Hi people,
I'm embedding Haskell into a C program with a "stateful objects with
message passing" paradigm [0]. I want to make "boxes" with useful
functions, then connect them together within the C program. I know how
to build a working version using Data.Dynamic, but that loses
polymorphism [1].
Say I have 3 boxes:
Box 1: [1,2,5,3] :: [Float]
Box 2: reverse :: [a] -> [a]
Box 3: putStrLn . show :: (Show b) => b -> IO ()
I wonder, is it possible to create these boxes separately at runtime
(each box being compiled/loaded separately with hsplugins), then connect
them together like {Box 1}=>{Box 2}=>{Box 3} (with a wrapping layer
doing appropriate type checking/error reporting), or does the whole
thing need to be compiled statically to generate specialized variants of
the polymorphic functions? As hinted in #haskell :
<quicksilver> ClaudiusMaximus: I don't think anything will allow you to
pass around polymorphic values. They're an illusion of the type-checker,
in a sense.
Thanks for any insights,
Claude
[0] http://puredata.info
[1] Data.Dynamic> (fromDynamic (toDyn (3.5::Double)))::(Typeable a =>
Maybe a)
<interactive>:1:0:
Ambiguous type variable `a' in the constraint:
`Typeable a'
arising from instantiating a type signature at <interactive>:1:0-59
Probable fix: add a type signature that fixes these type variable(s)
--
http://claudiusmaximus.goto10.org
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