In Haskell, the Typeable type class is used to get the type of an object. To use this type class, you must enable the DeriveDataTypeable extension with the {-# LANGUAGE DeriveDataTypeable #-} pragma at the top of your file.
Here's an example code snippet using Typeable type class to get the type of a value:
{-# LANGUAGE DeriveDataTypeable #-}
import Data.Typeable
-- Define a data type
data Person = Person { name :: String, age :: Int } deriving Typeable
-- Create an object of the Person type
person :: Person
person = Person { name = "Alice", age = 25 }
-- Get the type of the Person object
personType :: String
personType = show $ typeOf person
-- Print the type information
main :: IO ()
main = putStrLn personType
In the code above, Person is a custom data type with two fields, name and age. The Typeable type class is derived for the Person type using the deriving keyword.
The typeOf function is used to get the type information of the person object, which returns a TypeRep. The show function is then used to convert the TypeRep to a String that can be printed to the console.
When running the main action, the output will be: Person {name = "", age = 0}, which shows the type information of the person object.