Okay, I have reconsidered, and I think I would be happy with top-level TWI's
providing they can be qualified on import, for example:
module Main where
import Library as L1
import Library as L2
main :: IO ()
main = do
L1.do_something_with_library
L2.do_something_with_library
Keean.
John Meacham wrote:
[i've cut this becuse its long...]
data AtomHash = ...
data Atom = ... (abstract)
instance Ord Atom
instance Eq Atom
newAtomHash :: IO AtomHash
toAtom :: AtomHash -> String -> IO Atom
fromAtom :: AtomHash -> Atom -> IO String
note a couple things:
1. The pure functions now are stuck in the IO monad, since I made their
dependence on AtomHash explicit, the fact that they modify AtomHash must
be made explicit by placing them in the IO monad. (it is possible to
come up with other formulations not in the IO monad, but they would have
similar problems) This alone is almost enough to kill the idea, but even
worse is the second
2. The fundamental property that there is an isomorphism between Atoms
and Strings is broken. because one might create multiple AtomHashs.
Suddenly what was a STATIC COMPILE TIME GUARENTEE becomes a run-time
obscure bug generating probelem.
furthermore, imagine you carefully avoided ever creating more than one
AtomHash, what purpose does it serve to pass everywhere then? it is
meerly a source of confusion and obfuscation. and someone could come
along to use your library, call 'newAtomHash' and break everything in a
way that would be very tricky to debug.
This is not a minor performance gain. in ginsu it dropped the memory
usage from > 100megs to 10megs. I would call that vital. when it used
100megs it was not a usable program.
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