suggestion: add a .ehs file type

Alex Jacobson alex at
Tue Nov 20 16:35:30 EST 2007

If you take away -fglasgow-exts, then you force me to have to look up 
the exact name of each language extension I use every time I want to use 
it.  Since that is annoying and breaks flow, the simpler answer is just 
to put a big honking language pragma at the top of all my source files 
with every extension I commonly use.  e.g.

{-# LANGUAGE TemplateHaskell, FlexibleInstances,
              OverlappingInstances, UndecidableInstances, CPP,
              ScopedTypeVariables, PatternSignatures, GADTs,
              PolymorphicComponents, FlexibleContexts,
              MultiParamTypeClasses, DeriveDataTypeable,
              PatternGuards #-}

FYI, I grabbed the above from a source file that had been upgraded to 
6.8 in which I kept adding pragmas until it compiled.  Forcing the user 
to do this sort of thing manually every time they write code is 
ridiculous.  Taken to its logical conclusion, why don't we also add 
"RecordSyntax" and "DoSyntax" etc.

The compiler obviously knows which extensions are actually being used 
when the user uses them.  If you want to warn the user that they are 
using non-standard options that is totally ok, but forcing the user to 
type them in is just really unfriendly.


Neil Mitchell wrote:
> Hi Alex,
>> .ehs stands for extended haskell and encapsulates the 90% case of people
>> just wanting -fglasgow-exts with a minimum of fuss.
> That goes against the general GHC direction of trying to wean people
> off -fglasgow-exts and on to more specific language pragmas.
> Thanks
> Neil

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