Fix precedence by reordering grammar rule

Signed-off-by: Chen Dai <[email protected]>

Author: dai-chen

sql/src/main/antlr/OpenSearchSQLParser.g4

@@ -292,11 +292,10 @@ expressionAtom
     | columnName                                                    #fullColumnNameExpressionAtom
     | functionCall                                                  #functionCallExpressionAtom
     | LR_BRACKET expression RR_BRACKET                              #nestedExpressionAtom
-    | left=expressionAtom mathOperator right=expressionAtom         #mathExpressionAtom
-    ;
-
-mathOperator
-    : PLUS | MINUS | STAR | DIVIDE | MODULE
+    | left=expressionAtom mathOperator=(STAR | DIVIDE | MODULE)
+        right=expressionAtom                                        #mathExpressionAtom
+    | left=expressionAtom mathOperator=(PLUS | MINUS)
+        right=expressionAtom                                        #mathExpressionAtom
     ;
 
 comparisonOperator

sql/src/main/java/org/opensearch/sql/sql/parser/AstExpressionBuilder.java

@@ -120,7 +120,7 @@ public UnresolvedExpression visitQualifiedName(QualifiedNameContext ctx) {
   @Override
   public UnresolvedExpression visitMathExpressionAtom(MathExpressionAtomContext ctx) {
     return new Function(
-        ctx.mathOperator().getText(),
+        ctx.mathOperator.getText(),
         Arrays.asList(visit(ctx.left), visit(ctx.right))
     );
   }

sql/src/test/java/org/opensearch/sql/sql/parser/AstExpressionBuilderTest.java

@@ -153,6 +153,17 @@ public void canBuildArithmeticExpression() {
     );
   }
 
+  @Test
+  public void canBuildArithmeticExpressionWithPrecedence() {
+    assertEquals(
+        function("+",
+            intLiteral(1),
+            function("*",
+                intLiteral(2), intLiteral(3))),
+        buildExprAst("1 + 2 * 3")
+    );
+  }
+
   @Test
   public void canBuildFunctionWithoutArguments() {
     assertEquals(