[Haskell-cafe] Type Directed Name Resolution

Malcolm Wallace malcolm.wallace at me.com
Fri Nov 12 15:33:39 EST 2010


On 12 Nov 2010, at 20:21, Andrew Coppin wrote:

> On 11/11/2010 08:43 PM, Richard O'Keefe wrote:
>> If length, map, and so on had always been part of a Sequence
>> typeclass, people would not now be talking about
>
> It's always puzzled me that Haskell's standard containers almost  
> completely lack any way to use them polymorphically.

On the contrary, there is the Edison package of containers and  
algorithms, since at least the late 90's, which has type classes for  
all of the common operations.  It is high quality, and kind-of the  
"ideal standard" in an academic sort of way, except that almost nobody  
uses it.  In particular, ghc did not use it internally, choosing  
Data.Map instead, and the legendary suspicion of programmers who  
refuse to use a alternative library replacing one that already comes  
with their compiler, means that nobody else did either.  Either that,  
or people find it awkward to deal with the substantial extra  
hierarchies of type classes.

Edison-API and Edison-core are available on hackage by the way.

Regards,
     Malcolm


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