[Haskell-cafe] list of range

Hello, I need to parse a commande line which allows user to describe indices like this 1 -> only one indice 1-5 -> [1..5] 1-5 6-10 ...-> [1..5] ++ [6..10] My question is what it the best type in order to store this information ? Range Int = Range Int | RangeFromTo Int Int | Range Int <+> Range Int At some point I would like to add the possibility to have multiples Indices with the ',' 1,3,5 -> [1,3,5] list of indices This type is used at some point as a List. My question is, are you aware of a similar type in the standar library. This is the kind of information tahth w should parse when we request to print pages. (list of pages to print). Cheers Frederic