Define SqlKind for DIVIDE and MOD UDF for coercion purpose

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

core/src/main/java/org/opensearch/sql/expression/function/UserDefinedFunctionBuilder.java

@@ -33,6 +33,10 @@ public interface UserDefinedFunctionBuilder {
 
   UDFOperandMetadata getOperandMetadata();
 
+  default SqlKind getKind() {
+    return SqlKind.OTHER_FUNCTION;
+  }
+
   default SqlUserDefinedFunction toUDF(String functionName) {
     return toUDF(functionName, true);
   }
@@ -51,7 +55,7 @@ default SqlUserDefinedFunction toUDF(String functionName, boolean isDeterministi
         new SqlIdentifier(Collections.singletonList(functionName), null, SqlParserPos.ZERO, null);
     return new SqlUserDefinedFunction(
         udfLtrimIdentifier,
-        SqlKind.OTHER_FUNCTION,
+        getKind(),
         getReturnTypeInference(),
         InferTypes.ANY_NULLABLE,
         getOperandMetadata(),

core/src/main/java/org/opensearch/sql/expression/function/udf/math/DivideFunction.java

@@ -15,6 +15,7 @@
 import org.apache.calcite.linq4j.tree.Expressions;
 import org.apache.calcite.rel.type.RelDataTypeSystem;
 import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.sql.SqlKind;
 import org.apache.calcite.sql.type.ReturnTypes;
 import org.apache.calcite.sql.type.SqlReturnTypeInference;
 import org.apache.calcite.sql.type.SqlTypeName;
@@ -41,6 +42,11 @@ public DivideFunction() {
     super(new DivideImplementor(), NullPolicy.ANY);
   }
 
+  @Override
+  public SqlKind getKind() {
+    return SqlKind.DIVIDE;
+  }
+
   @Override
   public SqlReturnTypeInference getReturnTypeInference() {
     return ReturnTypes.QUOTIENT_FORCE_NULLABLE;

core/src/main/java/org/opensearch/sql/expression/function/udf/math/ModFunction.java

@@ -14,6 +14,7 @@
 import org.apache.calcite.linq4j.tree.Expressions;
 import org.apache.calcite.rel.type.RelDataType;
 import org.apache.calcite.rex.RexCall;
+import org.apache.calcite.sql.SqlKind;
 import org.apache.calcite.sql.type.ReturnTypes;
 import org.apache.calcite.sql.type.SqlReturnTypeInference;
 import org.apache.calcite.sql.type.SqlTypeFamily;
@@ -36,6 +37,11 @@ public SqlReturnTypeInference getReturnTypeInference() {
     return ReturnTypes.LEAST_RESTRICTIVE.andThen(SqlTypeTransforms.FORCE_NULLABLE);
   }
 
+  @Override
+  public SqlKind getKind() {
+    return SqlKind.MOD;
+  }
+
   @Override
   public UDFOperandMetadata getOperandMetadata() {
     return PPLOperandTypes.NUMERIC_NUMERIC;