[Ur] typechecker rejects form handler

[Sergey Mironov]

I've redesigned my program - merged two functions (`pnew' and `pview')
into one. Form handler is no longer parametrized with functions
returning urls so urweb doesn't have to duplicate it anymore. Example
compiles fine, Thanks!

If I understand correctly, it is the two specialized versions of
`validator' which cause problems in my example. But does this mean
that specializations are not usable in practice at the moment? Do you
plan to introduce some kind of automatic names generator for cases
like this one? I think, it would be fine If urweb had made two urls
(say, `validator0' and `validator1' ) out of two static copies of
`validator' in my example. I vote for this improvement until there are
counterexamples demonstrating how this improvement may violate the
security or confuse something.

Regards,
Sergey


2014/1/4 Adam Chlipala <adamc at csail.mit.edu>:
> On 01/04/2014 01:57 PM, Sergey Mironov wrote:
>>
>> Wow, sorry for that. Unfortunately, it is not my only trouble with
>> this sample. Please, see FormBug2.ur (in attach). I've replaced !=
>> with `eq' call.
>> The new errors are
>>
>>   $ urweb -dbms sqlite FormBug2
>>   :0:0: (to 0:0) Duplicate HTTP tag validator
>>
>
>
> Your code needs to create URLs referencing the function [validator], but
> multiple versions of it must exist due to multiple (static) calls to its
> enclosing function, and they'd all get the name "validator" in URLs.  Try
> making the enclosing function a functor instead, so you get to choose a
> module name for its outputs manually, providing the compiler with advice
> about namespacing.