(extension with aggregates): allow a single positional item

grammar.js

@@ -690,7 +690,7 @@ module.exports = grammar({
          '(',
          $.expression,
          reservedWord('with'),
-         $.record_component_association_list,
+         $._record_component_association_list_or_expression,
          ')',
       ),
       record_delta_aggregate: $ => seq(
@@ -698,7 +698,7 @@ module.exports = grammar({
          $.expression,
          reservedWord('with'),
          reservedWord('delta'),
-         $.record_component_association_list,
+         $._record_component_association_list_or_expression,
          ')',
       ),
       array_delta_aggregate: $ => choice(
@@ -730,7 +730,7 @@ module.exports = grammar({
       // *  expression, {expression_or_named}
       //    expression_or_named:: expression | choice => expression
       // *  named {, named}
-      record_component_association_list: $ => choice(
+      record_component_association_list: $ => choice(    // RM 4.3.1
          seq(
             reservedWord('null'),
             reservedWord('record'),
@@ -745,6 +745,15 @@ module.exports = grammar({
          ),
          comma_separated_list_of($._named_record_component_association),
       ),
+
+      // We have modified record_component_association_list to accept a
+      // minimum of two positional expressions. However, in extension
+      // aggregates it is valid to have just "(parent with value)"
+      _record_component_association_list_or_expression: $ => choice(
+         $.record_component_association_list,
+         $.expression,
+      ),
+
       _named_record_component_association: $ => seq(  // adapted from ARM 4.3.1
          $.component_choice_list,
          '=>',

src/grammar.json

@@ -3531,7 +3531,7 @@
         },
         {
           "type": "SYMBOL",
-          "name": "record_component_association_list"
+          "name": "_record_component_association_list_or_expression"
         },
         {
           "type": "STRING",
@@ -3584,7 +3584,7 @@
         },
         {
           "type": "SYMBOL",
-          "name": "record_component_association_list"
+          "name": "_record_component_association_list_or_expression"
         },
         {
           "type": "STRING",
@@ -3843,6 +3843,19 @@
         }
       ]
     },
+    "_record_component_association_list_or_expression": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "record_component_association_list"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "expression"
+        }
+      ]
+    },
     "_named_record_component_association": {
       "type": "SEQ",
       "members": [

test/corpus/records.txt

@@ -458,3 +458,52 @@ variants 2
                       (identifier)
                       (component_definition
                         (identifier)))))))))))))
+
+================================================================================
+Extension with aggregate
+================================================================================
+
+procedure Proc is
+   Null  : constant Rec := (Parent with A => null);
+   Null2 : constant Rec := (Parent with null);
+begin
+   null;
+end;
+
+--------------------------------------------------------------------------------
+
+(compilation
+  (compilation_unit
+    (subprogram_body
+      (procedure_specification
+        (identifier))
+      (non_empty_declarative_part
+        (object_declaration
+          (identifier)
+          (identifier)
+          (expression
+            (term
+              (extension_aggregate
+                (expression
+                  (term
+                    (identifier)))
+                (record_component_association_list
+                  (component_choice_list
+                    (identifier))
+                  (expression
+                    (term
+                      (primary_null))))))))
+        (object_declaration
+          (identifier)
+          (identifier)
+          (expression
+            (term
+              (extension_aggregate
+                (expression
+                  (term
+                    (identifier)))
+                (expression
+                  (term
+                    (primary_null))))))))
+      (handled_sequence_of_statements
+        (null_statement)))))