Re: ghc api / calling functions?

16 May 2006

      This seems to work fine. Thanks.

Couldn't find the source snippet in the hide sources online. I take it 
the source is from the ghc port you are working on right now? Are the 
sources available or do you need anybody to test? :)

Thanks again.

Lemmih wrote:
...
On 5/16/06, Maarten  wrote:
...
Is there a way to use the ghc api to call functions directly instead of
evaluating statements (more or less similar to hs-plugins)?
So far, thanks to some info pages, I have been able to load sessions and
make modules, however there seems to be little or no documentation on
calling functions directly. Any info/pointers appreciated. Thanks.
Here's some code from hIDE:
compileSymbol :: Session -> String -> IO (HValue, Type)
compileSymbol session symbol
   = do name <- fmap expectOneName (GHC.parseName session symbol)
        Just tything <- GHC.lookupName session name
        let globalId = getGlobalId  tything
        hscEnv <- GHC.sessionHscEnv session
        unlinked <- coreExprToBCOs (hsc_dflags hscEnv) (Var globalId)
        hvalue <- linkExpr hscEnv unlinked
        return (hvalue, idType globalId)
   where getGlobalId (AnId id) | isGlobalId id = id
         getGlobalId (AnId _) = error $ symbol ++ ": not a global id"
         getGlobalId (ADataCon _) = error $ symbol ++ ": is a data 
constructor"
         getGlobalId (ATyCon _) = error $ symbol ++ ": is a type 
constructor"
         getGlobalId (AClass _) = error $ symbol ++ ": is a class"
         expectOneName [x] = x
         expectOneName [] = error $ "No such symbol in plugin: " ++ 
symbol
         expectOneName _ = error $ "Ambiguous symbol in plugin: " ++ 
symbol