#963 Unimplemented PPL Sort Syntax

docs/ppl-lang/PPL-Example-Commands.md

@@ -274,7 +274,8 @@ source = table |  where ispresent(a) |
 - `source=accounts | parse email '.+@(?<host>.+)' | stats count() by host`
 - `source=accounts | parse email '.+@(?<host>.+)' | eval eval_result=1 | fields host, eval_result`
 - `source=accounts | parse email '.+@(?<host>.+)' | where age > 45 | sort - age | fields age, email, host`
-- `source=accounts | parse address '(?<streetNumber>\d+) (?<street>.+)' | where streetNumber > 500 | sort num(streetNumber) | fields streetNumber, street`
+- `source=accounts | parse address '(?<streetNumber>\d+) (?<street>.+)' | eval streetNumberInt = cast(streetNumber as integer) | where streetNumberInt > 500 | sort streetNumberInt | fields streetNumber, street`
+  - **Note**: The `sort num` syntax is not implemented. To sort numerically, cast to a numerical data type - e.g. `sort cast(streetNumber as integer)`. See [#963](https://github.com/opensearch-project/opensearch-spark/issues/963) for more details.
 - Limitation: [see limitations](ppl-parse-command.md#limitations)
 
 #### **Grok**

docs/ppl-lang/ppl-parse-command.md

@@ -58,7 +58,7 @@ The example shows how to sort street numbers that are higher than 500 in ``addre
 
 PPL query:
 
-    os> source=accounts | parse address '(?<streetNumber>\d+) (?<street>.+)' | where cast(streetNumber as int) > 500 | sort num(streetNumber) | fields streetNumber, street ;
+    os> source=accounts | parse address '(?<streetNumber>\d+) (?<street>.+)' | eval streetNumberInt = cast(streetNumber as integer) | where streetNumberInt > 500 | sort streetNumberInt | fields streetNumber, street ;
     fetched rows / total rows = 3/3
     +----------------+----------------+
     | streetNumber   | street         |
@@ -68,6 +68,8 @@ PPL query:
     | 880            | Holmes Lane    |
     +----------------+----------------+
 
+**Note**: The `sort num` syntax is not implemented. To sort numerically, cast to a numerical data type - e.g. `sort cast(streetNumber as integer)`. See [#963](https://github.com/opensearch-project/opensearch-spark/issues/963) for more details.
+
 ### Limitations
 
 There are a few limitations with parse command:

ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4

@@ -82,13 +82,13 @@ DATASOURCES:                        'DATASOURCES';
 USING:                              'USING';
 WITH:                               'WITH';
 
-// FIELD KEYWORDS
+// SORT FIELD KEYWORDS
+// TODO #963: Implement sort syntax
 AUTO:                               'AUTO';
 STR:                                'STR';
 IP:                                 'IP';
 NUM:                                'NUM';
 
-
 // FIELDSUMMARY keywords
 FIELDSUMMARY:                       'FIELDSUMMARY';
 INCLUDEFIELDS:                      'INCLUDEFIELDS';

ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4

@@ -520,6 +520,8 @@ sortField
 
 sortFieldExpression
    : fieldExpression
+
+   // TODO #963: Implement sort syntax
    | AUTO LT_PRTHS fieldExpression RT_PRTHS
    | STR LT_PRTHS fieldExpression RT_PRTHS
    | IP LT_PRTHS fieldExpression RT_PRTHS
@@ -1095,10 +1097,6 @@ keywordsCanBeId
    | INDEX
    | DESC
    | DATASOURCES
-   | AUTO
-   | STR
-   | IP
-   | NUM
    | FROM
    | PATTERN
    | NEW_FIELD
@@ -1181,4 +1179,9 @@ keywordsCanBeId
    | BETWEEN
    | CIDRMATCH
    | trendlineType
+   // SORT FIELD KEYWORDS
+   | AUTO
+   | STR
+   | IP
+   | NUM
    ;

ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstExpressionBuilder.java

@@ -45,8 +45,6 @@
 import org.opensearch.sql.ast.expression.subquery.ExistsSubquery;
 import org.opensearch.sql.ast.expression.subquery.InSubquery;
 import org.opensearch.sql.ast.expression.subquery.ScalarSubquery;
-import org.opensearch.sql.ast.tree.Trendline;
-import org.opensearch.sql.common.antlr.SyntaxCheckException;
 import org.opensearch.sql.common.utils.StringUtils;
 import org.opensearch.sql.ppl.utils.ArgumentFactory;
 
@@ -183,6 +181,8 @@ public UnresolvedExpression visitWcFieldExpression(OpenSearchPPLParser.WcFieldEx
 
     @Override
     public UnresolvedExpression visitSortField(OpenSearchPPLParser.SortFieldContext ctx) {
+
+        // TODO #963: Implement sort syntax
         return new Field((QualifiedName)
                 visit(ctx.sortFieldExpression().fieldExpression().qualifiedName()),
                 ArgumentFactory.getArgumentList(ctx));

ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanParseTranslatorTestSuite.scala

@@ -13,9 +13,10 @@ import org.scalatest.matchers.should.Matchers
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.catalyst.ScalaReflection.universe.Star
 import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute, UnresolvedFunction, UnresolvedRelation, UnresolvedStar}
-import org.apache.spark.sql.catalyst.expressions.{Alias, Ascending, Coalesce, Descending, GreaterThan, Literal, NamedExpression, NullsFirst, NullsLast, RegExpExtract, SortOrder}
+import org.apache.spark.sql.catalyst.expressions.{Alias, Ascending, Cast, Coalesce, Descending, GreaterThan, Literal, NamedExpression, NullsFirst, NullsLast, RegExpExtract, SortOrder}
 import org.apache.spark.sql.catalyst.plans.PlanTest
 import org.apache.spark.sql.catalyst.plans.logical.{Aggregate, Filter, GlobalLimit, LocalLimit, Project, Sort}
+import org.apache.spark.sql.types.IntegerType
 
 class PPLLogicalPlanParseTranslatorTestSuite
     extends SparkFunSuite
@@ -122,41 +123,47 @@ class PPLLogicalPlanParseTranslatorTestSuite
 
   test("test parse email & host expressions including cast and sort commands") {
     val context = new CatalystPlanContext
-    val logPlan =
-      planTransformer.visit(
-        plan(
-          pplParser,
-          "source=t | parse address '(?<streetNumber>\\d+) (?<street>.+)' | where streetNumber > 500 | sort num(streetNumber) | fields streetNumber, street"),
-        context)
+
+    // TODO #963: Implement sort syntax
+    val query =
+      "source=t" +
+        " | parse address '(?<streetNumber>\\d+) (?<street>.+)'" +
+        " | eval streetNumberInt = cast(streetNumber as integer)" +
+        " | where streetNumberInt > 500" +
+        " | sort streetNumberInt" +
+        " | fields streetNumber, street"
+
+    val logPlan = planTransformer.visit(plan(pplParser, query), context)
 
     val addressAttribute = UnresolvedAttribute("address")
     val streetNumberAttribute = UnresolvedAttribute("streetNumber")
     val streetAttribute = UnresolvedAttribute("street")
+    val streetNumberIntAttribute = UnresolvedAttribute("streetNumberInt")
 
-    val streetNumberExpression = Alias(
-      RegExpExtract(
-        addressAttribute,
-        Literal("(?<streetNumber>\\d+) (?<street>.+)"),
-        Literal("1")),
-      "streetNumber")()
+    val regexLiteral = Literal("(?<streetNumber>\\d+) (?<street>.+)")
+    val streetNumberExpression =
+      Alias(RegExpExtract(addressAttribute, regexLiteral, Literal("1")), "streetNumber")()
+    val streetExpression =
+      Alias(RegExpExtract(addressAttribute, regexLiteral, Literal("2")), "street")()
 
-    val streetExpression = Alias(
-      RegExpExtract(
-        addressAttribute,
-        Literal("(?<streetNumber>\\d+) (?<street>.+)"),
-        Literal("2")),
-      "street")()
+    val castExpression = Cast(streetNumberAttribute, IntegerType)
 
     val expectedPlan = Project(
       Seq(streetNumberAttribute, streetAttribute),
       Sort(
-        Seq(SortOrder(streetNumberAttribute, Ascending, NullsFirst, Seq.empty)),
+        Seq(SortOrder(streetNumberIntAttribute, Ascending, NullsFirst, Seq.empty)),
         global = true,
         Filter(
-          GreaterThan(streetNumberAttribute, Literal(500)),
+          GreaterThan(streetNumberIntAttribute, Literal(500)),
           Project(
-            Seq(addressAttribute, streetNumberExpression, streetExpression, UnresolvedStar(None)),
-            UnresolvedRelation(Seq("t"))))))
+            Seq(UnresolvedStar(None), Alias(castExpression, "streetNumberInt")()),
+            Project(
+              Seq(
+                addressAttribute,
+                streetNumberExpression,
+                streetExpression,
+                UnresolvedStar(None)),
+              UnresolvedRelation(Seq("t")))))))
 
     assert(compareByString(expectedPlan) === compareByString(logPlan))
   }