[Distutils] FINAL DRAFT: Dependency specifier PEP

[Robert Collins]

On 18 November 2015 at 07:10, Paul Moore <p.f.moore at gmail.com> wrote:
> On 17 November 2015 at 17:32, Robert Collins <robertc at robertcollins.net> wrote:
>>> The only place where URIs are used seem to be the "urlspec" rule, and
>>> probably you can accept any opaque string there.
>>
>> Uhm, why are you making this suggestion? What problem will we solve by
>> using a proxy rule?
>
> I think the point here is syntax vs semantics. It is simpler to parse
> if we make the *syntax* state that an opaque string is allowed here.
> The *semantics* can then say that the string is to be handled as a
> URL, meaning that any string that isn't a valid URL will fail when we
> try to pass it to urllib or whatever.
>
> The only advantage of *parsing* it as a URL is that we get to reject
> foo::::/bar:baz as a syntax error. But we'd still reject foo:/bar as
> an invalid URL (unknown protocol) later in the processing, so why
> bother trying to trap the specific error of "doesn't look like a URL"
> early?
>
> By including the URL syntax, we're mandating that conforming
> implementations *have* to trap malformed URLs early, and can't defer
> that validation to the URL library being used to process the URL.

I don't understand how we're mandating that.

-Rob

-- 
Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
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