Extracting terminals in Transformer?

[alexthomasv]

I am trying to extract terminals in the Transform method. The way I have the rule set up is the following:

rel_op: "==" | "<" | ">" | "<=" | ">=" | "!=" | "<:" | "≠" | "≤" | "≥" I have a function:

def rel_op(self, items):
        # print("rel_op", items)
         return items

But it always prints out a []

Whenever I try to make this rule a terminal by capitalizing it to REL_OP and replacing it with all old occurrences of rel_op, I get the following...

lark.exceptions.UnexpectedToken: Unexpected token Token('LESSTHAN', '<') at line 155, column 16.

The rule: REL_OP: "==" | "<" | ">" | "<=" | ">=" | "!=" | "<:" | "≠" | "≤" | "≥" Why does changing the rule to a terminal now cause this issue?

Thank you!