How to force ANTLR to parse all input CharStream

Question

I\'m using ANTLR4 to parse a syntax file. When I use BaseErrorListener to detect errors, I got a problem. When faced with an illegal input string, ANTLR automatically matches th

Answer 1

Your main rule needs to end with the EOF token - an ANTLR-provided special token that matches end of input.

If the token's not there, ANTLR will just parse whatever it can match and then stop. By putting the EOF at the end of your entry rule, you tell ANTLR that whatever it parses must end at the end of input.