Added support of timestamp/date/time using curly brackets

docs/user/dql/expressions.rst

@@ -25,7 +25,7 @@ A literal is a symbol that represents a value. The most common literal values in
 1. Numeric literals: specify numeric values such as integer and floating-point numbers.
 2. String literals: specify a string enclosed by single or double quotes.
 3. Boolean literals: ``true`` or ``false``.
-4. Date and Time literals: DATE 'YYYY-MM-DD' represent the date, TIME 'hh:mm:ss' represent the time, TIMESTAMP 'YYYY-MM-DD hh:mm:ss' represent the timestamp.
+4. Date and Time literals: DATE 'YYYY-MM-DD' represent the date, TIME 'hh:mm:ss' represent the time, TIMESTAMP 'YYYY-MM-DD hh:mm:ss' represent the timestamp. You can also surround the literals with curly brackets, if you do, you can replace date with d, time with t, and timestamp with ts
 
 Examples
 --------
@@ -49,6 +49,15 @@ Here is an example for different type of literals::
     | Hello     | Hello     | It"s      | It's      | It's     | "Its"     | It's      | It\'s       | \I\t\s     |
     +-----------+-----------+-----------+-----------+----------+-----------+-----------+-------------+------------+
 
+
+    os> SELECT {DATE '2020-07-07'}, {D '2020-07-07'}, {TIME '01:01:01'}, {T '01:01:01'}, {TIMESTAMP '2020-07-07 01:01:01'}, {TS '2020-07-07 01:01:01'}
+    fetched rows / total rows = 1/1
+    +-----------------------+--------------------+---------------------+------------------+-------------------------------------+------------------------------+
+    | {DATE '2020-07-07'}   | {D '2020-07-07'}   | {TIME '01:01:01'}   | {T '01:01:01'}   | {TIMESTAMP '2020-07-07 01:01:01'}   | {TS '2020-07-07 01:01:01'}   |
+    |-----------------------+--------------------+---------------------+------------------+-------------------------------------+------------------------------|
+    | 2020-07-07            | 2020-07-07         | 01:01:01            | 01:01:01         | 2020-07-07 01:01:01                 | 2020-07-07 01:01:01          |
+    +-----------------------+--------------------+---------------------+------------------+-------------------------------------+------------------------------+
+
 Limitations
 -----------
 

integ-test/src/test/java/org/opensearch/sql/sql/DateTimeFunctionIT.java

@@ -1288,4 +1288,103 @@ protected JSONObject executeQuery(String query) throws IOException {
     Response response = client().performRequest(request);
     return new JSONObject(getResponseBody(response));
   }
+
+  @Test
+  public void testTimestampBracket() throws IOException {
+    JSONObject result = executeQuery("select {timestamp '2020-09-16 17:30:00'}");
+    verifySchema(result, schema("{timestamp '2020-09-16 17:30:00'}", null, "timestamp"));
+    verifyDataRows(result, rows("2020-09-16 17:30:00"));
+
+    result = executeQuery("select {ts '2020-09-16 17:30:00'}");
+    verifySchema(result, schema("{ts '2020-09-16 17:30:00'}", null, "timestamp"));
+    verifyDataRows(result, rows("2020-09-16 17:30:00"));
+
+    result = executeQuery("select {timestamp '2020-09-16 17:30:00.123'}");
+    verifySchema(result, schema("{timestamp '2020-09-16 17:30:00.123'}", null, "timestamp"));
+    verifyDataRows(result, rows("2020-09-16 17:30:00.123"));
+
+    result = executeQuery("select {ts '2020-09-16 17:30:00.123'}");
+    verifySchema(result, schema("{ts '2020-09-16 17:30:00.123'}", null, "timestamp"));
+    verifyDataRows(result, rows("2020-09-16 17:30:00.123"));
+  }
+
+  @Test
+  public void testTimeBracket() throws IOException {
+    JSONObject result = executeQuery("select {time '17:30:00'}");
+    verifySchema(result, schema("{time '17:30:00'}", null, "time"));
+    verifyDataRows(result, rows("17:30:00"));
+
+    result = executeQuery("select {t '17:30:00'}");
+    verifySchema(result, schema("{t '17:30:00'}", null, "time"));
+    verifyDataRows(result, rows("17:30:00"));
+
+    result = executeQuery("select {time '17:30:00'}");
+    verifySchema(result, schema("{time '17:30:00'}", null, "time"));
+    verifyDataRows(result, rows("17:30:00"));
+
+    result = executeQuery("select {t '17:30:00'}");
+    verifySchema(result, schema("{t '17:30:00'}", null, "time"));
+    verifyDataRows(result, rows("17:30:00"));
+  }
+
+  @Test
+  public void testDateBracket() throws IOException {
+    JSONObject result = executeQuery("select {date '2020-09-16'}");
+    verifySchema(result, schema("{date '2020-09-16'}", null, "date"));
+    verifyDataRows(result, rows("2020-09-16"));
+
+    result = executeQuery("select {d '2020-09-16'}");
+    verifySchema(result, schema("{d '2020-09-16'}", null, "date"));
+    verifyDataRows(result, rows("2020-09-16"));
+  }
+
+  private void compareBrackets(String query1, String query2, String datetime) throws IOException {
+    JSONObject result1 = executeQuery("select " + query1 + " '" + datetime + "'");
+    JSONObject result2 = executeQuery("select {" + query2 + " '" + datetime + "'}");
+
+    verifyDataRows(result1, rows(datetime));
+    verifyDataRows(result2, rows(datetime));
+  }
+
+  @Test
+  public void testBracketedEquivalent() throws IOException {
+    compareBrackets("timestamp", "timestamp", "2020-09-16 17:30:00");
+    compareBrackets("timestamp", "ts", "2020-09-16 17:30:00");
+    compareBrackets("timestamp", "timestamp", "2020-09-16 17:30:00.123");
+    compareBrackets("timestamp", "ts", "2020-09-16 17:30:00.123");
+    compareBrackets("date", "date", "2020-09-16");
+    compareBrackets("date", "d", "2020-09-16");
+    compareBrackets("time", "time", "17:30:00");
+    compareBrackets("time", "t", "17:30:00");
+  }
+
+  private void queryFails(String query) {
+    Request request = new Request("POST", QUERY_API_ENDPOINT);
+    request.setJsonEntity(String.format(Locale.ROOT, "{\n" + "  \"query\": \"%s\"\n" + "}", query));
+
+    RequestOptions.Builder restOptionsBuilder = RequestOptions.DEFAULT.toBuilder();
+    restOptionsBuilder.addHeader("Content-Type", "application/json");
+    request.setOptions(restOptionsBuilder);
+
+    boolean fails = false;
+
+    try {
+      client().performRequest(request);
+    } catch(Exception ignored) {
+      fails = true;
+    }
+
+    assertTrue(fails);
+  }
+
+  @Test
+  public void testBracketFails() {
+    queryFails("select {time 'failure'}");
+    queryFails("select {t 'failure'}");
+    queryFails("select {date 'failure'}");
+    queryFails("select {d 'failure'}");
+    queryFails("select {timestamp 'failure'}");
+    queryFails("select {ts 'failure'}");
+
+  }
 }

sql/src/main/antlr/OpenSearchSQLParser.g4

@@ -185,7 +185,6 @@ constant
     // Doesn't support the following types for now
     //| BIT_STRING
     //| NOT? nullLiteral=(NULL_LITERAL | NULL_SPEC_LITERAL)
-    //| LEFT_BRACE dateType=(D | T | TS | DATE | TIME | TIMESTAMP) stringLiteral RIGHT_BRACE
     ;
 
 decimalLiteral
@@ -227,14 +226,17 @@ datetimeLiteral
 
 dateLiteral
     : DATE date=stringLiteral
+    | LEFT_BRACE (DATE | D) date=stringLiteral RIGHT_BRACE
     ;
 
 timeLiteral
     : TIME time=stringLiteral
+    | LEFT_BRACE (TIME | T) time=stringLiteral RIGHT_BRACE
     ;
 
 timestampLiteral
     : TIMESTAMP timestamp=stringLiteral
+    | LEFT_BRACE (TIMESTAMP | TS) timestamp=stringLiteral RIGHT_BRACE
     ;
 
 // Actually, these constants are shortcuts to the corresponding functions

sql/src/test/java/org/opensearch/sql/common/antlr/SyntaxParserTestBase.java

@@ -1,13 +1,11 @@
 package org.opensearch.sql.common.antlr;
 
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
-import org.opensearch.sql.sql.antlr.SQLSyntaxParser;
 
 /**
  * A base class for tests for SQL or PPL parser.

sql/src/test/java/org/opensearch/sql/sql/antlr/BracketedTimestampTest.java

@@ -0,0 +1,35 @@
+package org.opensearch.sql.sql.antlr;
+
+import org.junit.jupiter.api.Test;
+
+public class BracketedTimestampTest extends SQLParserTest {
+  @Test
+  void date_shortened_test() {
+    acceptQuery("SELECT {d '2001-05-07'}");
+  }
+
+  @Test
+  void date_test() {
+    acceptQuery("SELECT {date '2001-05-07'}");
+  }
+
+  @Test
+  void time_shortened_test() {
+    acceptQuery("SELECT {t '10:11:12'}");
+  }
+
+  @Test
+  void time_test() {
+    acceptQuery("SELECT {time '10:11:12'}");
+  }
+
+  @Test
+  void timestamp_shortened_test() {
+    acceptQuery("SELECT {ts '2001-05-07 10:11:12'}");
+  }
+
+  @Test
+  void timestamp_test() {
+    acceptQuery("SELECT {timestamp '2001-05-07 10:11:12'}");
+  }
+}