mapcss: prop() in selector doesn't work together with child selector

[Klumbumbus]

The following mapcss code is not working:

*
{
	help: tag("addr:housenumber");
}

way[prop(help)>3] > node
{
	symbol-shape: circle;
	symbol-size: 20;
}

The result should look like:

Tested with JOSM stable 7000 and latest 7080.

[bastiK]

This is more or less by design, you can only access the properties of the current object (the node in this case).

Could you give a practical example where this feature would be indispensable? (I'm asking because it would be quite difficult to support this, given how the algorithm works at the moment.)

Maybe there are other ways to achieve the same?

[Klumbumbus]

Thanks for the explanation.
See the following gif, which is an example of the mappaint style ColouredStreets.
​gif
As you can see, the nodes on housenumber 5 and 18 are hardly to recognize (because yellow on yellow). So I want to change the colour of these nodes. I found a solution for this with the following code

way["addr:street"]  > node
{
	crc: CRC32_checksum(parent_tag("addr:street"))/429496.7296;
}
way > node[prop(crc)>=1212][prop(crc)<1515],
way > node[prop(crc)>=5151][prop(crc)<5454]
{
	symbol-stroke-color: limegreen;
}

So no need to make any changes to the JOSM code. Maybe a hint in ​mapcss documentatin would be good, that prop() on the left side of a child selector doesn't work.