witness constructors.

These are used to convert a runtime capability into a witness that the corresponding property is true.

Constructors

WbConPure	(axiom) The pure effect is pure. pure :: Pure !0
WbConEmpty	(axiom) The empty closure is empty. empty :: Empty $0
WbConUse	Convert a capability guaranteeing that a region is in the global heap, into a witness that a closure using this region is empty. This lets us rely on the garbage collector to reclaim objects in the region. It is needed when we suspend the evaluation of expressions that have a region in their closure, because the type of the returned thunk may not reveal that it references objects in that region. use :: [r : %]. Global r => Empty (Use r)
WbConRead	Convert a capability guaranteeing the constancy of a region, into a witness that a read from that region is pure. This lets us suspend applications that read constant objects, because it doesn't matter if the read is delayed, we'll always get the same result. read :: [r : %]. Const r => Pure (Read r)
WbConAlloc	Convert a capability guaranteeing the constancy of a region, into a witness that allocation into that region is pure. This lets us increase the sharing of constant objects, because we can't tell constant objects of the same value apart. alloc :: [r : %]. Const r => Pure (Alloc r)

Instances

Eq WbCon
Show WbCon
Pretty WbCon
NFData WbCon