Proposal: Applicative => Monad: Call for consensus

wren ng thornton wren at freegeek.org
Mon Jan 17 01:08:59 CET 2011


On 1/16/11 12:43 PM, Henning Thielemann wrote:
> Maciej Piechotka schrieb:
>
>> I agree that there are advantages of both ways and they are perfectly
>> compatible with each other. While I don't know about GHC internals I'd
>> assume that class v-tables (term borrowed from C++ I'm not sure about
>> Haskell terminology) is per-class and not copied for each function
>> invocation.
>
> "Method dictionary"
>
> http://www.haskell.org/haskellwiki/OOP_vs_type_classes

Perhaps I missed it, but I don't see anything in that page clarifying 
whether the actual underlying table is shared (i.e., the dictionary is 
just a pointer to a global table) or not (i.e., the dictionary is a 
constructed copy of the table). As far as the surface language is 
concerned the distinction doesn't matter, but as far as people worrying 
about performance considerations due to the size of dictionaries it does.

-- 
Live well,
~wren



More information about the Libraries mailing list