Hi!

2013/3/9 Tom Davie <[email protected]>:
>> * text-offset is also supported as text-offset-y in JOSM; furthermore
>> there is a property text-offset-x, but I don't really can think of a
>> use-case for this.
>
> Personally what I'd like to see is the user being able to specify label 
> placement techniques, and methods of deciding priority on labels.  That is, 
> if they want to see the names of minor roads – let them, it shouldn't be up 
> to the renderer to decide that major roads are more important.

That's a very good point indeed.


>> * The MapCSS specifications seems to lack the property "offset" from
>> JOSM, which moves the line left or right. This is a very important
>> property!
> I'm not convinced I can think of a use case for it, but if you say so.

Have a look at the screenshot here:
http://josm.openstreetmap.de/wiki/Styles/Lane_and_Road_Attributes
All the lanes use the property offset.


>> Improvements needed to process data:
>> Obviously from the number of built-in functions in JOSM there is a
>> strong need of more processing capabilities. Arrays, loops, nested if
>> statements are just a few of them. As I'm not really a fan of
>> reinventing the wheel again and again I want to suggest something and
>> hear your opinions. Here's an example which should make clear what I
>> have in mind:
>
> No, the design philosophy here is entirely wrong.

Shouldn't the design philosophy be targeted at the use-cases?


> MapCSS is a declarative language.  That means, you say "given this input, the 
> result is this", not "to compute the result from this input do this then this 
> then this".  This has significant benefits to implementors, and to clarity of 
> stylesheets.  If you want to invent MapJavascript, do so, but MapCSS is not 
> the place to put it.

I don't want to invent MapJavascript. I - and I guess some others -
need more processing power. Why should we invent something new (did I
already mention I don't like to reinvent the wheel again?) instead of
taking something that works and add what is needed? The approach would
be fully backward-compatible, use existing code (for the javascript
interpreter) and tremendously increase the abilities of MapCSS.

Take a look at the code of the JOSM style. Doesn't this look very
1970ish? Or even 1960ish? For example the style supports eight lanes
in each direction. Why eight? Because I wrote the code for the first
lane and copied it seven times. I wouldn't use the word "elegant" for
this.


> For reference, OpenStreetPad already supports nested selectors, allowing you 
> to do things like this (in a declarative form):
> .........

Nice but too less. Where are loops and arrays? We have an increasing
number of tags that contain multiple information. For example all tags
like turn:lanes or change:lanes contain a list of properties. Some
people need to get a list of all relations attached to a way. We are
completely missing the power to process such information in an
efficient way. Of course we can increase the number of eval-built-in
functions. But I'm asking again: why reinventing the wheel?

best regards,
Martin

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