main/InteractiveEvalTypes.hs

    -- -----------------------------------------------------------------------------
    --
    -- (c) The University of Glasgow, 2005-2007
    --
    -- Running statements interactively
    --
    -- -----------------------------------------------------------------------------

    module InteractiveEvalTypes (
    #ifdef GHCI
            RunResult(..), Status(..), Resume(..), History(..),
    #endif
            ) where

    #ifdef GHCI

    import Id
    import BasicTypes
    import Name
    import RdrName
    import TypeRep
    import ByteCodeInstr
    import SrcLoc
    import Exception
    import Control.Concurrent

    data RunResult
      = RunOk [Name]                -- ^ names bound by this evaluation
      | RunException SomeException  -- ^ statement raised an exception
      | RunBreak ThreadId [Name] (Maybe BreakInfo)

    data Status
       = Break Bool HValue BreakInfo ThreadId
              -- ^ the computation hit a breakpoint (Bool <=> was an exception)
       | Complete (Either SomeException [HValue])
              -- ^ the computation completed with either an exception or a value

    data Resume
       = Resume {
           resumeStmt      :: String,       -- the original statement
           resumeThreadId  :: ThreadId,     -- thread running the computation
           resumeBreakMVar :: MVar (),
           resumeStatMVar  :: MVar Status,
           resumeBindings  :: ([TyThing], GlobalRdrEnv),
           resumeFinalIds  :: [Id],         -- [Id] to bind on completion
           resumeApStack   :: HValue,       -- The object from which we can get
                                            -- value of the free variables.
           resumeBreakInfo :: Maybe BreakInfo,
                                            -- the breakpoint we stopped at
                                            -- (Nothing <=> exception)
           resumeSpan      :: SrcSpan,      -- just a cache, otherwise it's a pain
                                            -- to fetch the ModDetails & ModBreaks
                                            -- to get this.
           resumeHistory   :: [History],
           resumeHistoryIx :: Int           -- 0 <==> at the top of the history
       }

    data History
       = History {
            historyApStack   :: HValue,
            historyBreakInfo :: BreakInfo,
            historyEnclosingDecls :: [String]  -- declarations enclosing the breakpoint
       }
    #endif