Symantic.Typed.ObserveSharing

Class Letable

class Letable letName repr where

This class is not for end-users like usual symantic operators, here shareable and ref are introduced by observeSharing.

Minimal complete definition

Nothing

Methods

ref :: Bool -> letName -> repr a

(ref isRec letName) is a reference to (letName). (isRec) is True iif. this reference is recursive, ie. is reachable within its shareable definition.

default ref :: FromDerived (Letable letName) repr => Bool -> letName -> repr a

shareable :: letName -> repr a -> repr a

(shareable letName x) let-binds (letName) to be equal to (x).

default shareable :: FromDerived1 (Letable letName) repr => letName -> repr a -> repr a

Instances

(Letable letName repr, Eq letName, Hashable letName, Show letName) => Letable letName (FinalizeSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

ref :: Bool -> letName -> FinalizeSharing letName repr a

shareable :: letName -> FinalizeSharing letName repr a -> FinalizeSharing letName repr a

Letable letName (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

ref :: Bool -> letName -> ObserveSharing letName repr a

shareable :: letName -> ObserveSharing letName repr a -> ObserveSharing letName repr a

Class MakeLetName

class MakeLetName letName where

Methods

makeLetName :: SharingName -> IO letName

Type ShowLetName

class ShowLetName (showName :: Bool) letName where

Useful on golden unit tests because StableName change often when changing unrelated source code or even changing basic GHC or executable flags.

Methods

showLetName :: letName -> String

Instances

ShowLetName 'False letName

Always return "hidden",

Defined in Symantic.Typed.ObserveSharing

Methods

showLetName :: letName -> String

Show letName => ShowLetName 'True letName

Like Show.

Defined in Symantic.Typed.ObserveSharing

Methods

showLetName :: letName -> String

Type SharingName

data SharingName

Note that the observable sharing enabled by StableName is not perfect as it will not observe all the sharing explicitely done.

Note also that the observed sharing could be different between ghc and ghci.

Constructors

forall a. SharingName (StableName a)

Instances

Eq SharingName

Defined in Symantic.Typed.ObserveSharing

Methods

(==) :: SharingName -> SharingName -> Bool

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

Hashable SharingName

Defined in Symantic.Typed.ObserveSharing

Methods

hashWithSalt :: Int -> SharingName -> Int

hash :: SharingName -> Int

makeSharingName :: a -> SharingName

(makeSharingName x) is like (makeStableName x) but it also forces evaluation of (x) to ensure that the StableName is correct first time, which avoids to produce a tree bigger than needed.

Note that this function uses unsafePerformIO instead of returning in IO, this is apparently required to avoid infinite loops due to unstable StableName in compiled code, and sometimes also in ghci.

Note that maybe pseq should be used here.

Type ObserveSharing

newtype ObserveSharing letName repr a

Constructors

ObserveSharing

Fields

• unObserveSharing :: ReaderT (HashSet SharingName) (State (ObserveSharingState letName)) (FinalizeSharing letName repr a)

Instances

Letsable letName (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

lets :: LetBindings letName (ObserveSharing letName repr) -> ObserveSharing letName repr a -> ObserveSharing letName repr a

Letable letName (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

ref :: Bool -> letName -> ObserveSharing letName repr a

shareable :: letName -> ObserveSharing letName repr a -> ObserveSharing letName repr a

(Letable letName repr, MakeLetName letName, Eq letName, Hashable letName, Show letName) => LiftDerived3 (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived3 :: (Derived (ObserveSharing letName repr) a -> Derived (ObserveSharing letName repr) b -> Derived (ObserveSharing letName repr) c -> Derived (ObserveSharing letName repr) d) -> ObserveSharing letName repr a -> ObserveSharing letName repr b -> ObserveSharing letName repr c -> ObserveSharing letName repr d

(Letable letName repr, MakeLetName letName, Eq letName, Hashable letName, Show letName) => LiftDerived2 (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived2 :: (Derived (ObserveSharing letName repr) a -> Derived (ObserveSharing letName repr) b -> Derived (ObserveSharing letName repr) c) -> ObserveSharing letName repr a -> ObserveSharing letName repr b -> ObserveSharing letName repr c

(Letable letName repr, MakeLetName letName, Eq letName, Hashable letName, Show letName) => LiftDerived1 (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived1 :: (Derived (ObserveSharing letName repr) a -> Derived (ObserveSharing letName repr) b) -> ObserveSharing letName repr a -> ObserveSharing letName repr b

(Letable letName repr, MakeLetName letName, Eq letName, Hashable letName, Show letName) => LiftDerived (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived :: Derived (ObserveSharing letName repr) a -> ObserveSharing letName repr a

type Derived (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

type Derived (ObserveSharing letName repr) = FinalizeSharing letName repr

observeSharing :: Eq letName => Hashable letName => Show letName => ObserveSharing letName repr a -> WithSharing letName repr a

Interpreter detecting some (Haskell embedded) let definitions used at least once and/or recursively, in order to replace them with the shareable and ref combinators. See Type-safe observable sharing in Haskell

Beware not to apply observeSharing more than once on the same term otherwise some shareable introduced by the first call would be removed by the second call.

Type SomeLet

data SomeLet repr

Constructors

forall a. SomeLet (repr a)

Type WithSharing

type WithSharing letName repr a = (repr a, HashMap letName (SomeLet repr))

Type ObserveSharingState

data ObserveSharingState letName

Constructors

ObserveSharingState

Fields

• oss_refs :: HashMap SharingName (letName, Int)
• oss_recs :: HashSet SharingName

  TODO: unused so far, will it be useful somewhere at a later stage?

observeSharingNode :: Eq letName => Hashable letName => Show letName => Letable letName repr => MakeLetName letName => ObserveSharing letName repr a -> ObserveSharing letName repr a

Type FinalizeSharing

newtype FinalizeSharing letName repr a

Remove shareable when non-recursive or unused or replace it by ref, moving shareables to the top.

Constructors

FinalizeSharing

Fields

• unFinalizeSharing :: ReaderT (HashSet letName) (Writer (LetBindings letName repr)) (repr a)

Instances

(Letable letName repr, Eq letName, Hashable letName, Show letName) => Letable letName (FinalizeSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

ref :: Bool -> letName -> FinalizeSharing letName repr a

shareable :: letName -> FinalizeSharing letName repr a -> FinalizeSharing letName repr a

(Eq letName, Hashable letName) => LiftDerived3 (FinalizeSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived3 :: (Derived (FinalizeSharing letName repr) a -> Derived (FinalizeSharing letName repr) b -> Derived (FinalizeSharing letName repr) c -> Derived (FinalizeSharing letName repr) d) -> FinalizeSharing letName repr a -> FinalizeSharing letName repr b -> FinalizeSharing letName repr c -> FinalizeSharing letName repr d

(Eq letName, Hashable letName) => LiftDerived2 (FinalizeSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived2 :: (Derived (FinalizeSharing letName repr) a -> Derived (FinalizeSharing letName repr) b -> Derived (FinalizeSharing letName repr) c) -> FinalizeSharing letName repr a -> FinalizeSharing letName repr b -> FinalizeSharing letName repr c

(Eq letName, Hashable letName) => LiftDerived1 (FinalizeSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived1 :: (Derived (FinalizeSharing letName repr) a -> Derived (FinalizeSharing letName repr) b) -> FinalizeSharing letName repr a -> FinalizeSharing letName repr b

(Eq letName, Hashable letName) => LiftDerived (FinalizeSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

liftDerived :: Derived (FinalizeSharing letName repr) a -> FinalizeSharing letName repr a

type Derived (FinalizeSharing _letName repr)

Defined in Symantic.Typed.ObserveSharing

type Derived (FinalizeSharing _letName repr) = repr

Type LetBindings

type LetBindings letName repr = HashMap letName (SomeLet repr)

Class Letsable

class Letsable letName repr where

Minimal complete definition

Nothing

Methods

lets :: LetBindings letName repr -> repr a -> repr a

(lets defs x) let-binds (defs) in (x).

default lets :: Derivable repr => FromDerived1 (Letsable letName) repr => LetBindings letName repr -> repr a -> repr a

Instances

Letsable letName (ObserveSharing letName repr)

Defined in Symantic.Typed.ObserveSharing

Methods

lets :: LetBindings letName (ObserveSharing letName repr) -> ObserveSharing letName repr a -> ObserveSharing letName repr a