RE: Re[2]: [Haskell-cafe] newbie type signature question

From: Bulat Ziganshin [mailto:bulat.ziganshin@gmail.com]

when you work with C++ or some other OOP language, you can define that some field in structure should some some specific interface and this allows to use functions of this interface on this field. i required the same feature in Haskell, for example:

I come from a C++ background, and there is no formal way in the language to specify constraints for type (template) parameters; a major weakness for generic programming. Some interesting work is being done to add this ability though, ex: http://www.boost.org/libs/concept_check/concept_check.htm. Regards, Brock