Constants on rest parameter nodes

Author: kddnewton

config.yml

@@ -2063,10 +2063,12 @@ nodes:
       `ex` is in the `exception` field.
   - name: RestParameterNode
     fields:
-      - name: operator_loc
-        type: location
+      - name: name
+        type: constant?
       - name: name_loc
         type: location?
+      - name: operator_loc
+        type: location
     comment: |
       Represents a rest parameter to a method, block, or lambda definition.
 

lib/yarp.rb

@@ -540,7 +540,7 @@ def self.yarp_locals(source)
             sorted = [
               *params.requireds.grep(RequiredParameterNode).map(&:name),
               *params.optionals.map(&:name),
-              *((params.rest.name ? params.rest.name.to_sym : :*) if params.rest && params.rest.operator != ","),
+              *((params.rest.name || :*) if params.rest && params.rest.operator != ","),
               *params.posts.grep(RequiredParameterNode).map(&:name),
               *params.keywords.reject(&:value).map(&:name),
               *params.keywords.select(&:value).map(&:name)

src/yarp.c

@@ -3904,8 +3904,9 @@ yp_rest_parameter_node_create(yp_parser_t *parser, const yp_token_t *operator, c
                 .end = (name->type == YP_TOKEN_NOT_PROVIDED ? operator->end : name->end)
             }
         },
-        .operator_loc = YP_LOCATION_TOKEN_VALUE(operator),
-        .name_loc = YP_OPTIONAL_LOCATION_TOKEN_VALUE(name)
+        .name = yp_parser_optional_constant_id_token(parser, name),
+        .name_loc = YP_OPTIONAL_LOCATION_TOKEN_VALUE(name),
+        .operator_loc = YP_LOCATION_TOKEN_VALUE(operator)
     };
 
     return node;

test/yarp/errors_test.rb

@@ -1051,7 +1051,7 @@ def test_duplicated_parameter_names
       expected = DefNode(
         Location(),
         nil,
-        ParametersNode([RequiredParameterNode(:a), RequiredParameterNode(:b)], [], [], RestParameterNode(Location(), Location()), [], nil, nil),
+        ParametersNode([RequiredParameterNode(:a), RequiredParameterNode(:b)], [], [], RestParameterNode(:a, Location(), Location()), [], nil, nil),
         nil,
         [:a, :b],
         Location(),
@@ -1105,7 +1105,7 @@ def test_duplicated_parameter_names
       expected = DefNode(
         Location(),
         nil,
-        ParametersNode([], [OptionalParameterNode(:a, Location(), Location(), IntegerNode())], [RequiredParameterNode(:b)], RestParameterNode(Location(), Location()), [], nil, nil),
+        ParametersNode([], [OptionalParameterNode(:a, Location(), Location(), IntegerNode())], [RequiredParameterNode(:b)], RestParameterNode(:c, Location(), Location()), [], nil, nil),
         nil,
         [:a, :b, :c],
         Location(),