Simon M has persuaded me that -D/-U are really cpp-specific flags. What's to stop you using the environment variables directly? Suppose you had getEnvVar :: String -> Q (Maybe String) which is pretty much what System.getEnv does. Would that do the job? Then you could say DEBUG=yes ghc -fth Foo.hs Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users- | bounces@haskell.org] On Behalf Of George Russell | Sent: 02 December 2003 15:32 | To: glasgow-haskell-users@haskell.org | Subject: Template Haskell and the command line | | Template Haskell is frightfully good and we want to get rid of cpp and | use it instead, but there's one tiny problem, namely that for cpp it | is possible to define variables on the command line (-DSIMON=MARLOW and so | on) while with Template Haskell it doesn't seem to be. Could there be | some kind of dictionary, like the cpp environment variables, which the | Template Haskell code has access to? | | One obvious way would be to accept the -D/-U arguments, and provide Haskell | functions which look at them. | | Of course one /could/ presumably use System.getArgs and analyse the arguments | to ghc oneself, but that would mean making guesses about the current GHC syntax. | | In the meantime we shall still replace cpp with Template Haskell, but find | another way. Thanks for Template Haskell! | | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users