[Mapcss] Strings and Keywords

[Sebastian Klein]

Andrew O. Shadoura wrote:
> Hello.
> 
> On Monday 19 July 2010 14:43:46 Sebastian Klein wrote:
>> what is the difference between strings and keywords and how are they
>> processed?
> 
> I think, there should be no difference between them. The keyword itself is a 
> string. If a string doesn't have non-keyword characters, it can be used 
> without quotes.

I think there is an agreement to start from css  (because it is widely
used and well supported) and only deviate when there is a reason.

In this case the reason could be that it is easier to implement. ;)

In css it is an error to write
 color: "red";
because red is a keyword:

http://www.w3.org/TR/CSS21/syndata.html#keywords


>> Another example would be the yes keyword in conditions. I'd say
>> [oneway=yes] applies to a oneway tag with value yes, true or 1, but
>> [oneway="yes"] matches the literal
>> value "yes", only.
> 
> My opinion on this is that we shouldn't do any magic, and that "yes" should be 
> the only "yes" but not "1" or "true". For "magic" comparison I'd write 
> something like boolean(oneway)=true, like in eval().

It is more or less a part of MapCSS 0.1 and 0.2. I don't like it that
much either, but with quotes it would at least be possible to suppress
the magic.

>> As keywords (unlike strings) are case insensitive, [oneway=Yes] would
>> work, but [Oneway=yes] or [oneway="Yes"] would not apply to a onway=yes
>>  tag.
> 
> Case insensivity is bad, I think.

Yes, but it is not a matter of opinion:

http://www.w3.org/TR/CSS21/syndata.html#characters

(Unless we agree that it is reasonable to differ from css in this point.)


Sebastian