pkg/analysis_server/lib/src/utilities/change_builder_dart.dart - sdk.git - Git at Google

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 import 'dart:async';

 import 'package:analysis_server/plugin/protocol/protocol.dart' hide ElementKind;
 import 'package:analysis_server/src/provisional/edit/utilities/change_builder_core.dart';
 import 'package:analysis_server/src/provisional/edit/utilities/change_builder_dart.dart';
 import 'package:analysis_server/src/services/correction/name_suggestion.dart';
 import 'package:analysis_server/src/services/correction/util.dart';
 import 'package:analysis_server/src/utilities/change_builder_core.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';

 /**
  * A [ChangeBuilder] used to build changes in Dart files.
  */
 class DartChangeBuilderImpl extends ChangeBuilderImpl
     implements DartChangeBuilder {
   /**
    * The analysis driver in which the files being edited were analyzed.
    */
   final AnalysisDriver driver;

   /**
    * Initialize a newly created change builder.
    */
   DartChangeBuilderImpl(this.driver);

   @override
   Future<DartFileEditBuilderImpl> createFileEditBuilder(
       String path, int fileStamp) async {
     AnalysisResult result = await driver.getResult(path);
     return new DartFileEditBuilderImpl(this, path, fileStamp, result.unit);
   }
 }

 /**
  * An [EditBuilder] used to build edits in Dart files.
  */
 class DartEditBuilderImpl extends EditBuilderImpl implements DartEditBuilder {
   /**
    * A utility class used to help build the source code.
    */
   final CorrectionUtils utils;

   /**
    * Initialize a newly created builder to build a source edit.
    */
   DartEditBuilderImpl(
       DartFileEditBuilderImpl sourceFileEditBuilder, int offset, int length)
       : utils = sourceFileEditBuilder.utils,
         super(sourceFileEditBuilder, offset, length);

   DartFileEditBuilderImpl get dartFileEditBuilder => fileEditBuilder;

   @override
   void writeClassDeclaration(String name,
       {Iterable<DartType> interfaces,
       bool isAbstract: false,
       void memberWriter(),
       Iterable<DartType> mixins,
       String nameGroupName,
       DartType superclass}) {
     // TODO(brianwilkerson) Add support for type parameters, probably as a
     // parameterWriter parameter.
     // TODO(brianwilkerson) Add a superclassGroupName parameter.
     if (isAbstract) {
       write(Keyword.ABSTRACT.syntax);
       write(' ');
     }
     write('class ');
     if (nameGroupName == null) {
       write(name);
     } else {
       addLinkedEdit(DartEditBuilder.NAME_GROUP_ID, (LinkedEditBuilder builder) {
         write(name);
       });
     }
     if (superclass != null) {
       write(' extends ');
       writeType(superclass, groupName: DartEditBuilder.SUPERCLASS_GROUP_ID);
     } else if (mixins != null && mixins.isNotEmpty) {
       write(' extends Object ');
     }
     writeTypes(mixins, prefix: ' with ');
     writeTypes(interfaces, prefix: ' implements ');
     writeln(' {');
     if (memberWriter != null) {
       writeln();
       memberWriter();
       writeln();
     }
     write('}');
   }

   //@override
   void writeConstructorDeclaration(ClassElement classElement,
       {ArgumentList argumentList,
       SimpleIdentifier constructorName,
       bool isConst: false}) {
     // TODO(brianwilkerson) Clean up the API and add it to the public API.
     //
     // TODO(brianwilkerson) Support passing a list of final fields rather than
     // an argument list.
     if (isConst) {
       write(Keyword.CONST.syntax);
       write(' ');
     }
     write(classElement.name);
     write('.');
     if (constructorName != null) {
       addLinkedEdit(DartEditBuilder.NAME_GROUP_ID, (LinkedEditBuilder builder) {
         write(constructorName.name);
       });
       CompilationUnit unit = constructorName
           .getAncestor((AstNode node) => node is CompilationUnit);
       if (unit != null) {
         CompilationUnitElement element = unit.element;
         if (element != null) {
           String referenceFile = element.source.fullName;
           if (referenceFile == dartFileEditBuilder.fileEdit.file) {
             dartFileEditBuilder.addLinkedPosition(constructorName.offset,
                 constructorName.length, DartEditBuilder.NAME_GROUP_ID);
           }
         }
       }
     }
     if (argumentList != null) {
       writeParametersMatchingArguments(argumentList);
     } else {
       write('()');
     }
     writeln(' {');
     write('  }');
   }

   @override
   void writeFieldDeclaration(String name,
       {void initializerWriter(),
       bool isConst: false,
       bool isFinal: false,
       bool isStatic: false,
       String nameGroupName,
       DartType type,
       String typeGroupName}) {
     if (isStatic) {
       write(Keyword.STATIC.syntax);
       write(' ');
     }
     bool typeRequired = true;
     if (isConst) {
       write(Keyword.CONST.syntax);
       typeRequired = false;
     } else if (isFinal) {
       write(Keyword.FINAL.syntax);
       typeRequired = false;
     }
     if (type != null) {
       writeType(type, groupName: typeGroupName);
     } else if (typeRequired) {
       write(Keyword.VAR.syntax);
     }
     write(' ');
     if (nameGroupName != null) {
       addLinkedEdit(nameGroupName, (LinkedEditBuilder builder) {
         write(name);
       });
     } else {
       write(name);
     }
     if (initializerWriter != null) {
       write(' = ');
       initializerWriter();
     }
     write(';');
   }

   @override
   void writeGetterDeclaration(String name,
       {void bodyWriter(),
       bool isStatic: false,
       String nameGroupName,
       DartType returnType,
       String returnTypeGroupName}) {
     if (isStatic) {
       write(Keyword.STATIC.syntax);
       write(' ');
     }
     if (returnType != null) {
       writeType(returnType, groupName: returnTypeGroupName);
       write(' ');
     }
     write(Keyword.GET.syntax);
     write(' ');
     if (nameGroupName != null) {
       addLinkedEdit(nameGroupName, (LinkedEditBuilder builder) {
         write(name);
       });
     } else {
       write(name);
     }
     if (bodyWriter == null) {
       write(' => null;');
     } else {
       write(' ');
       bodyWriter();
     }
   }

   @override
   void writeOverrideOfInheritedMember(ExecutableElement member) {
     // prepare environment
     String prefix = utils.getIndent(1);
     // may be property
     String prefix2 = utils.getIndent(2);
     ElementKind elementKind = member.kind;
     bool isGetter = elementKind == ElementKind.GETTER;
     bool isSetter = elementKind == ElementKind.SETTER;
     bool isMethod = elementKind == ElementKind.METHOD;
     bool isOperator = isMethod && (member as MethodElement).isOperator;
     write(prefix);
     if (isGetter) {
       writeln('// TODO: implement ${member.displayName}');
       write(prefix);
     }
     // @override
     writeln('@override');
     write(prefix);
     // return type
     // REVIEW: Added groupId
     bool shouldReturn = writeType(member.type.returnType,
         groupName: DartEditBuilder.RETURN_TYPE_GROUP_ID);
     write(' ');
     if (isGetter) {
       write(Keyword.GET.syntax);
       write(' ');
     } else if (isSetter) {
       write(Keyword.SET.syntax);
       write(' ');
     } else if (isOperator) {
       write(Keyword.OPERATOR.syntax);
       write(' ');
     }
     // name
     write(member.displayName);
     // parameters + body
     if (isGetter) {
       writeln(' => null;');
     } else {
       List<ParameterElement> parameters = member.parameters;
       writeParameters(parameters);
       writeln(' {');
       // TO-DO
       write(prefix2);
       writeln('// TODO: implement ${member.displayName}');
       // REVIEW: Added return statement.
       if (shouldReturn) {
         write(prefix2);
         writeln('return null;');
       }
       // close method
       write(prefix);
       writeln('}');
     }
   }

   @override
   void writeParameters(Iterable<ParameterElement> parameters) {
     write('(');
     bool sawNamed = false;
     bool sawPositional = false;
     for (int i = 0; i < parameters.length; i++) {
       ParameterElement parameter = parameters.elementAt(i);
       if (i > 0) {
         write(', ');
       }
       // may be optional
       ParameterKind parameterKind = parameter.parameterKind;
       if (parameterKind == ParameterKind.NAMED) {
         if (!sawNamed) {
           write('{');
           sawNamed = true;
         }
       }
       if (parameterKind == ParameterKind.POSITIONAL) {
         if (!sawPositional) {
           write('[');
           sawPositional = true;
         }
       }
       // parameter
       writeParameterSource(parameter.type, parameter.name);
       // default value
       String defaultCode = parameter.defaultValueCode;
       if (defaultCode != null) {
         if (sawPositional) {
           write(' = ');
         } else {
           write(': ');
         }
         write(defaultCode);
       }
     }
     // close parameters
     if (sawNamed) {
       write('}');
     }
     if (sawPositional) {
       write(']');
     }
     write(')');
   }

   @override
   void writeParametersMatchingArguments(ArgumentList arguments) {
     Set<String> excluded = new Set();
     bool namedFound = false;
     write('(');
     List<Expression> argumentList = arguments.arguments;
     for (int i = 0; i < argumentList.length; i++) {
       Expression argument = argumentList[i];
       DartType type = argument.bestType;
       List<String> suggestions =
           _getParameterNameSuggestions(excluded, type, argument, i);
       String favorite = suggestions[0];
       // append separator
       if (i > 0) {
         write(', ');
       }
       if (argument is NamedExpression) {
         if (!namedFound) {
           namedFound = true;
           write('[');
         }
         favorite = argument.name.label.name;
       }
       // append type name
       writeType(type, addSupertypeProposals: true, groupName: 'TYPE$i');
       write(' ');
       // append parameter name
       excluded.add(favorite);
       addLinkedEdit('ARG$i', (LinkedEditBuilder builder) {
         builder.write(favorite);
         builder.addSuggestions(LinkedEditSuggestionKind.PARAMETER, suggestions);
       });
     }
     if (namedFound) {
       write(']');
     }
     write(')');
   }

   @override
   void writeParameterSource(DartType type, String name) {
     String parameterSource = utils.getParameterSource(
         type, name, dartFileEditBuilder.librariesToImport);
     write(parameterSource);
   }

   @override
   bool writeType(DartType type,
       {bool addSupertypeProposals: false,
       String groupName,
       bool required: false}) {
     if (type != null && !type.isDynamic) {
       String typeSource =
           utils.getTypeSource(type, dartFileEditBuilder.librariesToImport);
       if (groupName != null) {
         addLinkedEdit(groupName, (LinkedEditBuilder builder) {
           write(typeSource);
           if (addSupertypeProposals) {
             _addSuperTypeProposals(builder, type, new Set<DartType>());
           }
         });
       } else {
         write(typeSource);
       }
       return true;
     } else if (required) {
       write(Keyword.VAR.syntax);
     }
     return false;
   }

   /**
    * Write the code for a comma-separated list of [types], optionally prefixed
    * by a [prefix]. If the list of [types] is `null` or does not return any
    * types, then nothing will be written.
    */
   void writeTypes(Iterable<DartType> types, {String prefix}) {
     if (types == null || types.isEmpty) {
       return;
     }
     bool first = true;
     for (DartType type in types) {
       if (first) {
         if (prefix != null) {
           write(prefix);
         }
         first = false;
       } else {
         write(', ');
       }
       writeType(type);
     }
   }

   void _addSuperTypeProposals(
       LinkedEditBuilder builder, DartType type, Set<DartType> alreadyAdded) {
     if (type != null &&
         type.element is ClassElement &&
         alreadyAdded.add(type)) {
       ClassElement element = type.element as ClassElement;
       builder.addSuggestion(LinkedEditSuggestionKind.TYPE, element.name);
       _addSuperTypeProposals(builder, element.supertype, alreadyAdded);
       for (InterfaceType interfaceType in element.interfaces) {
         _addSuperTypeProposals(builder, interfaceType, alreadyAdded);
       }
     }
   }

   /**
    * Return a list containing the suggested names for a parmeter with the given
    * [type] whose value in one location is computed by the given [expression].
    * The list will not contain any names in the set of [excluded] names. The
    * [index] is the index of the argument, used to create a name if no better
    * name could be created. The first name in the list will be the best name.
    */
   List<String> _getParameterNameSuggestions(
       Set<String> excluded, DartType type, Expression expression, int index) {
     List<String> suggestions =
         getVariableNameSuggestionsForExpression(type, expression, excluded);
     if (suggestions.length != 0) {
       return suggestions;
     }
     return <String>['arg$index'];
   }
 }

 /**
  * A [FileEditBuilder] used to build edits for Dart files.
  */
 class DartFileEditBuilderImpl extends FileEditBuilderImpl
     implements DartFileEditBuilder {
   /**
    * The compilation unit to which the code will be added.
    */
   CompilationUnit unit;

   /**
    * A utility class used to help build the source code.
    */
   CorrectionUtils utils;

   /**
    * A set containing the sources of the libraries that need to be imported in
    * order to make visible the names used in generated code.
    */
   Set<Source> librariesToImport = new Set<Source>();

   /**
    * Initialize a newly created builder to build a source file edit within the
    * change being built by the given [changeBuilder]. The file being edited has
    * the given [source] and [timeStamp], and the given fully resolved [unit].
    */
   DartFileEditBuilderImpl(DartChangeBuilderImpl changeBuilder, String path,
       int timeStamp, this.unit)
       : super(changeBuilder, path, timeStamp) {
     utils = new CorrectionUtils(unit);
   }

   @override
   DartEditBuilderImpl createEditBuilder(int offset, int length) {
     return new DartEditBuilderImpl(this, offset, length);
   }
 }
	// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	import 'dart:async';

	import 'package:analysis_server/plugin/protocol/protocol.dart' hide ElementKind;
	import 'package:analysis_server/src/provisional/edit/utilities/change_builder_core.dart';
	import 'package:analysis_server/src/provisional/edit/utilities/change_builder_dart.dart';
	import 'package:analysis_server/src/services/correction/name_suggestion.dart';
	import 'package:analysis_server/src/services/correction/util.dart';
	import 'package:analysis_server/src/utilities/change_builder_core.dart';
	import 'package:analyzer/dart/ast/ast.dart';
	import 'package:analyzer/dart/ast/token.dart';
	import 'package:analyzer/dart/element/element.dart';
	import 'package:analyzer/dart/element/type.dart';
	import 'package:analyzer/src/dart/analysis/driver.dart';
	import 'package:analyzer/src/generated/source.dart';
	import 'package:analyzer/src/generated/utilities_dart.dart';

	/**
	* A [ChangeBuilder] used to build changes in Dart files.
	*/
	class DartChangeBuilderImpl extends ChangeBuilderImpl
	implements DartChangeBuilder {
	/**
	* The analysis driver in which the files being edited were analyzed.
	*/
	final AnalysisDriver driver;

	/**
	* Initialize a newly created change builder.
	*/
	DartChangeBuilderImpl(this.driver);

	@override
	Future<DartFileEditBuilderImpl> createFileEditBuilder(
	String path, int fileStamp) async {
	AnalysisResult result = await driver.getResult(path);
	return new DartFileEditBuilderImpl(this, path, fileStamp, result.unit);
	}
	}

	/**
	* An [EditBuilder] used to build edits in Dart files.
	*/
	class DartEditBuilderImpl extends EditBuilderImpl implements DartEditBuilder {
	/**
	* A utility class used to help build the source code.
	*/
	final CorrectionUtils utils;

	/**
	* Initialize a newly created builder to build a source edit.
	*/
	DartEditBuilderImpl(
	DartFileEditBuilderImpl sourceFileEditBuilder, int offset, int length)
	: utils = sourceFileEditBuilder.utils,
	super(sourceFileEditBuilder, offset, length);

	DartFileEditBuilderImpl get dartFileEditBuilder => fileEditBuilder;

	@override
	void writeClassDeclaration(String name,
	{Iterable<DartType> interfaces,
	bool isAbstract: false,
	void memberWriter(),
	Iterable<DartType> mixins,
	String nameGroupName,
	DartType superclass}) {
	// TODO(brianwilkerson) Add support for type parameters, probably as a
	// parameterWriter parameter.
	// TODO(brianwilkerson) Add a superclassGroupName parameter.
	if (isAbstract) {
	write(Keyword.ABSTRACT.syntax);
	write(' ');
	}
	write('class ');
	if (nameGroupName == null) {
	write(name);
	} else {
	addLinkedEdit(DartEditBuilder.NAME_GROUP_ID, (LinkedEditBuilder builder) {
	write(name);
	});
	}
	if (superclass != null) {
	write(' extends ');
	writeType(superclass, groupName: DartEditBuilder.SUPERCLASS_GROUP_ID);
	} else if (mixins != null && mixins.isNotEmpty) {
	write(' extends Object ');
	}
	writeTypes(mixins, prefix: ' with ');
	writeTypes(interfaces, prefix: ' implements ');
	writeln(' {');
	if (memberWriter != null) {
	writeln();
	memberWriter();
	writeln();
	}
	write('}');
	}

	//@override
	void writeConstructorDeclaration(ClassElement classElement,
	{ArgumentList argumentList,
	SimpleIdentifier constructorName,
	bool isConst: false}) {
	// TODO(brianwilkerson) Clean up the API and add it to the public API.
	//
	// TODO(brianwilkerson) Support passing a list of final fields rather than
	// an argument list.
	if (isConst) {
	write(Keyword.CONST.syntax);
	write(' ');
	}
	write(classElement.name);
	write('.');
	if (constructorName != null) {
	addLinkedEdit(DartEditBuilder.NAME_GROUP_ID, (LinkedEditBuilder builder) {
	write(constructorName.name);
	});
	CompilationUnit unit = constructorName
	.getAncestor((AstNode node) => node is CompilationUnit);
	if (unit != null) {
	CompilationUnitElement element = unit.element;
	if (element != null) {
	String referenceFile = element.source.fullName;
	if (referenceFile == dartFileEditBuilder.fileEdit.file) {
	dartFileEditBuilder.addLinkedPosition(constructorName.offset,
	constructorName.length, DartEditBuilder.NAME_GROUP_ID);
	}
	}
	}
	}
	if (argumentList != null) {
	writeParametersMatchingArguments(argumentList);
	} else {
	write('()');
	}
	writeln(' {');
	write(' }');
	}

	@override
	void writeFieldDeclaration(String name,
	{void initializerWriter(),
	bool isConst: false,
	bool isFinal: false,
	bool isStatic: false,
	String nameGroupName,
	DartType type,
	String typeGroupName}) {
	if (isStatic) {
	write(Keyword.STATIC.syntax);
	write(' ');
	}
	bool typeRequired = true;
	if (isConst) {
	write(Keyword.CONST.syntax);
	typeRequired = false;
	} else if (isFinal) {
	write(Keyword.FINAL.syntax);
	typeRequired = false;
	}
	if (type != null) {
	writeType(type, groupName: typeGroupName);
	} else if (typeRequired) {
	write(Keyword.VAR.syntax);
	}
	write(' ');
	if (nameGroupName != null) {
	addLinkedEdit(nameGroupName, (LinkedEditBuilder builder) {
	write(name);
	});
	} else {
	write(name);
	}
	if (initializerWriter != null) {
	write(' = ');
	initializerWriter();
	}
	write(';');
	}

	@override
	void writeGetterDeclaration(String name,
	{void bodyWriter(),
	bool isStatic: false,
	String nameGroupName,
	DartType returnType,
	String returnTypeGroupName}) {
	if (isStatic) {
	write(Keyword.STATIC.syntax);
	write(' ');
	}
	if (returnType != null) {
	writeType(returnType, groupName: returnTypeGroupName);
	write(' ');
	}
	write(Keyword.GET.syntax);
	write(' ');
	if (nameGroupName != null) {
	addLinkedEdit(nameGroupName, (LinkedEditBuilder builder) {
	write(name);
	});
	} else {
	write(name);
	}
	if (bodyWriter == null) {
	write(' => null;');
	} else {
	write(' ');
	bodyWriter();
	}
	}

	@override
	void writeOverrideOfInheritedMember(ExecutableElement member) {
	// prepare environment
	String prefix = utils.getIndent(1);
	// may be property
	String prefix2 = utils.getIndent(2);
	ElementKind elementKind = member.kind;
	bool isGetter = elementKind == ElementKind.GETTER;
	bool isSetter = elementKind == ElementKind.SETTER;
	bool isMethod = elementKind == ElementKind.METHOD;
	bool isOperator = isMethod && (member as MethodElement).isOperator;
	write(prefix);
	if (isGetter) {
	writeln('// TODO: implement ${member.displayName}');
	write(prefix);
	}
	// @override
	writeln('@override');
	write(prefix);
	// return type
	// REVIEW: Added groupId
	bool shouldReturn = writeType(member.type.returnType,
	groupName: DartEditBuilder.RETURN_TYPE_GROUP_ID);
	write(' ');
	if (isGetter) {
	write(Keyword.GET.syntax);
	write(' ');
	} else if (isSetter) {
	write(Keyword.SET.syntax);
	write(' ');
	} else if (isOperator) {
	write(Keyword.OPERATOR.syntax);
	write(' ');
	}
	// name
	write(member.displayName);
	// parameters + body
	if (isGetter) {
	writeln(' => null;');
	} else {
	List<ParameterElement> parameters = member.parameters;
	writeParameters(parameters);
	writeln(' {');
	// TO-DO
	write(prefix2);
	writeln('// TODO: implement ${member.displayName}');
	// REVIEW: Added return statement.
	if (shouldReturn) {
	write(prefix2);
	writeln('return null;');
	}
	// close method
	write(prefix);
	writeln('}');
	}
	}

	@override
	void writeParameters(Iterable<ParameterElement> parameters) {
	write('(');
	bool sawNamed = false;
	bool sawPositional = false;
	for (int i = 0; i < parameters.length; i++) {
	ParameterElement parameter = parameters.elementAt(i);
	if (i > 0) {
	write(', ');
	}
	// may be optional
	ParameterKind parameterKind = parameter.parameterKind;
	if (parameterKind == ParameterKind.NAMED) {
	if (!sawNamed) {
	write('{');
	sawNamed = true;
	}
	}
	if (parameterKind == ParameterKind.POSITIONAL) {
	if (!sawPositional) {
	write('[');
	sawPositional = true;
	}
	}
	// parameter
	writeParameterSource(parameter.type, parameter.name);
	// default value
	String defaultCode = parameter.defaultValueCode;
	if (defaultCode != null) {
	if (sawPositional) {
	write(' = ');
	} else {
	write(': ');
	}
	write(defaultCode);
	}
	}
	// close parameters
	if (sawNamed) {
	write('}');
	}
	if (sawPositional) {
	write(']');
	}
	write(')');
	}

	@override
	void writeParametersMatchingArguments(ArgumentList arguments) {
	Set<String> excluded = new Set();
	bool namedFound = false;
	write('(');
	List<Expression> argumentList = arguments.arguments;
	for (int i = 0; i < argumentList.length; i++) {
	Expression argument = argumentList[i];
	DartType type = argument.bestType;
	List<String> suggestions =
	_getParameterNameSuggestions(excluded, type, argument, i);
	String favorite = suggestions[0];
	// append separator
	if (i > 0) {
	write(', ');
	}
	if (argument is NamedExpression) {
	if (!namedFound) {
	namedFound = true;
	write('[');
	}
	favorite = argument.name.label.name;
	}
	// append type name
	writeType(type, addSupertypeProposals: true, groupName: 'TYPE$i');
	write(' ');
	// append parameter name
	excluded.add(favorite);
	addLinkedEdit('ARG$i', (LinkedEditBuilder builder) {
	builder.write(favorite);
	builder.addSuggestions(LinkedEditSuggestionKind.PARAMETER, suggestions);
	});
	}
	if (namedFound) {
	write(']');
	}
	write(')');
	}

	@override
	void writeParameterSource(DartType type, String name) {
	String parameterSource = utils.getParameterSource(
	type, name, dartFileEditBuilder.librariesToImport);
	write(parameterSource);
	}

	@override
	bool writeType(DartType type,
	{bool addSupertypeProposals: false,
	String groupName,
	bool required: false}) {
	if (type != null && !type.isDynamic) {
	String typeSource =
	utils.getTypeSource(type, dartFileEditBuilder.librariesToImport);
	if (groupName != null) {
	addLinkedEdit(groupName, (LinkedEditBuilder builder) {
	write(typeSource);
	if (addSupertypeProposals) {
	_addSuperTypeProposals(builder, type, new Set<DartType>());
	}
	});
	} else {
	write(typeSource);
	}
	return true;
	} else if (required) {
	write(Keyword.VAR.syntax);
	}
	return false;
	}

	/**
	* Write the code for a comma-separated list of [types], optionally prefixed
	* by a [prefix]. If the list of [types] is `null` or does not return any
	* types, then nothing will be written.
	*/
	void writeTypes(Iterable<DartType> types, {String prefix}) {
	if (types == null \|\| types.isEmpty) {
	return;
	}
	bool first = true;
	for (DartType type in types) {
	if (first) {
	if (prefix != null) {
	write(prefix);
	}
	first = false;
	} else {
	write(', ');
	}
	writeType(type);
	}
	}

	void _addSuperTypeProposals(
	LinkedEditBuilder builder, DartType type, Set<DartType> alreadyAdded) {
	if (type != null &&
	type.element is ClassElement &&
	alreadyAdded.add(type)) {
	ClassElement element = type.element as ClassElement;
	builder.addSuggestion(LinkedEditSuggestionKind.TYPE, element.name);
	_addSuperTypeProposals(builder, element.supertype, alreadyAdded);
	for (InterfaceType interfaceType in element.interfaces) {
	_addSuperTypeProposals(builder, interfaceType, alreadyAdded);
	}
	}
	}

	/**
	* Return a list containing the suggested names for a parmeter with the given
	* [type] whose value in one location is computed by the given [expression].
	* The list will not contain any names in the set of [excluded] names. The
	* [index] is the index of the argument, used to create a name if no better
	* name could be created. The first name in the list will be the best name.
	*/
	List<String> _getParameterNameSuggestions(
	Set<String> excluded, DartType type, Expression expression, int index) {
	List<String> suggestions =
	getVariableNameSuggestionsForExpression(type, expression, excluded);
	if (suggestions.length != 0) {
	return suggestions;
	}
	return <String>['arg$index'];
	}
	}

	/**
	* A [FileEditBuilder] used to build edits for Dart files.
	*/
	class DartFileEditBuilderImpl extends FileEditBuilderImpl
	implements DartFileEditBuilder {
	/**
	* The compilation unit to which the code will be added.
	*/
	CompilationUnit unit;

	/**
	* A utility class used to help build the source code.
	*/
	CorrectionUtils utils;

	/**
	* A set containing the sources of the libraries that need to be imported in
	* order to make visible the names used in generated code.
	*/
	Set<Source> librariesToImport = new Set<Source>();

	/**
	* Initialize a newly created builder to build a source file edit within the
	* change being built by the given [changeBuilder]. The file being edited has
	* the given [source] and [timeStamp], and the given fully resolved [unit].
	*/
	DartFileEditBuilderImpl(DartChangeBuilderImpl changeBuilder, String path,
	int timeStamp, this.unit)
	: super(changeBuilder, path, timeStamp) {
	utils = new CorrectionUtils(unit);
	}

	@override
	DartEditBuilderImpl createEditBuilder(int offset, int length) {
	return new DartEditBuilderImpl(this, offset, length);
	}
	}