[Mapcss] relative width for overlays

[Komяpa]

> But as I said, it would be just a shortcut and nothing that is needed at all
> costs.

Okay, I agree.

Then, we've got two shortcuts already:
1) text: xxx -> text: eval(tag("xxx"))
2) anything: [+/-]zzz -> eval(num(prop("anything"))+zzz)

and adding a second parameter to prop() that points to sublayer to
take data from, defaulting to current.

Any objections?

What worries me the most is - do all the common languages with
mapcss-compatible eval syntax have ability to have different argument
count for function, or is there any easy way to transform it?

-- 
Darafei "Komяpa" Praliaskouski
OSMF BY Team
xmpp:me at komzpa.net mailto:me at komzpa.net