From ab0deae0ef94a7ae7787cd836f66d593694fe92f Mon Sep 17 00:00:00 2001
From: Chen Dai <daichen@amazon.com>
Date: Wed, 14 Dec 2022 09:26:51 -0800
Subject: [PATCH] Fix precedence by reordering grammar rule

Signed-off-by: Chen Dai <daichen@amazon.com>
---
 sql/src/main/antlr/OpenSearchSQLParser.g4             |  9 ++++-----
 .../sql/sql/parser/AstExpressionBuilder.java          |  2 +-
 .../sql/sql/parser/AstExpressionBuilderTest.java      | 11 +++++++++++
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/sql/src/main/antlr/OpenSearchSQLParser.g4 b/sql/src/main/antlr/OpenSearchSQLParser.g4
index 58d4be1813..e24d38e093 100644
--- a/sql/src/main/antlr/OpenSearchSQLParser.g4
+++ b/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
diff --git a/sql/src/main/java/org/opensearch/sql/sql/parser/AstExpressionBuilder.java b/sql/src/main/java/org/opensearch/sql/sql/parser/AstExpressionBuilder.java
index bae22595ca..4b1a15425c 100644
--- a/sql/src/main/java/org/opensearch/sql/sql/parser/AstExpressionBuilder.java
+++ b/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))
     );
   }
diff --git a/sql/src/test/java/org/opensearch/sql/sql/parser/AstExpressionBuilderTest.java b/sql/src/test/java/org/opensearch/sql/sql/parser/AstExpressionBuilderTest.java
index 9af4119fdf..384e8765d9 100644
--- a/sql/src/test/java/org/opensearch/sql/sql/parser/AstExpressionBuilderTest.java
+++ b/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(