modifying points style file


I just modifying / simplifying one quite complex points file. There are few lines which I don’t understand, I would like to keep things simple , but I wouldn’t like to broke some useful functionality.

place=city & population > 699999 & cityxx!=yes {set cityxx=yes} [0x0200 resolution 14 ]

What exactly cityxx!=yes and {set cityxx=yes} doing in this expresion?

cuisine = korean { set cuisinematch=no} [0x2a02 resolution 24 continue with_actions]
cuisine = thai { set cuisinematch=no} [0x2a02 resolution 24 continue with_actions]

What { set cuisinematch=no} doing here?

This line is from polygons file…

natural=water & water=reservoir & 20resolution!=yes {set 20resolution=yes} [0x3c resolution 24-16 ]

Why is & 20resolution!=yes {set 20resolution=yes} here?



The cityxx thing is an internal flag that whoever wrote this file is using to avoid applying the same rule twice. Basically it applies the rule, then sets cityxx to yes, which stops the rule then being applied again to the same object.
The other things you pick out are doing the same thing. They are internal flags being used by the style-writer to control how rules are applied to objects.

thank you for explanation

Any idea what this is doing?
& 20resolution!=yes {set 20resolution=yes}

Wild guess … setting different resolution for certain object?



Well that code is literally just setting a flag called 20resolution to yes. Somewhere else, there’ll be some code that actually does something interesting when the 20resolution flag is set to yes.