[spec] comments on the proposed gemini spec revisions

[Omar Polo]

Oliver Simmons <oliversimmo at gmail.com> writes:

> On Mon, 11 Oct 2021 at 09:12, Omar Polo <op at omarpolo.com> wrote:
>> 1. whitespace after gemtext elements
>>
>> I don't have strong opinion on this, but on the other hand I don't see a
>> real motivation to require a space in your post nor in the gitlab
>> discussion.  Whitespaces should not be mandatory if not strictly
>> required to separate fields (like in a link line) in my opinion at
>> least.  But yes, I do always write '# hello there' and not '#hello
>> there'.
>
> As someone who's making a basic gemini client, having the whitespace
> makes it alot simpler, you can just split the line on the space and do
> a `switch` on the first part.
> Not having a space means you'd have to test if the line starts with
> different things, which would be very annoying and slower in most
> cases.
> Having the whitespace is easier for clients,

I've seen this argument in the gitlab issue too, but sorry, I don't
believe it.  In what language(s) splitting a string is faster than
checking for a prefix?  Splitting requires the allocation of multiple
objects, while the prefix only requires a scan of the first few bytes.

To be more precise: splitting on a space will always be slower than
checking for a prefix even if we ignore the cost of allocating the
strings because you'd have to first scan the string for the first space
(which can be far into the line) and then the cost of comparing strings
(i.e. another scan) while checking for a prefix requires always to only
compare the first few bytes.

Even if we eventually decide to mandate a whitespace, checking for a
prefix would still lead to better and faster code.

> and also looks better.

I totally agree!  It *absolutely* looks better, but I think we shouldn't
account for aesthetic too much in the spec, as they tend to change from
time to time and from one person to another.

> I see no downside to enforcing it in the spec (a SHOULD or MUST).

My argument is kind the opposite: if there isn't a (strong) reason for
requiring something, then that something MUST be optional.  Whitespaces
are required in the link line to separate unambiguously the link from
the label, the other whitespaces in the "special" lines don't serve this
purpose so they need to be completely optional.