Safe Haskell	Safe-Inferred
Language	Haskell2010

UntypedPlutusCore.Purity

Synopsis

isPure :: ToBuiltinMeaning uni fun => BuiltinSemanticsVariant fun -> Term name uni fun a -> Bool
isWorkFree :: ToBuiltinMeaning uni fun => BuiltinSemanticsVariant fun -> Term name uni fun a -> Bool
data EvalOrder name uni fun a
unEvalOrder :: EvalOrder name uni fun a -> [EvalTerm name uni fun a]
data EvalTerm name uni fun a
- = Unknown
- | EvalTerm Purity WorkFreedom (Term name uni fun a)
data Purity
- = MaybeImpure
- | Pure
data WorkFreedom
- = MaybeWork
- | WorkFree
termEvaluationOrder :: forall name uni fun a. ToBuiltinMeaning uni fun => BuiltinSemanticsVariant fun -> Term name uni fun a -> EvalOrder name uni fun a

Documentation

isPure :: ToBuiltinMeaning uni fun => BuiltinSemanticsVariant fun -> Term name uni fun a -> Bool Source #

Will evaluating this term have side effects (looping or error)? This is slightly wider than the definition of a value, as it includes applications that are known to be pure, as well as things that can't be returned from the machine (as they'd be ill-scoped).

isWorkFree :: ToBuiltinMeaning uni fun => BuiltinSemanticsVariant fun -> Term name uni fun a -> Bool Source #

Is the given term 'work-free'?

Note: The definition of 'work-free' is a little unclear, but the idea is that evaluating this term should do very a trivial amount of work.

data EvalOrder name uni fun a Source #

The order in which terms get evaluated, along with their purities.

Instances

Instances details

PrettyBy config (Term name uni fun a) => PrettyBy config (EvalOrder name uni fun a) Source #
Instance details Defined in UntypedPlutusCore.Purity Methods prettyBy :: config -> EvalOrder name uni fun a -> Doc ann # prettyListBy :: config -> [EvalOrder name uni fun a] -> Doc ann #
Monoid (EvalOrder name uni fun a) Source #
Instance details Defined in UntypedPlutusCore.Purity Methods mempty :: EvalOrder name uni fun a Source # mappend :: EvalOrder name uni fun a -> EvalOrder name uni fun a -> EvalOrder name uni fun a Source # mconcat :: [EvalOrder name uni fun a] -> EvalOrder name uni fun a Source #
Semigroup (EvalOrder name uni fun a) Source #
Instance details Defined in UntypedPlutusCore.Purity Methods (<>) :: EvalOrder name uni fun a -> EvalOrder name uni fun a -> EvalOrder name uni fun a Source # sconcat :: NonEmpty (EvalOrder name uni fun a) -> EvalOrder name uni fun a Source # stimes :: Integral b => b -> EvalOrder name uni fun a -> EvalOrder name uni fun a Source #

unEvalOrder :: EvalOrder name uni fun a -> [EvalTerm name uni fun a] Source #

Get the evaluation order as a list of EvalTerms. Either terminates in a single Unknown, which means that we got to a point where evaluation continues but we don't know where; or terminates normally, in which case we actually got to the end of the evaluation order for the term.

data EvalTerm name uni fun a Source #

Either the "next" term to be evaluated, along with its Purity and WorkFreedom, or we don't know what comes next.

Constructors

Unknown
EvalTerm Purity WorkFreedom (Term name uni fun a)

Instances

Instances details

PrettyBy config (Term name uni fun a) => PrettyBy config (EvalTerm name uni fun a) Source #
Instance details Defined in UntypedPlutusCore.Purity Methods prettyBy :: config -> EvalTerm name uni fun a -> Doc ann # prettyListBy :: config -> [EvalTerm name uni fun a] -> Doc ann #
(Show name, Everywhere uni Show, Show fun, Show a, GShow uni, Closed uni) => Show (EvalTerm name uni fun a) Source #
Instance details Defined in UntypedPlutusCore.Purity Methods showsPrec :: Int -> EvalTerm name uni fun a -> ShowS Source # show :: EvalTerm name uni fun a -> String Source # showList :: [EvalTerm name uni fun a] -> ShowS Source #
Eq (Term name uni fun a) => Eq (EvalTerm name uni fun a) Source #
Instance details Defined in UntypedPlutusCore.Purity Methods (==) :: EvalTerm name uni fun a -> EvalTerm name uni fun a -> Bool Source # (/=) :: EvalTerm name uni fun a -> EvalTerm name uni fun a -> Bool Source #

data Purity Source #

Is this pure? Either yes, or maybe not.

Constructors

MaybeImpure
Pure

Instances

Instances details

Show Purity Source #
Instance details Defined in UntypedPlutusCore.Purity Methods showsPrec :: Int -> Purity -> ShowS Source # show :: Purity -> String Source # showList :: [Purity] -> ShowS Source #
Eq Purity Source #
Instance details Defined in UntypedPlutusCore.Purity Methods (==) :: Purity -> Purity -> Bool Source # (/=) :: Purity -> Purity -> Bool Source #
Pretty Purity Source #
Instance details Defined in UntypedPlutusCore.Purity Methods pretty :: Purity -> Doc ann # prettyList :: [Purity] -> Doc ann #

data WorkFreedom Source #

Is this term essentially work-free? Either yes, or maybe not.

Constructors

MaybeWork
WorkFree

Instances

Instances details

Show WorkFreedom Source #
Instance details Defined in UntypedPlutusCore.Purity Methods showsPrec :: Int -> WorkFreedom -> ShowS Source # show :: WorkFreedom -> String Source # showList :: [WorkFreedom] -> ShowS Source #
Eq WorkFreedom Source #
Instance details Defined in UntypedPlutusCore.Purity Methods (==) :: WorkFreedom -> WorkFreedom -> Bool Source # (/=) :: WorkFreedom -> WorkFreedom -> Bool Source #
Pretty WorkFreedom Source #
Instance details Defined in UntypedPlutusCore.Purity Methods pretty :: WorkFreedom -> Doc ann # prettyList :: [WorkFreedom] -> Doc ann #

termEvaluationOrder :: forall name uni fun a. ToBuiltinMeaning uni fun => BuiltinSemanticsVariant fun -> Term name uni fun a -> EvalOrder name uni fun a Source #

Given a term, return the order in which it and its sub-terms will be evaluated.

This aims to be a sound under-approximation: if we don't know, we just say Unknown. Typically there will be a sequence of terms that we do know, which will terminate in Unknown once we do something like call a function.

This makes some assumptions about the evaluator, in particular about the order in which we evaluate sub-terms, but these match the current evaluator and we are not planning on changing it.