On 25 August 2004 12:28, MR K P SCHUPKE wrote:

I wish to add some extended syntax to type definitions, assuming I modify the parser files and associated datatypes to carry the extra information, is there a convenient place to insert a pre-parse (before type-checking) to convert the syntax extensions to regular haskell?

GHC's strategy is to not do any translation before typechecking, so that we can generate good error messages. Nevertheless, it's certainly possible to do what you're suggesting: just insert an HsSyn->HsSyn pass after parsing (I imagine). Various things might complicate matters, such as needing to refer to fixed entities in other modules in the translation. Cheers, Simon