==================
Comments
# x = 1;
# unassigned_variable
x # xyz
---
(source_file
(comment)
(expression
(identifier))
(comment))
Identifiers
variable_name
_unused_variable
__strange_format__
a
blahblah
x.x
(identifier)))
Operators
+ - = / & |
(operator)
(operator)))
Expressions
x_x = 1;
(integer)))