[Haskell] Re: Parameterized Show

Ben Rudiak-Gould Benjamin.Rudiak-Gould at cl.cam.ac.uk
Tue Nov 16 08:52:21 EST 2004

George Russell wrote:

 > Sorry, but I like implicit parameters, I use them, and I'm not going
 > to stop using them because beta conversion no longer preserves semantics.

You'll find that many people here don't agree with this view in general 
(though there's been surprisingly little backlash against implicit 
parameters in particular).

The idea of allowing local dictionaries is as old as type classes. It's 
a more obvious idea than what Haskell actually does, in fact. As far as 
I know, Haskell would have had local dictionaries from the beginning but 
for problems like those I listed. You won't be able to persuade the 
community to adopt them unless you can find a way to keep the various 
worms in the can.

 > It is very ingenious to encode complex configuration information by 
chains of types, but
 > it is something I recoil from in horror.

Lennart already answered this one. The part about round-tripping the 
runtime values through the type system, though ingenious, is not the 
part of the paper I want to preserve. :-)

-- Ben

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