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How to get the type of a value in haskell

I'm trying to debug and would like to be able to get a function that returns a value type. Is it possible?

I don't wan't: t, I can't something that can be used in the code

eg:

[showType i | i <- [0..5] ]

returns

[Int,Int,Int,Int,Int]
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2 answers


The class Typeable

encodes each type uniquely at compile time and can be used for this purpose:

import Data.Typeable

showType :: Typeable a => a -> String
showType = show . typeOf

with the result:



*Main> showType (+)
"Integer -> Integer -> Integer"
*Main> showType [1..5]
"[Integer]"
*Main> map showType [1..5]
["Integer","Integer","Integer","Integer","Integer"]

All that said, Beclilr is right. What you really want may be something else, so more information will help us help you.

+8


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Perhaps you want something like TypedHoles

. This allows you to write in _

place of some expression, and the compiler will tell you what type this hole has or should have.



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