Re: RFC on Fragment Directives

On Fri, Sep 6, 2019 at 11:26 PM David Bokan <bokan@chromium.org> wrote:

> On Thu, Sep 5, 2019 at 1:28 PM Roy T. Fielding <fielding@gbiv.com> wrote:
>
>> On Sep 5, 2019, at 10:09 AM, Roy T. Fielding <fielding@gbiv.com> wrote:
>>
>> On Sep 5, 2019, at 9:37 AM, David Bokan <bokan@chromium.org> wrote:
>>
>> Hello all,
>>
>> I'd like to get some broader feedback on the proposal of a "fragment
>> directive". The basic idea is to encode a section of the URL fragment for
>> "UA instructions". e.g.
>>
>> https://example.org#fragment##fragment-directive
>> <https://example.org/#fragment%23%23fragment-directive>
>>
>>
>> Absolutely not. Only one # is allowed in a reference because some
>> implementations parse
>> left-to-right (correctly) and others parse right-to-left (incorrectly),
>> and there is absolutely
>> nothing you can say or do that will ever make that interoperable in
>> practice.
>>
>> I see, thanks for explaining; I was wondering where the restriction came
> from. By chance, is there
> a place documenting the history and the reasoning behind these kinds of
> decisions? I'd be curious to
> learn more.
>

Just to close the loop here, we've changed the proposal to use a different
delimiter:

https://example.org#fragment:~:fragment-directive

This one uses only valid code-points and is defined entirely in HTML
fragment processing so there
are no changes to the URL spec required. We've done some careful analysis
and believe this should
be web compatible. Thanks for the feedback!

See https://github.com/WICG/ScrollToTextFragment for details. Any
additional feedback or comments
there are welcome.

-David