Simplify the grammar to use just memberDeclaration

The spec_parser grammars have previously made a distinction among the
different kinds of members that a class, mixin, extension type, etc
could have. This is not very useful, though, so this CL changes the
grammar such that they all just contain a sequence of general member
declarations `<memberDeclaration>`. It is then up to non-parser based
error checks to prevent whatever should not exist (e.g., until we add
constructors to extensions it is an error to declare a constructor in
an `extension`, but this will be an ad-hoc check rather than a syntax
error).

Change-Id: Ifca2713af86eb3f569732ebef844135b772a5465
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/454280
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>

tools/spec_parser/Dart.g

@@ -4,6 +4,8 @@
 
 // CHANGES:
 //
+// v0.54 Simplify members.
+//
 // v0.53 Support declaring constructors.
 //
 // v0.52 Support static access shorthands.
@@ -435,7 +437,7 @@ classNamePart
     ;
 
 classBody
-    :    LBRACE (metadata classMemberDeclaration)* RBRACE
+    :    LBRACE (metadata memberDeclaration)* RBRACE
     |    ';'
     ;
 
@@ -461,7 +463,7 @@ interfaces
     :    IMPLEMENTS typeNotVoidNotFunctionList
     ;
 
-classMemberDeclaration
+memberDeclaration
     :    AUGMENT? methodSignature functionBody
     |    AUGMENT? declaration ';'
     ;
@@ -473,11 +475,7 @@ mixinApplicationClass
 mixinDeclaration
     :    AUGMENT? BASE? MIXIN typeWithParameters
          (ON typeNotVoidNotFunctionList)? interfaces?
-         LBRACE (metadata mixinMemberDeclaration)* RBRACE
-    ;
-
-mixinMemberDeclaration
-    :    classMemberDeclaration
+         LBRACE (metadata memberDeclaration)* RBRACE
     ;
 
 extensionTypeDeclaration
@@ -487,25 +485,17 @@ extensionTypeDeclaration
     ;
 
 extensionTypeBody
-    :    LBRACE (metadata extensionTypeMemberDeclaration)* RBRACE
+    :    LBRACE (metadata memberDeclaration)* RBRACE
     |    ';'
     ;
 
-extensionTypeMemberDeclaration
-    :    classMemberDeclaration
-    ;
-
 extensionDeclaration
     :    EXTENSION typeIdentifierNotType? typeParameters? ON type extensionBody
     |    AUGMENT EXTENSION typeIdentifierNotType typeParameters? extensionBody
     ;
 
 extensionBody
-    :    LBRACE (metadata extensionMemberDeclaration)* RBRACE
-    ;
-
-extensionMemberDeclaration
-    :    classMemberDeclaration
+    :    LBRACE (metadata memberDeclaration)* RBRACE
     ;
 
 methodSignature
@@ -697,7 +687,7 @@ mixinApplication
 enumType
     :    AUGMENT? ENUM classNamePart mixins? interfaces? LBRACE
          enumEntry (',' enumEntry)* ','?
-         (';' (metadata classMemberDeclaration)*)?
+         (';' (metadata memberDeclaration)*)?
          RBRACE
     ;
 

tools/spec_parser/dart_spec_parser/Dart.g4

@@ -4,6 +4,8 @@
 
 // CHANGES:
 //
+// v0.55 Simplify members.
+//
 // v0.54 Support declaring constructors.
 //
 // v0.53 Support static access shorthands.
@@ -445,7 +447,7 @@ classNamePart
     ;
 
 classBody
-    :    LBRACE (metadata classMemberDeclaration)* RBRACE
+    :    LBRACE (metadata memberDeclaration)* RBRACE
     |    ';'
     ;
 
@@ -471,7 +473,7 @@ interfaces
     :    IMPLEMENTS typeNotVoidNotFunctionList
     ;
 
-classMemberDeclaration
+memberDeclaration
     :    AUGMENT? methodSignature functionBody
     |    AUGMENT? declaration ';'
     ;
@@ -483,11 +485,7 @@ mixinApplicationClass
 mixinDeclaration
     :    AUGMENT? BASE? MIXIN typeWithParameters
          (ON typeNotVoidNotFunctionList)? interfaces?
-         LBRACE (metadata mixinMemberDeclaration)* RBRACE
-    ;
-
-mixinMemberDeclaration
-    :    classMemberDeclaration
+         LBRACE (metadata memberDeclaration)* RBRACE
     ;
 
 extensionTypeDeclaration
@@ -497,26 +495,17 @@ extensionTypeDeclaration
     ;
 
 extensionTypeBody
-    :    LBRACE (metadata extensionTypeMemberDeclaration)* RBRACE
+    :    LBRACE (metadata memberDeclaration)* RBRACE
     |    ';'
     ;
 
-extensionTypeMemberDeclaration
-    :    classMemberDeclaration
-    ;
-
 extensionDeclaration
     :    EXTENSION typeIdentifierNotType? typeParameters? ON type extensionBody
     |    AUGMENT EXTENSION typeIdentifierNotType typeParameters? extensionBody
     ;
 
 extensionBody
-    :    LBRACE (metadata extensionMemberDeclaration)* RBRACE
-    ;
-
-// TODO: We might want to make this more strict.
-extensionMemberDeclaration
-    :    classMemberDeclaration
+    :    LBRACE (metadata memberDeclaration)* RBRACE
     ;
 
 methodSignature
@@ -708,7 +697,7 @@ mixinApplication
 enumType
     :    AUGMENT? ENUM classNamePart mixins? interfaces? LBRACE
          enumEntry (',' enumEntry)* ','?
-         (';' (metadata classMemberDeclaration)*)?
+         (';' (metadata memberDeclaration)*)?
          RBRACE
     ;