Hello Pasqualino, Thursday, June 21, 2007, 11:22:19 AM, you wrote: more or less. there are Data and Typeable classes that provides this information but to use them you 1) should use GHC 2) should add "deriving Typeable" clause to declaration of each type you need to inspect 3) have "Typeable a" condition in definition of each function where you need this information: print_type :: (Typeable a) => a -> IO () so, its just something like class definition: class Typeable a where typename :: a -> String with GHC automatically deriving instances of this class. no real RTTI because Haskell data items are not objects. i suggest you to read paper before asking more questions :)
do you mean that as the type information is used only at compilation time and then thrown away there is no way of getting it back at execution time?
best,
titto
On Wednesday 20 June 2007 16:33:12 Bulat Ziganshin wrote:
Hello Pasqualino,
Wednesday, June 20, 2007, 11:30:32 AM, you wrote:
Most languages, even Java, have a reflection capability to dynamically inspect an object. It is surprising that Haskell doesn't offer it.
how about asm? :) there are no OOP objects in Haskell, each name is just an address of memory area. all operations are checked statically (at compile time). reflection capabilities may be only handmade - you can get any type info via hidden class dictionary (see http://homepages.inf.ed.ac.uk/wadler/papers/class/class.ps.gz for details of type classes implementation)
-- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com