Revert "Add typedef AST node boilerplate."

pkg/kernel/lib/ast.dart

Index: pkg/kernel/lib/ast.dart
diff --git a/pkg/kernel/lib/ast.dart b/pkg/kernel/lib/ast.dart
index daa5427e83ab2e3d8af16aec6b0c292b3b547747..d93b704191debdf92ea41a532e35422977e1b13e 100644
--- a/pkg/kernel/lib/ast.dart
+++ b/pkg/kernel/lib/ast.dart
@@ -228,13 +228,6 @@ class Reference {
     }
     return node as Procedure;
   }
-
-  Typedef get asTypedef {
-    if (node == null) {
-      throw '$this is not bound to an AST node. A typedef was expected';
-    }
-    return node as Typedef;
-  }
 }
 
 // ------------------------------------------------------------------------
@@ -265,7 +258,6 @@ class Library extends NamedNode implements Comparable<Library> {
 
   String name;
   final List<DeferredImport> deferredImports;
-  final List<Typedef> typedefs;
   final List<Class> classes;
   final List<Procedure> procedures;
   final List<Field> fields;
@@ -274,20 +266,16 @@ class Library extends NamedNode implements Comparable<Library> {
       {this.name,
       this.isExternal: false,
       List<DeferredImport> imports,
-      List<Typedef> typedefs,
       List<Class> classes,
       List<Procedure> procedures,
       List<Field> fields,
       this.fileUri,
       Reference reference})
       : this.deferredImports = imports ?? <DeferredImport>[],
-        this.typedefs = typedefs ?? <Typedef>[],
         this.classes = classes ?? <Class>[],
         this.procedures = procedures ?? <Procedure>[],
         this.fields = fields ?? <Field>[],
         super(reference) {
-    setParents(this.deferredImports, this);
-    setParents(this.typedefs, this);
     setParents(this.classes, this);
     setParents(this.procedures, this);
     setParents(this.fields, this);
@@ -316,16 +304,8 @@ class Library extends NamedNode implements Comparable<Library> {
     classes.add(class_);
   }
 
-  void addTypedef(Typedef typedef_) {
-    typedef_.parent = this;
-    typedefs.add(typedef_);
-  }
-
   void computeCanonicalNames() {
     assert(canonicalName != null);
-    for (var typedef_ in typedefs) {
-      canonicalName.getChildFromTypedef(typedef_).bindTo(typedef_.reference);
-    }
     for (var field in fields) {
       canonicalName.getChildFromMember(field).bindTo(field.reference);
     }
@@ -341,16 +321,12 @@ class Library extends NamedNode implements Comparable<Library> {
   accept(TreeVisitor v) => v.visitLibrary(this);
 
   visitChildren(Visitor v) {
-    visitList(deferredImports, v);
-    visitList(typedefs, v);
     visitList(classes, v);
     visitList(procedures, v);
     visitList(fields, v);
   }
 
   transformChildren(Transformer v) {
-    transformList(deferredImports, v, this);
-    transformList(typedefs, v, this);
     transformList(classes, v, this);
     transformList(procedures, v, this);
     transformList(fields, v, this);
@@ -390,51 +366,6 @@ class DeferredImport extends TreeNode {
   transformChildren(Transformer v) {}
 }
 
-/// Declaration of a type alias.
-class Typedef extends NamedNode {
-  /// The uri of the source file that contains the declaration of this typedef.
-  String fileUri;
-  List<Expression> annotations = const <Expression>[];
-  String name;
-  final List<TypeParameter> typeParameters;
-  DartType type;
-
-  Typedef(this.name, this.type,
-      {Reference reference, this.fileUri, List<TypeParameter> typeParameters})
-      : this.typeParameters = typeParameters ?? <TypeParameter>[],
-        super(reference) {
-    setParents(this.typeParameters, this);
-  }
-
-  Library get enclosingLibrary => parent;
-
-  accept(TreeVisitor v) {
-    return v.visitTypedef(this);
-  }
-
-  transformChildren(Transformer v) {
-    transformList(annotations, v, this);
-    transformList(typeParameters, v, this);
-    if (type != null) {
-      type = v.visitDartType(type);
-    }
-  }
-
-  visitChildren(Visitor v) {
-    visitList(annotations, v);
-    visitList(typeParameters, v);
-    type?.accept(v);
-  }
-
-  void addAnnotation(Expression node) {
-    if (annotations.isEmpty) {
-      annotations = <Expression>[];
-    }
-    annotations.add(node);
-    node.parent = this;
-  }
-}
-
 /// The degree to which the contents of a class have been loaded into memory.
 ///
 /// Each level imply the requirements of the previous ones.
@@ -3764,16 +3695,6 @@ abstract class DartType extends Node {
   accept(DartTypeVisitor v);
 
   bool operator ==(Object other);
-
-  /// If this is a typedef type, repeatedly unfolds its type definition until
-  /// the root term is not a typedef type, otherwise returns the type itself.
-  ///
-  /// Will never return a typedef type.
-  DartType get unalias => this;
-
-  /// If this is a typedef type, unfolds its type definition once, otherwise
-  /// returns the type itself.
-  DartType get unaliasOnce => this;
 }
 
 /// The type arising from invalid type annotations.
@@ -4003,60 +3924,6 @@ class FunctionType extends DartType {
   }
 }
 
-/// A use of a [Typedef] as a type.
-///
-/// The underlying type can be extracted using [unalias].
-class TypedefType extends DartType {
-  final Reference typedefReference;
-  final List<DartType> typeArguments;
-
-  TypedefType(Typedef typedefNode, [List<DartType> typeArguments])
-      : this.byReference(
-            typedefNode.reference, typeArguments ?? const <DartType>[]);
-
-  TypedefType.byReference(this.typedefReference, this.typeArguments);
-
-  Typedef get typedefNode => typedefReference.asTypedef;
-
-  accept(DartTypeVisitor v) => v.visitTypedefType(this);
-
-  visitChildren(Visitor v) {
-    visitList(typeArguments, v);
-    v.visitTypedefReference(typedefNode);
-  }
-
-  DartType get unaliasOnce {
-    return Substitution.fromTypedefType(this).substituteType(typedefNode.type);
-  }
-
-  DartType get unalias {
-    return unaliasOnce.unalias;
-  }
-
-  bool operator ==(Object other) {
-    if (identical(this, other)) return true;
-    if (other is TypedefType) {
-      if (typedefReference != other.typedefReference ||
-          typeArguments.length != other.typeArguments.length) {
-        return false;
-      }
-      for (int i = 0; i < typeArguments.length; ++i) {
-        if (typeArguments[i] != other.typeArguments[i]) return false;
-      }
-      return true;
-    }
-    return false;
-  }
-
-  int get hashCode {
-    int hash = 0x3fffffff & typedefNode.hashCode;
-    for (int i = 0; i < typeArguments.length; ++i) {
-      hash = 0x3fffffff & (hash * 31 + (hash ^ typeArguments[i].hashCode));
-    }
-    return hash;
-  }
-}
-
 /// A named parameter in [FunctionType].
 class NamedType extends Node implements Comparable<NamedType> {
   final String name;
@@ -4456,15 +4323,3 @@ CanonicalName getCanonicalNameOfLibrary(Library library) {
   }
   return library.canonicalName;
 }
-
-/// Returns the canonical name of [typedef_], or throws an exception if the
-/// typedef has not been assigned a canonical name yet.
-///
-/// Returns `null` if the typedef is `null`.
-CanonicalName getCanonicalNameOfTypedef(Typedef typedef_) {
-  if (typedef_ == null) return null;
-  if (typedef_.canonicalName == null) {
-    throw '$typedef_ has no canonical name';
-  }
-  return typedef_.canonicalName;
-}