Move scope.dart.

pkg/front_end/lib/src/fasta/builder/scope.dart

-// Copyright (c) 2016, 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.
-
-library fasta.scope;
-
-import 'builder.dart' show Builder, MixedAccessor;
-
-import '../errors.dart' show internalError;
-
-class Scope {
-  /// Names declared in this scope.
-  final Map<String, Builder> local;
-
-  /// The scope that this scope is nested within, or `null` if this is the top
-  /// level scope.
-  final Scope parent;
-
-  /// Indicates whether an attempt to declare new names in this scope should
-  /// succeed.
-  final bool isModifiable;
-
-  Map<String, Builder> labels;
-
-  Map<String, Builder> forwardDeclaredLabels;
-
-  Scope(this.local, this.parent, {this.isModifiable: true});
-
-  Scope createNestedScope({bool isModifiable: true}) {
-    return new Scope(<String, Builder>{}, this, isModifiable: isModifiable);
-  }
-
-  Builder lookup(String name, int charOffset, Uri fileUri) {
-    Builder builder = local[name];
-    if (builder != null) {
-      if (builder.next != null) {
-        return lookupAmbiguous(name, builder, false, charOffset, fileUri);
-      }
-      return builder.isSetter
-          ? new AccessErrorBuilder(name, builder, charOffset, fileUri)
-          : builder;
-    } else {
-      return parent?.lookup(name, charOffset, fileUri);
-    }
-  }
-
-  Builder lookupSetter(String name, int charOffset, Uri fileUri) {
-    Builder builder = local[name];
-    if (builder != null) {
-      if (builder.next != null) {
-        return lookupAmbiguous(name, builder, true, charOffset, fileUri);
-      }
-      if (builder.isField) {
-        if (builder.isFinal) {
-          return new AccessErrorBuilder(name, builder, charOffset, fileUri);
-        } else {
-          return builder;
-        }
-      } else if (builder.isSetter) {
-        return builder;
-      } else {
-        return new AccessErrorBuilder(name, builder, charOffset, fileUri);
-      }
-    } else {
-      return parent?.lookupSetter(name, charOffset, fileUri);
-    }
-  }
-
-  Builder lookupAmbiguous(
-      String name, Builder builder, bool setter, int charOffset, Uri fileUri) {
-    assert(builder.next != null);
-    if (builder is MixedAccessor) {
-      return setter ? builder.setter : builder.getter;
-    }
-    Builder setterBuilder;
-    Builder getterBuilder;
-    Builder current = builder;
-    while (current != null) {
-      if (current.isGetter && getterBuilder == null) {
-        getterBuilder = current;
-      } else if (current.isSetter && setterBuilder == null) {
-        setterBuilder = current;
-      } else {
-        return new AmbiguousBuilder(name, builder, charOffset, fileUri);
-      }
-      current = current.next;
-    }
-    assert(getterBuilder != null);
-    assert(setterBuilder != null);
-    return setter ? setterBuilder : getterBuilder;
-  }
-
-  bool hasLocalLabel(String name) => labels != null && labels.containsKey(name);
-
-  void declareLabel(String name, Builder target) {
-    if (isModifiable) {
-      labels ??= <String, Builder>{};
-      labels[name] = target;
-    } else {
-      internalError("Can't extend an unmodifiable scope.");
-    }
-  }
-
-  void forwardDeclareLabel(String name, Builder target) {
-    declareLabel(name, target);
-    forwardDeclaredLabels ??= <String, Builder>{};
-    forwardDeclaredLabels[name] = target;
-  }
-
-  void claimLabel(String name) {
-    if (forwardDeclaredLabels == null) return;
-    forwardDeclaredLabels.remove(name);
-    if (forwardDeclaredLabels.length == 0) {
-      forwardDeclaredLabels = null;
-    }
-  }
-
-  Map<String, Builder> get unclaimedForwardDeclarations {
-    return forwardDeclaredLabels;
-  }
-
-  Builder lookupLabel(String name) {
-    return (labels == null ? null : labels[name]) ?? parent?.lookupLabel(name);
-  }
-
-  // TODO(ahe): Rename to extend or something.
-  void operator []=(String name, Builder member) {
-    if (isModifiable) {
-      local[name] = member;
-    } else {
-      internalError("Can't extend an unmodifiable scope.");
-    }
-  }
-}
-
-abstract class ProblemBuilder extends Builder {
-  final String name;
-
-  final Builder builder;
-
-  ProblemBuilder(this.name, this.builder, int charOffset, Uri fileUri)
-      : super(null, charOffset, fileUri);
-
-  get target => null;
-
-  bool get hasProblem => true;
-
-  String get message;
-
-  @override
-  String get fullNameForErrors => name;
-}
-
-/// Represents a [builder] that's being accessed incorrectly. For example, an
-/// attempt to write to a final field, or to read from a setter.
-class AccessErrorBuilder extends ProblemBuilder {
-  AccessErrorBuilder(String name, Builder builder, int charOffset, Uri fileUri)
-      : super(name, builder, charOffset, fileUri);
-
-  Builder get parent => builder;
-
-  bool get isFinal => builder.isFinal;
-
-  bool get isField => builder.isField;
-
-  bool get isRegularMethod => builder.isRegularMethod;
-
-  bool get isGetter => !builder.isGetter;
-
-  bool get isSetter => !builder.isSetter;
-
-  bool get isInstanceMember => builder.isInstanceMember;
-
-  bool get isStatic => builder.isStatic;
-
-  bool get isTopLevel => builder.isTopLevel;
-
-  bool get isTypeDeclaration => builder.isTypeDeclaration;
-
-  bool get isLocal => builder.isLocal;
-
-  String get message => "Access error: '$name'.";
-}
-
-class AmbiguousBuilder extends ProblemBuilder {
-  AmbiguousBuilder(String name, Builder builder, int charOffset, Uri fileUri)
-      : super(name, builder, charOffset, fileUri);
-
-  String get message => "Duplicated named: '$name'.";
-}