How to do Priority of Operations (+ * - /) in my grammars? - antlr4

Question

I define my own grammars using antlr 4 and I want to build tree true According to Priority of Operations (+ * - /) ....
I find sample on do Priority of Operations (* +) it work fine ...
I try to edit it to add the Priority of Operations (- /) but I failed :(
the grammars for Priority of Operations (+ *) is :
println:PRINTLN expression SEMICOLON {System.out.println($expression.value);};
expression returns [Object value]:
t1=factor {$value=(int)$t1.value;}
(PLUS t2=factor{$value=(int)$value+(int)$t2.value;})*;
factor returns [Object value]: t1=term {$value=(int)$t1.value;}
(MULT t2=term{$value=(int)$value*(int)$t2.value;})*;
term returns [Object value]:
NUMBER {$value=Integer.parseInt($NUMBER.text);}
| ID {$value=symbolTable.get($value=$ID.text);}
| PAR_OPEN expression {$value=$expression.value;} PAR_CLOSE
;
MULT :'*';
PLUS :'+';
MINUS:'-';
DIV:'/' ;
How I can add to them the Priority of Operations (- /) ?

Answer 1

In ANTLR3 (and ANTLR4) * and / can be given a higher precedence than + and - like this:
println
: PRINTLN expression SEMICOLON
;
expression
: factor ( PLUS factor
| MINUS factor
)*
;
factor
: term ( MULT term
| DIV term
)*
;
term
: NUMBER
| ID
| PAR_OPEN expression PAR_CLOSE
;
But in ANTLR4, this will also work:
println
: PRINTLN expression SEMICOLON
;
expression
: NUMBER
| ID
| PAR_OPEN expression PAR_CLOSE
| expression ( MULT | DIV ) expression // higher precedence
| expression ( PLUS | MINUS ) expression // lower precedence
;

Answer 2

You normally solve this by defining expression, term, and factor production rules. Here's a grammar (specified in EBNF) that implements unary + and unary -, along with the 4 binary arithmetic operators, plus parentheses:
start ::= expression
expression ::= term (('+' term) | ('-' term))*
term ::= factor (('*' factor) | ('/' factor))*
factor :: = (number | group | '-' factor | '+' factor)
group ::= '(' expression ')'
where number is a numeric literal.