Records in Haskell

wren ng thornton wren at freegeek.org
Sun Feb 26 11:00:04 CET 2012


On 2/26/12 12:38 AM, Anthony Clayden wrote:
> Wren/all
>
> Please remember SPJ's request on the Records wiki to stick
> to the namespace issue. We're trying to make something
> better that H98's name clash. We are not trying to build
> some ideal polymorphic record system.

I believe my concern is a namespace issue. There are certain 
circumstances under which we do not want names to clash, and there are 
certain circumstances under which we do want them to clash; just as 
sometimes we want things to be polymorphic and sometimes not.

I haven't been following all the different proposals out there, but the 
ones I did see before tuning-out all took the stance that for each given 
field either (1) this field name is unique and always clashes, or (2) 
this field name is shared and never clashes. This is problematic for a 
number of reasons. The particular reason I raised is that there are 
times when we would like for a field name to be shared, but only shared 
among a specified group of records and clashing with all other records 
(which may themselves form groups that share the name as well).

That's not a complaint against DORF per se. I haven't read the DORF 
proposal, so perhaps it already handles this issue. Rather, it's a 
general concern that I haven't seen discussed very much while skimming 
this thread.

-- 
Live well,
~wren



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