sessions-2008.5.6: Session Types for Haskell Source code Contents Index

Control.Concurrent.Session.Runtime

Description

Having actually described a session type, you'll now want to implement it! Use the methods of SMonad to chain functions together.

Synopsis

data OfferImpls where OfferImplsNil :: OfferImpls Nil prog prog' finalState finalResult (~||~) :: forall prog prog' progOut progIn outgoing incoming finalState finalResult jumps l current currentUX. (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, ProgramToMVarsOutgoing prog prog progOut, ProgramToMVarsOutgoing prog' prog' progIn, SWellFormedConfig l (D0 E) prog, SWellFormedConfig l (D0 E) prog', TyListIndex progOut l (MVar (ProgramCell (Cell outgoing))), TyListIndex progIn l (MVar (ProgramCell (Cell incoming))), TyListIndex prog l currentUX, Expand prog currentUX current) => SessionChain prog prog' (current, outgoing, incoming) finalState finalResult -> OfferImpls jumps prog prog' finalState finalResult -> OfferImpls (Cons (Cons (Jump l) Nil) jumps) prog prog' finalState finalResult data SessionState where SessionState :: (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn) => prog -> prog' -> progOut -> progIn -> current -> MVar (Maybe (Chan ())) -> MVar (Cell currentOutgoing) -> MVar (Maybe (Chan ())) -> MVar (Cell currentIncoming) -> SessionState prog prog' (current, currentOutgoing, currentIncoming) newtype SessionChain prog prog' from to res = SessionChain { runSessionChain :: SessionState prog prog' from -> IO (res, SessionState prog prog' to) } sjump :: forall l prog prog' progOut progIn outgoing incoming current currentUX. (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, SWellFormedConfig l (D0 E) prog, SWellFormedConfig l (D0 E) prog', TyListIndex progOut l (MVar (ProgramCell (Cell outgoing))), TyListIndex progIn l (MVar (ProgramCell (Cell incoming))), TyListIndex prog l currentUX, Expand prog currentUX current) => SessionChain prog prog' (Cons (Jump l) Nil, Cons (Jump l) Nil, Cons (Jump l) Nil) (current, outgoing, incoming) () ssend :: forall t prog prog' nxt nxt' incoming. t -> SessionChain prog prog' (Cons (Send t) nxt, Cons t nxt', incoming) (nxt, nxt', incoming) () srecv :: forall t prog prog' nxt nxt' outgoing. SessionChain prog prog' (Cons (Recv t) nxt, outgoing, Cons t nxt') (nxt, outgoing, nxt') t soffer :: forall current outgoing incoming finalResult prog prog' jumps. OfferImpls jumps prog prog' (current, outgoing, incoming) finalResult -> SessionChain prog prog' (Cons (Offer jumps) Nil, Cons (Choice jumps) Nil, Cons (Choice jumps) Nil) (current, outgoing, incoming) finalResult sselect :: forall prog prog' progOut progIn label jumps outgoing incoming current currentUX len jumpTarget. (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, TyListLength jumps len, SmallerThanBool label len True, TypeNumberToInt label, TyListIndex jumps label (Cons (Jump jumpTarget) Nil), SWellFormedConfig jumpTarget (D0 E) prog, SWellFormedConfig jumpTarget (D0 E) prog', TyListIndex progOut jumpTarget (MVar (ProgramCell (Cell outgoing))), TyListIndex progIn jumpTarget (MVar (ProgramCell (Cell incoming))), TyListIndex prog jumpTarget currentUX, Expand prog currentUX current) => label -> SessionChain prog prog' (Cons (Select jumps) Nil, Cons (Choice jumps) Nil, Cons (Choice jumps) Nil) (current, outgoing, incoming) () run :: forall prog prog' progOut progIn init fromO fromI toO toI res res' currentUX currentUX' current current' toCur toCur'. (ProgramToMVarsOutgoing prog prog progOut, ProgramToMVarsOutgoing prog' prog' progIn, ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, SWellFormedConfig init (D0 E) prog, SWellFormedConfig init (D0 E) prog', TyListIndex progOut init (MVar (ProgramCell (Cell fromO))), TyListIndex progIn init (MVar (ProgramCell (Cell fromI))), DualT prog ~ prog', Dual prog prog', TyListIndex prog init currentUX, Expand prog currentUX current, TyListIndex prog' init currentUX', Expand prog' currentUX' current') => prog -> init -> SessionChain prog prog' (current, fromO, fromI) (toCur, toO, toI) res -> SessionChain prog' prog (current', fromI, fromO) (toCur', toI, toO) res' -> IO (res, res') class ProgramToMVarsOutgoing progRef prog mvars | progRef prog -> mvars where type ProgramToMVarsOutgoingT progRef prog programToMVarsOutgoing :: progRef -> prog -> IO mvars data ProgramCell data Cell

Documentation

data OfferImpls where Source

Use OfferImpls to construct the implementations of the branches of an offer. Really, it's just a slightly fancy list. Constructors OfferImplsNil :: OfferImpls Nil prog prog' finalState finalResult

(~||~) :: forall prog prog' progOut progIn outgoing incoming finalState finalResult jumps l current currentUX. (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, ProgramToMVarsOutgoing prog prog progOut, ProgramToMVarsOutgoing prog' prog' progIn, SWellFormedConfig l (D0 E) prog, SWellFormedConfig l (D0 E) prog', TyListIndex progOut l (MVar (ProgramCell (Cell outgoing))), TyListIndex progIn l (MVar (ProgramCell (Cell incoming))), TyListIndex prog l currentUX, Expand prog currentUX current) => SessionChain prog prog' (current, outgoing, incoming) finalState finalResult -> OfferImpls jumps prog prog' finalState finalResult -> OfferImpls (Cons (Cons (Jump l) Nil) jumps) prog prog' finalState finalResult Source

Use to construct OfferImpls. This function automatically adds the necessary sjump to the start of each branch implementation.

data SessionState where Source

Constructors SessionState :: (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn) => prog -> prog' -> progOut -> progIn -> current -> MVar (Maybe (Chan ())) -> MVar (Cell currentOutgoing) -> MVar (Maybe (Chan ())) -> MVar (Cell currentIncoming) -> SessionState prog prog' (current, currentOutgoing, currentIncoming)

newtype SessionChain prog prog' from to res Source

The representation of a computation that performs work using session types. Again, really quite similar to a more-parameterized State monad. Constructors SessionChain runSessionChain :: SessionState prog prog' from -> IO (res, SessionState prog prog' to) Instances SMonadIO (SessionChain prog prog') SMonad (SessionChain prog prog')

sjump :: forall l prog prog' progOut progIn outgoing incoming current currentUX. (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, SWellFormedConfig l (D0 E) prog, SWellFormedConfig l (D0 E) prog', TyListIndex progOut l (MVar (ProgramCell (Cell outgoing))), TyListIndex progIn l (MVar (ProgramCell (Cell incoming))), TyListIndex prog l currentUX, Expand prog currentUX current) => SessionChain prog prog' (Cons (Jump l) Nil, Cons (Jump l) Nil, Cons (Jump l) Nil) (current, outgoing, incoming) () Source

Perform a jump. Now you may think that you should indicate where you want to jump to. But of course, that's actually specified by the session type so you don't have to specify it at all in the implementation.

ssend :: forall t prog prog' nxt nxt' incoming. t -> SessionChain prog prog' (Cons (Send t) nxt, Cons t nxt', incoming) (nxt, nxt', incoming) () Source

Send a value to the other party. Of course, the value must be of the correct type indicated in the session type.

srecv :: forall t prog prog' nxt nxt' outgoing. SessionChain prog prog' (Cons (Recv t) nxt, outgoing, Cons t nxt') (nxt, outgoing, nxt') t Source

Recieve a value from the other party. This will block as necessary. The type of the value received is specified by the session type. No magic coercion needed.

soffer :: forall current outgoing incoming finalResult prog prog' jumps. OfferImpls jumps prog prog' (current, outgoing, incoming) finalResult -> SessionChain prog prog' (Cons (Offer jumps) Nil, Cons (Choice jumps) Nil, Cons (Choice jumps) Nil) (current, outgoing, incoming) finalResult Source

Offer a number of branches. This is basically an external choice - the other party uses sselect to decide which branch to take. Use OfferImpls in order to construct the list of implementations of branches. Note that every implementation must result in the same final state and emit the same value.

sselect :: forall prog prog' progOut progIn label jumps outgoing incoming current currentUX len jumpTarget. (ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, TyListLength jumps len, SmallerThanBool label len True, TypeNumberToInt label, TyListIndex jumps label (Cons (Jump jumpTarget) Nil), SWellFormedConfig jumpTarget (D0 E) prog, SWellFormedConfig jumpTarget (D0 E) prog', TyListIndex progOut jumpTarget (MVar (ProgramCell (Cell outgoing))), TyListIndex progIn jumpTarget (MVar (ProgramCell (Cell incoming))), TyListIndex prog jumpTarget currentUX, Expand prog currentUX current) => label -> SessionChain prog prog' (Cons (Select jumps) Nil, Cons (Choice jumps) Nil, Cons (Choice jumps) Nil) (current, outgoing, incoming) () Source

Select which branch we're taking at a branch point. Use a type number (Control.Concurrent.Session.Number) to indicate the branch to take.

run :: forall prog prog' progOut progIn init fromO fromI toO toI res res' currentUX currentUX' current current' toCur toCur'. (ProgramToMVarsOutgoing prog prog progOut, ProgramToMVarsOutgoing prog' prog' progIn, ProgramToMVarsOutgoingT prog prog ~ progOut, ProgramToMVarsOutgoingT prog' prog' ~ progIn, SWellFormedConfig init (D0 E) prog, SWellFormedConfig init (D0 E) prog', TyListIndex progOut init (MVar (ProgramCell (Cell fromO))), TyListIndex progIn init (MVar (ProgramCell (Cell fromI))), DualT prog ~ prog', Dual prog prog', TyListIndex prog init currentUX, Expand prog currentUX current, TyListIndex prog' init currentUX', Expand prog' currentUX' current') => prog -> init -> SessionChain prog prog' (current, fromO, fromI) (toCur, toO, toI) res -> SessionChain prog' prog (current', fromI, fromO) (toCur', toI, toO) res' -> IO (res, res') Source

Run! Provide a program and a start point within that program (which is automatically sjumped to), the two implementations which must be duals of each other, run them, have them communicate, wait until they both finish and die and then return the results from both of them.

class ProgramToMVarsOutgoing progRef prog mvars | progRef prog -> mvars where Source

Associated Types type ProgramToMVarsOutgoingT progRef prog Source Methods programToMVarsOutgoing :: progRef -> prog -> IO mvars Source Instances ProgramToMVarsOutgoing ref Nil Nil (Outgoing val'' ~ val', ProgramToMVarsOutgoing ref nxt nxt', TyList nxt, TyList nxt', Expand ref val val'') => ProgramToMVarsOutgoing ref (Cons val nxt) (Cons (MVar (ProgramCell (Cell val'))) nxt')

data ProgramCell Source

data Cell Source

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