How to implement EOF in Antlr4 Grammar - tsql

Question

I have a grammar that I am using for TSQL-esque language validation. Currently the grammar rules will work with a statement such as SUM(column1) + SUM(column2).
I would like the parser to throw an error if it was given something like
SUM(column1) SUM(column2). Notice the lack of an operator between the two SUMs. Right now, if I run this statement through the parser it does not error out. Instead it will return the first part of the statement, SUM(column1) and completely disregard the rest of the statement.
Upon research, I believe the answer to my problem is adding a EOF to my grammar. I have tried to implement this in several ways but it has not made any difference to the parsing.
This is the best way I can think to implement it in my grammar file, in the argument_list:
grammar DataAnalysis;
expression : literal #literalAtomExp
| FUNCTION=ID '(' argument_list ')' #functionExp
| INLINE_FUNCTION '(' argument_list ')' #inlineFunctionExp
| '(' expression ')' #parenthesisExp
| expression (ASTERISK|SLASH) expression #mulDivExp
| expression (PLUS|MINUS) expression #addSubExp
| <assoc=right> expression '^' expression #powerExp
| QUOTEDTEXT #stringExp
;
argument_list : expression (',' expression)* EOF //implemented here
;
literal : (TABLE_NAME=ID '.')? COLUMN_NAME=ID
| VALUE=NUMBER
;
fragment NAME : [a-zA-Z0-9_] ;
fragment LETTER : [a-zA-Z] ;
fragment DIGIT : [0-9] ;
ASTERISK : '*' ;
SLASH : '/' ;
PLUS : '+' ;
MINUS : '-' ;
INLINE_FUNCTION : 'YEAR'
| 'MONTH'
| 'DAY'
;
NUMBER : ('-')? DIGIT+ ('.' DIGIT+)? ;
ID : LETTER (NAME+) ;
QUOTEDTEXT : '"' .*? '"' ;
WHITESPACE : ' ' -> channel(HIDDEN);
Even like this the parsing doesn't pick up on the issue and returns only the first part of the query.
To summarize, when I feed the parser SUM(column1) SUM(column2) I would like it to return an error because it doesn't have any associated rule for that case.
Don't know what I am missing. Thanks for any direction.

Answer 1

Augment the grammar with "expr_prime : expression EOF;", and remove the EOF from the argument_list rule. Start parsing with expr_prime().