Hi Tilmann, On Wed, Jul 30, 2008 at 02:10:07PM +0200, Tillmann Rendel wrote:
Hi Markus,
Markus Barenhoff wrote:
I have written a parsec parser for reading a marshallaled dataformat.
The returned data structure is based on the following data type:
data T = TString String | TInt Integer | TList [TorrentT] | TDict [(TorrentT, TorrentT)]
I think TString and TInt are clear. The elements of a TList always have the same "type" (same constructor). The TDict is a dictionary where the key is always a TString but the value can be of any of the other "types", even in the same dictionary. F.e the key "foo" may map to a TInt while the key "bar" maps to another TDict.
Maybe something like
data T = TString String | TInt Integer | TStringList [String] | TIntList [Integer] | TDict [(String, T)]
mmm lists could also contain list or dict, so on must introduce constructors for those too. You will run in problems there because what is with a list of lists then you would need a TIntListList and so on... Maybe some words to the background why I use one type. This is to make the parsec parser work. The toplevel parser looks like this, because the parsed text could start with any of them:
parser :: GenParser Char st T parser = do stringParser <|> integerParser <|> listParser <|> dictParser
Markus -- Markus Barenhoff - Münster - Germany - Europe - Earth e-mail: alios@alios.org - jabber: alios@jabber.ccc.de - icq: 27998346