[Haskell-cafe] Preserving data type information

[Stephen Tetley]

Hi Andrey

Dynamic types are a possibility, if you want to handle an 'open set' of types:

http://www.haskell.org/ghc/docs/6.10.3/html/libraries/base/Data-Dynamic.html
&
http://people.cs.uu.nl/arthurb/dynamic.html

Although I don't see your use case as needing heterogeneous lists,
section 2 of the HList paper enumerates the design options available
for 'open types' (the authors conclude against dynamics in this case).

http://homepages.cwi.nl/~ralf/HList/

Best wishes

Stephen