While what you say is true, GHC is the de facto Haskell standard. At least the last time I looked, most widely used and well respected Haskell code would only work in GHC using various extensions. That's the actual state of Haskell: GHC with non-standard extensions is the effective standard.
An extension that GHC provides, and therefore part of the effective standard, is Safe Haskell (http://www.haskell.org/ghc/docs/7.4.2/html/users_guide/safe-...). A Safe (compiled with -XSafe, containing the LANGUAGE Safe pragma, or inferred) module may not define any manual instances of Typeable.
Comments
While what you say is true, GHC is the de facto Haskell standard. At least the last time I looked, most widely used and well respected Haskell code would only work in GHC using various extensions. That's the actual state of Haskell: GHC with non-standard extensions is the effective standard.
An extension that GHC provides, and therefore part of the effective standard, is Safe Haskell (http://www.haskell.org/ghc/docs/7.4.2/html/users_guide/safe-...). A Safe (compiled with -XSafe, containing the LANGUAGE Safe pragma, or inferred) module may not define any manual instances of Typeable.
There are widely used extensions and there are avoided extensions:
http://stackoverflow.com/questions/801785/should-i-use-ghc-h...