Naming rule parts about lark

[akrasuski1]

On the other hand, this could be emulated by adding new non-terminals to the grammar (condition: expr in this case) and then use .find_data("condition") method. This is undocumented though, I only found it after looking at available methods.

[erezsh]

You're right, I should document the Tree class properly. I'll keep this issue open as a reminder.

Also, yes, if you want to name parts of a rule, it's better to turn these parts into separate rules. It's syntactically simpler, and easier to read.

[erezsh]

Added documentation here: https://github.com/erezsh/lark/wiki/Classes