Re: [PATCH] Fix regex for determining image width from attribute

[Matt Huszagh]

Timothy <tecosaur@gmail.com> writes:

> What would be a more sensible interpretation in your mind? The “true” value
> depends on the number of columns, and fetching that information seems a bit
> unreasonable. Since this isn’t just used if nothing else if given, I see a 
> 120%
> interpretation as fairly reasonable.

I think there are several different questions/considerations here, which
I'll address in a second. But first, I think the essential disagreement
is whether org should take an action if not explicitly told to do so. I
think org should only perform some action if given a clear directive. In
this context, I feel that org is guessing what the user wants and taking
an action based on that guess.

Ok, back to the fact that there are multiple considerations here. The
first issue is whether specifying a width for a backend reflects an
intention to have that same width in the org buffer. As I previously
stated, I don't agree that one implies the other. But, as also
previously discussed, this was a decision that was made almost 10 years
ago, so changing it would be a breaking change, etc. Because of that,
I'm not totally sure what org should do, and I expect a lot of people
won't want to change this.

The other consideration is if we take the first point as a given (that
org should use width directives for other backends), should it also
attempt to interpret directives that are ambiguous? In this case, do we
interpret 1.2\somemacro as 1.2? If \somemacro could only be \linewidth,
I'd be inclined to agree that this is logical. I also understand the
case for \columnwidth, though this is slightly less clear. But, what if
someone used 1.2\columnsep? Seems a bit unusual I know, but maybe
someone would want this. Again, I don't think we should guess if there's
a chance we could be wrong.

I totally agree with you that we don't want to implement a pseudo latex
parser here. But I feel like all this complexity is easily resolved by
just requiring that people be explicit about their intentions (i.e.,
specify #+attr_org: :width). That would avoid all the complex behavior
and surprises that could result from making intelligent guesses about
what the user wants.

Anyway, let me know what you want in terms of the patch. I still think
prioritizing attr_org should be its own patch and changing the regex and
all the other behavior should be a separate issue. But, if you'd like me
to perform the change I mentioned in my last email, I can take the time
to write that up and include it in the same patch.

Thanks
Matt