Removal candidates in patterns

Duncan Coutts duncan.coutts at
Thu Jan 26 17:19:39 EST 2006

On Thu, 2006-01-26 at 17:01 +0000, Olaf Chitil wrote:

> Why are these patterns so hard to implement for Hat? Surely the Haskell 
> report gives a translation into simple core Haskell. Well, Hat does not 
> use this translation because it does not want to be an inefficient 
> pattern matcher (leave that job to the compiler) but produce a trace of 
> the Haskell program as it is written. However, both n+k and k patterns 
> cause calls of functions ( (-), (==) etc) that Hat has to record in its 
> trace.

Does it not have to do that for character and string patterns too?

I suppose that the proposals to create a string class and have
string/character constants overloaded by that class would cause similar
problems for Hat.


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