The Haskell type inference feature I'd really like to see
I'd like to be able to write something like
map zipWith ([1,2,3] >>= printMyInferredType)
and have the compiler treat 'printMyInferredType' as undefined, but also produce the side effect of printing out its inferred type. What's the easiest way to simulate this with what we have now? -- Dan
On Fri, Oct 24, 2008 at 01:38:23PM -0700, Dan Piponi wrote:
I'd like to be able to write something like
map zipWith ([1,2,3] >>= printMyInferredType)
and have the compiler treat 'printMyInferredType' as undefined, but also produce the side effect of printing out its inferred type.
What's the easiest way to simulate this with what we have now?
This will work as long as your type has a typeable instance. You can modify it to work in an non-io context with unsafePerformIO (as long as you are aware of the caveats of doing so) import Data.Typeable printInferedType :: Typeable a => a -> IO () printInferedType x = print (typeOf x) main = do printInferedType () printInferedType "foo" -- John Meacham - ⑆repetae.net⑆john⑈
participants (2)
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Dan Piponi -
John Meacham