[Haskell-cafe] Re: [Haskell] View patterns in GHC: Request forfeedback

Rene de Visser Rene_de_Visser at hotmail.com
Mon Jul 23 14:39:10 EDT 2007

>> Simon PJ and I are implementing view patterns, a way of pattern matching
>> against abstract datatypes, in GHC.  Our design is described here:
>> http://hackage.haskell.org/trac/ghc/wiki/ViewPatterns
>> If you have any comments or suggestions about this design, we'd love to
>> hear them.  You can respond to this list (and we can take it to
>> haskell-cafe if the thread gets long) or, if you prefer, directly to me.
I find the => operator excessive. GHC Haskell seems to be growing too 
rapidly syntax wise in my opinion.
The important features of code are correctness, maintainability and 
readibility (IMHO), and I think => is working against these.

=> uses up more syntax. Buys very little. Equivalent to "-> Just _ " or "-> 
Just x " as far as I can see.
I would prefer to type the extra 6 characters rather than having the hidden 
It is also one more thing to learn. One more confusing type error when you 
mix them up.


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