Elements. Remove FragmentOrMember.

Change-Id: I1d5470c8ffafff154d3c3da7f5834ec8c05697c4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/438262
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/element/element.dart

@@ -29,7 +29,6 @@ import 'package:analyzer/src/dart/constant/value.dart';
 import 'package:analyzer/src/dart/element/display_string_builder.dart';
 import 'package:analyzer/src/dart/element/field_name_non_promotability_info.dart';
 import 'package:analyzer/src/dart/element/inheritance_manager3.dart';
-import 'package:analyzer/src/dart/element/member.dart';
 import 'package:analyzer/src/dart/element/name_union.dart';
 import 'package:analyzer/src/dart/element/scope.dart';
 import 'package:analyzer/src/dart/element/since_sdk_version.dart';
@@ -1084,7 +1083,7 @@ class ConstructorFragmentImpl extends ExecutableFragmentImpl
   }
 
   @override
-  int get offset => isSynthetic ? enclosingElement3.offset : _nameOffset;
+  int get offset => isSynthetic ? enclosingElement3.offset : nameOffset;
 
   @override
   InterfaceTypeImpl get returnType {
@@ -2305,7 +2304,7 @@ abstract class ExecutableFragmentImpl extends _ExistingFragmentImpl
   }
 
   @override
-  int get offset => _nameOffset;
+  int get offset => nameOffset;
 
   /// The formal parameters defined by this executable fragment.
   List<FormalParameterFragmentImpl> get parameters {
@@ -2940,7 +2939,7 @@ class FieldFragmentImpl extends PropertyInducingFragmentImpl
       super.nextFragment as FieldFragmentImpl?;
 
   @override
-  int get offset => isSynthetic ? enclosingFragment.offset : _nameOffset;
+  int get offset => isSynthetic ? enclosingFragment.offset : nameOffset;
 
   @override
   FieldFragmentImpl? get previousFragment =>
@@ -3580,10 +3579,10 @@ mixin FragmentedTypeParameterizedElementMixin<
   }
 }
 
-abstract class FragmentImpl implements FragmentOrMember {
+abstract class FragmentImpl implements Fragment {
   static int _NEXT_ID = 0;
 
-  @override
+  /// The unique integer identifier of this fragment.
   final int id = _NEXT_ID++;
 
   /// The element that either physically or logically encloses this element.
@@ -3597,14 +3596,16 @@ abstract class FragmentImpl implements FragmentOrMember {
   FragmentImpl? enclosingElement3;
 
   /// The offset of the name of this element in the file that contains the
-  /// declaration of this element.
-  int _nameOffset = 0;
+  /// declaration of this element, or `-1` if this element is synthetic, does
+  /// not have a name, or otherwise does not have an offset.
+  int nameOffset = 0;
 
   /// The modifiers associated with this element.
   EnumSet<Modifier> _modifiers = EnumSet.empty();
 
-  /// The documentation comment for this element.
-  String? _docComment;
+  /// The content of the documentation comment (including delimiters) for this
+  /// element, or `null` if this element does not or cannot have documentation.
+  String? documentationComment;
 
   /// The offset of the beginning of the element's code in the file that
   /// contains the element, or `null` if the element is synthetic.
@@ -3615,7 +3616,7 @@ abstract class FragmentImpl implements FragmentOrMember {
 
   /// Initialize a newly created element to have the given [name] at the given
   /// [_nameOffset].
-  FragmentImpl({required int nameOffset}) : _nameOffset = nameOffset;
+  FragmentImpl({required this.nameOffset});
 
   /// The length of the element's code, or `null` if the element is synthetic.
   int? get codeLength => _codeLength;
@@ -3624,25 +3625,28 @@ abstract class FragmentImpl implements FragmentOrMember {
   /// contains the element, or `null` if the element is synthetic.
   int? get codeOffset => _codeOffset;
 
-  @override
+  /// The analysis context in which this element is defined.
   AnalysisContext get context {
     return library!.context;
   }
 
-  @override
+  /// The declaration of this element.
+  ///
+  /// If the element is a view on an element, e.g. a method from an interface
+  /// type, with substituted type parameters, return the corresponding element
+  /// from the class, without any substitutions. If this element is already a
+  /// declaration (or a synthetic element, e.g. a synthetic property accessor),
+  /// return itself.
   FragmentImpl get declaration => this;
 
-  @override
+  /// The display name of this element, possibly the empty string if the
+  /// element does not have a name.
+  ///
+  /// In most cases the name and the display name are the same. Differences
+  /// though are cases such as setters where the name of some setter `set f(x)`
+  /// is `f=`, instead of `f`.
   String get displayName => name2 ?? '';
 
-  @override
-  String? get documentationComment => _docComment;
-
-  /// The documentation comment source for this element.
-  set documentationComment(String? doc) {
-    _docComment = doc;
-  }
-
   /// Return the enclosing unit element (which might be the same as `this`), or
   /// `null` if this element is not contained in any compilation unit.
   LibraryFragmentImpl get enclosingUnit {
@@ -3653,7 +3657,10 @@ abstract class FragmentImpl implements FragmentOrMember {
     return library!.featureSet.isEnabled(Feature.nonfunction_type_aliases);
   }
 
-  @override
+  /// Whether the element is private.
+  ///
+  /// Private elements are visible only within the library in which they are
+  /// declared.
   bool get isPrivate {
     var name = name2;
     if (name == null) {
@@ -3662,10 +3669,17 @@ abstract class FragmentImpl implements FragmentOrMember {
     return Identifier.isPrivateName(name);
   }
 
-  @override
+  /// Whether the element is public.
+  ///
+  /// Public elements are visible within any library that imports the library
+  /// in which they are declared.
   bool get isPublic => !isPrivate;
 
-  @override
+  /// Whether the element is synthetic.
+  ///
+  /// A synthetic element is an element that is not represented in the source
+  /// code explicitly, but is implied by the source code, such as the default
+  /// constructor for a class that does not explicitly define any constructors.
   bool get isSynthetic {
     return hasModifier(Modifier.SYNTHETIC);
   }
@@ -3675,38 +3689,50 @@ abstract class FragmentImpl implements FragmentOrMember {
     setModifier(Modifier.SYNTHETIC, isSynthetic);
   }
 
+  /// The kind of element that this is.
+  // TODO(scheglov): remove it
+  ElementKind get kind;
+
   LibraryElementImpl? get library;
 
-  @override
+  /// If this target is associated with a library, return the source of the
+  /// library's defining compilation unit; otherwise return `null`.
   Source? get librarySource => library?.source;
 
   String? get lookupName {
     return name2;
   }
 
-  @override
+  /// The length of the name of this element in the file that contains the
+  /// declaration of this element, or `0` if this element does not have a name.
   int get nameLength => displayName.length;
 
-  @override
-  int get nameOffset => _nameOffset;
-
-  /// Sets the offset of the name of this element in the file that contains the
-  /// declaration of this element.
-  set nameOffset(int offset) {
-    _nameOffset = offset;
-  }
-
-  @override
+  /// The analysis session in which this element is defined.
   AnalysisSession? get session {
     return enclosingElement3?.session;
   }
 
-  @override
+  /// The version where this SDK API was added.
+  ///
+  /// A `@Since()` annotation can be applied to a library declaration,
+  /// any public declaration in a library, or in a class, or to an optional
+  /// parameter, etc.
+  ///
+  /// The returned version is "effective", so that if a library is annotated
+  /// then all elements of the library inherit it; or if a class is annotated
+  /// then all members and constructors of the class inherit it.
+  ///
+  /// If multiple `@Since()` annotations apply to the same element, the latest
+  /// version takes precedence.
+  ///
+  /// Returns `null` if the element is not declared in SDK, or does not have
+  /// a `@Since()` annotation applicable to it.
   Version? get sinceSdkVersion {
     return asElement2.ifTypeOrNull<HasSinceSdkVersion>()?.sinceSdkVersion;
   }
 
-  @override
+  /// Return the source associated with this target, or `null` if this target is
+  /// not associated with a source.
   Source? get source {
     return enclosingElement3?.source;
   }
@@ -3739,7 +3765,22 @@ abstract class FragmentImpl implements FragmentOrMember {
     }
   }
 
-  @override
+  /// Returns the presentation of this element as it should appear when
+  /// presented to users.
+  ///
+  /// If [withNullability] is `true`, then [NullabilitySuffix.question] and
+  /// [NullabilitySuffix.star] in types will be represented as `?` and `*`.
+  /// [NullabilitySuffix.none] does not have any explicit presentation.
+  ///
+  /// If [withNullability] is `false`, nullability suffixes will not be
+  /// included into the presentation.
+  ///
+  /// If [multiline] is `true`, the string may be wrapped over multiple lines
+  /// with newlines to improve formatting. For example function signatures may
+  /// be formatted as if they had trailing commas.
+  ///
+  /// Clients should not depend on the content of the returned value as it will
+  /// be changed if doing so would improve the UX.
   String getDisplayString({
     @Deprecated('Only non-nullable by default mode is supported')
     bool withNullability = true,
@@ -3783,118 +3824,6 @@ abstract class FragmentImpl implements FragmentOrMember {
   }
 }
 
-/// A shared internal interface of `Element` and [Member].
-/// Used during migration to avoid referencing `Element`.
-abstract class FragmentOrMember implements Fragment {
-  /// The analysis context in which this element is defined.
-  AnalysisContext get context;
-
-  /// The declaration of this element.
-  ///
-  /// If the element is a view on an element, e.g. a method from an interface
-  /// type, with substituted type parameters, return the corresponding element
-  /// from the class, without any substitutions. If this element is already a
-  /// declaration (or a synthetic element, e.g. a synthetic property accessor),
-  /// return itself.
-  FragmentOrMember? get declaration;
-
-  /// The display name of this element, possibly the empty string if the
-  /// element does not have a name.
-  ///
-  /// In most cases the name and the display name are the same. Differences
-  /// though are cases such as setters where the name of some setter `set f(x)`
-  /// is `f=`, instead of `f`.
-  String get displayName;
-
-  /// The content of the documentation comment (including delimiters) for this
-  /// element, or `null` if this element does not or cannot have documentation.
-  String? get documentationComment;
-
-  /// The unique integer identifier of this element.
-  int get id;
-
-  /// Whether the element is private.
-  ///
-  /// Private elements are visible only within the library in which they are
-  /// declared.
-  bool get isPrivate;
-
-  /// Whether the element is public.
-  ///
-  /// Public elements are visible within any library that imports the library
-  /// in which they are declared.
-  bool get isPublic;
-
-  /// Whether the element is synthetic.
-  ///
-  /// A synthetic element is an element that is not represented in the source
-  /// code explicitly, but is implied by the source code, such as the default
-  /// constructor for a class that does not explicitly define any constructors.
-  bool get isSynthetic;
-
-  /// The kind of element that this is.
-  ElementKind get kind;
-
-  /// If this target is associated with a library, return the source of the
-  /// library's defining compilation unit; otherwise return `null`.
-  Source? get librarySource;
-
-  /// The length of the name of this element in the file that contains the
-  /// declaration of this element, or `0` if this element does not have a name.
-  int get nameLength;
-
-  /// The offset of the name of this element in the file that contains the
-  /// declaration of this element, or `-1` if this element is synthetic, does
-  /// not have a name, or otherwise does not have an offset.
-  int get nameOffset;
-
-  /// The analysis session in which this element is defined.
-  AnalysisSession? get session;
-
-  /// The version where this SDK API was added.
-  ///
-  /// A `@Since()` annotation can be applied to a library declaration,
-  /// any public declaration in a library, or in a class, or to an optional
-  /// parameter, etc.
-  ///
-  /// The returned version is "effective", so that if a library is annotated
-  /// then all elements of the library inherit it; or if a class is annotated
-  /// then all members and constructors of the class inherit it.
-  ///
-  /// If multiple `@Since()` annotations apply to the same element, the latest
-  /// version takes precedence.
-  ///
-  /// Returns `null` if the element is not declared in SDK, or does not have
-  /// a `@Since()` annotation applicable to it.
-  Version? get sinceSdkVersion;
-
-  /// Return the source associated with this target, or `null` if this target is
-  /// not associated with a source.
-  Source? get source;
-
-  /// Returns the presentation of this element as it should appear when
-  /// presented to users.
-  ///
-  /// If [withNullability] is `true`, then [NullabilitySuffix.question] and
-  /// [NullabilitySuffix.star] in types will be represented as `?` and `*`.
-  /// [NullabilitySuffix.none] does not have any explicit presentation.
-  ///
-  /// If [withNullability] is `false`, nullability suffixes will not be
-  /// included into the presentation.
-  ///
-  /// If [multiline] is `true`, the string may be wrapped over multiple lines
-  /// with newlines to improve formatting. For example function signatures may
-  /// be formatted as if they had trailing commas.
-  ///
-  /// Clients should not depend on the content of the returned value as it will
-  /// be changed if doing so would improve the UX.
-  String getDisplayString({
-    @Deprecated('Only non-nullable by default mode is supported')
-    bool withNullability = true,
-    bool multiline = false,
-  });
-}
-
 sealed class FunctionFragmentImpl extends ExecutableFragmentImpl
     implements FunctionTypedFragmentImpl {
   @override
@@ -4109,7 +4038,7 @@ class GenericFunctionTypeFragmentImpl extends _ExistingFragmentImpl
   GenericFunctionTypeFragmentImpl? get nextFragment => null;
 
   @override
-  int get offset => _nameOffset;
+  int get offset => nameOffset;
 
   @override
   List<FormalParameterFragmentImpl> get parameters {
@@ -4855,7 +4784,7 @@ abstract class InstanceFragmentImpl extends _ExistingFragmentImpl
   List<MethodFragment> get methods2 => methods.cast<MethodFragment>();
 
   @override
-  int get offset => _nameOffset;
+  int get offset => nameOffset;
 
   @override
   List<SetterFragmentImpl> get setters {
@@ -5633,7 +5562,7 @@ class LabelFragmentImpl extends FragmentImpl implements LabelFragment {
   LabelFragmentImpl? get nextFragment => null;
 
   @override
-  int get offset => _nameOffset;
+  int get offset => nameOffset;
 
   @override
   LabelFragmentImpl? get previousFragment => null;
@@ -8582,7 +8511,7 @@ sealed class PropertyAccessorFragmentImpl extends ExecutableFragmentImpl
       }
       return variable.firstFragment.offset;
     }
-    return _nameOffset;
+    return nameOffset;
   }
 }