You've given multiplication a higher precedence than division. Usually, these have the same precedence. I.e., the expression 1 / 2 * 3 is usually evaluated as (1 / 2) * 3 (from left to right), which is 1.5. But in your case, it will be evaluated as 1 / (2 * 3), which is 0.16666666666.
Also, your...
Great advice except for the whole matching one or more expressions thing. Without that + the grammar won't generate. It complains about being left recursive. Thanks for the advice! Nice review.
Well, that's a very good point. I'll have to add those cases to my tests and see what I can do to fix it. (along with the order of multiplication/division and addition/subtraction).
Oh wow. Actually, since I'm stripping white space, that would get read in as 1+12-23*3...
No, the whitespace trimming would only kick in at the parser-level. I.e. your parser would receive 9 tokens: 1, +, 1, 2, -, 2, 3, *, 3, not 7 tokens 1, +, 12, -, 23, *, 3.
You either found a bug in ANTLR, or doing something incorrect in your code because that should not happen. What happens when you run for (Token token : lexer.getAllTokens()) { System.out.println(token); } on the input?
Yes, I ran the code. I'm posting the actual output of running the code (the Java code, that is).
Discussion between RubberDuck and Bar…
Discussion between RubberDuck and Bar…