There are several possibilities. The one that maps most closely to the expression you wrote is:

import Data.Typeable(typeOf) if typeOf a == typeOf (undefined :: Int) then f else g

Of course, f and g must have the same type. See http://haskell.org/ghc/docs/latest/html/libraries/base-3.0.0.0/Data-Typeable... for more details. Dan BOUNEB ZINE EL ABIDINE wrote:

Dear All ;

I look for the function which return the type of un element in Haskell :

For example

If type(a) = Int then f else g

Regards

--- BOUNEB ZINE EL ABIDINE wrote:

I look for the function which return the type of un element in Haskell :

For example

If type(a) = Int then f else g

Hello,I am Dan P. and I try to answer: If you want to get different effects, let's say different expression being evaluated according to the TYPE of the entity involved you may try to use: - a class - some instances of that class, every one having it's own definition of 'type' Let's start: Let's suppose f and g are two functions. First of all you can try to define your own class: class MyClass a b c where type :: a -> (b->c) So, for every element of type a, the value of type(a) will be a function. Let's suppose we know the signatures of f and g: something like (the same for both f and g) f:: Float -> Char g:: Float -> Char ----------------------------------------------------- | TO define the behaviour of type for a being an Int| | YOU HAVE TO INSTANTIATE the class MyClass and tell| | how can type will work ! | ----------------------------------------------------- instance MyClass Int Float Char where type _ = f For the other types (you did not specify them,sorry) for example for String other instances can be defined: instance MyClass String Float Char where type _ = g In this way the function 'type' became a polimorphically overrloaded function. -------------------------------------------- Simplified version. f::X and g :: X , X being a specific type. class SimpleClass a where type :: a -> X instance SimpleClass Int where type _ = f instance SimpleClass Char where type _ = g and so one for other types which can be the type of a. ----------------------------------------------- May be more solutions. Let's hope this will help. Dan ____________________________________________________________________________________ Be a better pen pal. Text or chat with friends inside Yahoo! Mail. See how. http://overview.mail.yahoo.com/