MapCSS: min() and max()

[plepe]

The eval-functions min() and max() are supported all right in MapCSS. As JOSM also supports lists, it would be nice if I could pass a list to both of this functions and return the smallest (or highest) number.

[simon04]

In 7165/josm:

see #10063 - MapCSS: add min() and max() according to standard

[simon04]

r7165 allows to specify for instance:

* {
  min_value: min(tag(x), tag(y), tag(z));
  max_value: max(tag(x), tag(y), tag(z));
}

At the moment, this evaluates to NaN/null if one argument is not defined.

Did you have a different use-case in mind?

[plepe]

Yes, I have different use-case in mind. See this example "Highest Peaks" on ​https://github.com/plepe/pgmapcss/tree/master/examples (which doesn't work for JOSM right now for several reasons - it's quite pgmapcss specific).

I collect the elevation (Tag "ele") of all peaks near the current (child) peak in a list and then I take the maximum element of this list to see if the current peak is higher than all nearby peaks.

In pgmapcss I implemented min(...) to either take several parameters and then return the smallest parameter OR take a single parameter which is interpreted as list (and then the smallest list member).

[simon04]

In 7170/josm:

fix #10063 - MapCSS: make min() and max() work on a list as well

For instance, max(split(";", tag(widths))) splits the tag widths on semicolons and determines the largest numeric value