I have 2 simple lexer rules in my ANTLR4 grammar:
fragment Attrs : '.' ARCH;
fragment ARCH : 'IA32' | 'X64' | 'IPF' | 'EBC' | 'common';
The generated ATN with ANTLR4.7 is like this (Visual Studio Code):
I searched some references about "ATN", such as this one.
It's beautiful but I don't understand it:
- What does the number and label in the node mean?
- What does the epsilon symbol on the arrow line mean?
- What do the grey and red nodes mean?