Parse optional and named parameters.

I'm not a big fan of the currentParameterKind stack, this information is
almost accessible from parseFormalParameter(), but we don't pass the type
to the listener.

R=ahe@google.com, paulberry@google.com
BUG=

Review-Url: https://codereview.chromium.org/2709783003 .

pkg/analyzer/test/generated/parser_fasta_test.dart

@@ -333,20 +333,19 @@ class FastaParserTestCase extends Object
   @override
   FormalParameter parseFormalParameter(String code, ParameterKind kind,
       {List<ErrorCode> errorCodes: const <ErrorCode>[]}) {
-    fasta.FormalParameterType type;
+    String parametersCode;
     if (kind == ParameterKind.REQUIRED) {
-      type = fasta.FormalParameterType.REQUIRED;
+      parametersCode = '($code)';
     } else if (kind == ParameterKind.POSITIONAL) {
-      type = fasta.FormalParameterType.POSITIONAL;
+      parametersCode = '([$code])';
     } else if (kind == ParameterKind.NAMED) {
-      type = fasta.FormalParameterType.NAMED;
+      parametersCode = '({$code})';
     } else {
       fail('$kind');
     }
-    return _runParser(
-        code,
-        (parser) => (token) => parser.parseFormalParameter(token, type),
-        errorCodes) as FormalParameter;
+    FormalParameterList list = parseFormalParameterList(parametersCode,
+        inFunctionType: false, errorCodes: errorCodes);
+    return list.parameters.single;
   }
 
   @override
@@ -496,34 +495,6 @@ class FormalParameterParserTest_Fasta extends FastaParserTestCase
     super.test_parseFormalParameter_covariant_var_positional();
   }
 
-  @override
-  @failingTest
-  void test_parseFormalParameter_final_named() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_final_named();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_final_positional() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_final_positional();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_final_type_named() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_final_type_named();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_final_type_positional() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_final_type_positional();
-  }
-
   @override
   @failingTest
   void test_parseFormalParameter_type_function() {
@@ -531,34 +502,6 @@ class FormalParameterParserTest_Fasta extends FastaParserTestCase
     super.test_parseFormalParameter_type_function();
   }
 
-  @override
-  @failingTest
-  void test_parseFormalParameter_type_named() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_type_named();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_type_positional() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_type_positional();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_var_named() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_var_named();
-  }
-
-  @override
-  @failingTest
-  void test_parseFormalParameter_var_positional() {
-    // TODO(scheglov): Unhandled event: ValuedFormalParameter
-    super.test_parseFormalParameter_var_positional();
-  }
-
   @override
   @failingTest
   void test_parseFormalParameterList_named_multiple() {

pkg/compiler/lib/src/parser/node_listener.dart

@@ -6,6 +6,8 @@ library dart2js.parser.node_listener;
 
 import '../common.dart';
 import '../elements/elements.dart' show CompilationUnitElement;
+import 'package:front_end/src/fasta/parser/parser.dart'
+    show FormalParameterType;
 import 'package:front_end/src/fasta/scanner/precedence.dart' as Precedence
     show INDEX_INFO;
 import 'package:front_end/src/fasta/scanner.dart' show StringToken, Token;
@@ -229,7 +231,7 @@ class NodeListener extends ElementListener {
   }
 
   @override
-  void endFormalParameter(Token thisKeyword) {
+  void endFormalParameter(Token thisKeyword, FormalParameterType kind) {
     Expression name = popNode();
     if (thisKeyword != null) {
       Identifier thisIdentifier = new Identifier(thisKeyword);
@@ -769,6 +771,10 @@ class NodeListener extends ElementListener {
         new NodeList.singleton(defaultValue)));
   }
 
+  @override
+  void handleFormalParameterWithoutValue(Token token) {
+  }
+
   @override
   void endTryStatement(int catchCount, Token tryKeyword, Token finallyKeyword) {
     Block finallyBlock = null;

pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart

@@ -9,6 +9,8 @@ import 'package:analyzer/dart/ast/ast_factory.dart' show AstFactory;
 import 'package:analyzer/dart/ast/standard_ast_factory.dart' as standard;
 import 'package:analyzer/dart/ast/token.dart' as analyzer show Token;
 import 'package:analyzer/dart/element/element.dart' show Element;
+import 'package:front_end/src/fasta/parser/parser.dart'
+    show FormalParameterType;
 import 'package:front_end/src/fasta/scanner/token.dart'
     show BeginGroupToken, Token;
 import 'package:kernel/ast.dart' show AsyncMarker;
@@ -42,6 +44,11 @@ class AstBuilder extends ScopeListener {
   @override
   final Uri uri;
 
+  /// If `true`, the first call to [handleIdentifier] should push a
+  /// List<SimpleIdentifier> on the stack, and [handleQualified] should append
+  /// to the list.
+  var accumulateIdentifierComponents = false;
+
   AstBuilder(this.library, this.member, this.elementStore, Scope scope,
       [Uri uri])
       : uri = uri ?? library.fileUri,
@@ -470,8 +477,26 @@ class AstBuilder extends ScopeListener {
     push(ast.throwExpression(toAnalyzerToken(throwToken), pop()));
   }
 
-  void endFormalParameter(Token thisKeyword) {
+  @override
+  void endOptionalFormalParameters(
+      int count, Token beginToken, Token endToken) {
+    debugEvent("OptionalFormalParameters");
+  }
+
+  void handleValuedFormalParameter(Token equals, Token token) {
+    debugEvent("ValuedFormalParameter");
+    Expression value = pop();
+    push(new _ParameterDefaultValue(equals, value));
+  }
+
+  void handleFormalParameterWithoutValue(Token token) {
+    debugEvent("FormalParameterWithoutValue");
+    push(NullValue.ParameterDefaultValue);
+  }
+
+  void endFormalParameter(Token thisKeyword, FormalParameterType kind) {
     debugEvent("FormalParameter");
+    _ParameterDefaultValue defaultValue = pop();
     SimpleIdentifier name = pop();
     TypeName type = pop();
     Token keyword = _popOptionalSingleModifier();
@@ -501,6 +526,11 @@ class AstBuilder extends ScopeListener {
           formalParameters);
     }
 
+    if (defaultValue != null) {
+      node = ast.defaultFormalParameter(node, _toAnalyzerParameterKind(kind),
+          toAnalyzerToken(defaultValue.separator), defaultValue.value);
+    }
+
     scope[name.name] = name.staticElement = new AnalyzerParameterElement(node);
     push(node);
   }
@@ -1177,6 +1207,16 @@ class AstBuilder extends ScopeListener {
       return null;
     }
   }
+
+  ParameterKind _toAnalyzerParameterKind(FormalParameterType type) {
+    if (type == FormalParameterType.POSITIONAL) {
+      return ParameterKind.POSITIONAL;
+    } else if (type == FormalParameterType.NAMED) {
+      return ParameterKind.NAMED;
+    } else {
+      return ParameterKind.REQUIRED;
+    }
+  }
 }
 
 /// Data structure placed on the stack to represent a class body.
@@ -1209,3 +1249,12 @@ class _MixinApplication {
 
   _MixinApplication(this.supertype, this.withKeyword, this.mixinTypes);
 }
+
+/// Data structure placed on the stack to represent the default parameter
+/// value with the separator token.
+class _ParameterDefaultValue {
+  final Token separator;
+  final Expression value;
+
+  _ParameterDefaultValue(this.separator, this.value);
+}

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

@@ -1277,7 +1277,7 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
   }
 
   @override
-  void endFormalParameter(Token thisKeyword) {
+  void endFormalParameter(Token thisKeyword, FormalParameterType kind) {
     debugEvent("FormalParameter");
     // TODO(ahe): Need beginToken here.
     int charOffset = thisKeyword?.charOffset;
@@ -1363,6 +1363,11 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
     push(new InitializedIdentifier(name.name, initializer));
   }
 
+  @override
+  void handleFormalParameterWithoutValue(Token token) {
+    debugEvent("FormalParameterWithoutValue");
+  }
+
   @override
   void endFormalParameters(int count, Token beginToken, Token endToken) {
     debugEvent("FormalParameters");

pkg/front_end/lib/src/fasta/parser/listener.dart

@@ -9,6 +9,7 @@ import '../scanner/token.dart' show BeginGroupToken, Token;
 import '../util/link.dart' show Link;
 
 import 'error_kind.dart' show ErrorKind;
+import 'parser.dart' show FormalParameterType;
 
 import 'identifier_context.dart' show IdentifierContext;
 
@@ -163,7 +164,7 @@ class Listener {
 
   void beginFormalParameter(Token token) {}
 
-  void endFormalParameter(Token thisKeyword) {
+  void endFormalParameter(Token thisKeyword, FormalParameterType kind) {
     logEvent("FormalParameter");
   }
 
@@ -901,6 +902,10 @@ class Listener {
     logEvent("ValuedFormalParameter");
   }
 
+  void handleFormalParameterWithoutValue(Token token) {
+    logEvent("FormalParameterWithoutValue");
+  }
+
   void handleVoidKeyword(Token token) {
     logEvent("VoidKeyword");
   }

pkg/front_end/lib/src/fasta/parser/parser.dart

@@ -490,7 +490,7 @@ class Parser {
     return expect(')', token);
   }
 
-  Token parseFormalParameter(Token token, FormalParameterType type,
+  Token parseFormalParameter(Token token, FormalParameterType kind,
       {bool inFunctionType: false}) {
     token = parseMetadataStar(token, forParameter: true);
     listener.beginFormalParameter(token);
@@ -504,7 +504,7 @@ class Parser {
       token = token.next;
     }
     token = parseModifiers(token);
-    bool isNamedParameter = type == FormalParameterType.NAMED;
+    bool isNamedParameter = kind == FormalParameterType.NAMED;
 
     Token thisKeyword = null;
     if (inFunctionType && isNamedParameter) {
@@ -564,15 +564,17 @@ class Parser {
       Token equal = token;
       token = parseExpression(token.next);
       listener.handleValuedFormalParameter(equal, token);
-      if (type.isRequired) {
+      if (kind.isRequired) {
         reportRecoverableError(
             equal, ErrorKind.RequiredParameterWithDefault);
-      } else if (type.isPositional && identical(':', value)) {
+      } else if (kind.isPositional && identical(':', value)) {
         reportRecoverableError(
             equal, ErrorKind.PositionalParameterWithEquals);
       }
+    } else {
+      listener.handleFormalParameterWithoutValue(token);
     }
-    listener.endFormalParameter(thisKeyword);
+    listener.endFormalParameter(thisKeyword, kind);
     return token;
   }
 

pkg/front_end/lib/src/fasta/source/outline_builder.dart

@@ -372,7 +372,7 @@ class OutlineBuilder extends UnhandledListener {
   }
 
   @override
-  void endFormalParameter(Token thisKeyword) {
+  void endFormalParameter(Token thisKeyword, FormalParameterType kind) {
     debugEvent("FormalParameter");
     String name = pop();
     TypeBuilder type = pop();
@@ -389,6 +389,12 @@ class OutlineBuilder extends UnhandledListener {
     // Ignored for now.
   }
 
+  @override
+  void handleFormalParameterWithoutValue(Token token) {
+    debugEvent("FormalParameterWithoutValue");
+    // Ignored for now.
+  }
+
   @override
   void endFunctionTypedFormalParameter(Token token) {
     debugEvent("FunctionTypedFormalParameter");

pkg/front_end/lib/src/fasta/source/stack_listener.dart

@@ -35,6 +35,7 @@ enum NullValue {
   Initializers,
   Metadata,
   Modifiers,
+  ParameterDefaultValue,
   SwitchScope,
   Type,
   TypeArguments,