Introduce code to generate UnlinkedPublicNamespace directly from an AST.

pkg/analyzer/lib/src/summary/public_namespace_computer.dart

+// 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.
+
+library analyzer.src.summary.public_namespace_visitor;
+
+import 'package:analyzer/analyzer.dart';
+import 'package:analyzer/src/summary/base.dart';
+import 'package:analyzer/src/summary/format.dart';
+
+/**
+ * Compute the public namespace portion of the summary for the given [unit],
+ * which is presumed to be an unresolved AST.
+ */
+UnlinkedPublicNamespaceBuilder computePublicNamespace(
+    BuilderContext ctx, CompilationUnit unit) {
+  _PublicNamespaceVisitor visitor = new _PublicNamespaceVisitor(ctx);
+  unit.accept(visitor);
+  return encodeUnlinkedPublicNamespace(ctx,
+      names: visitor.names, exports: visitor.exports, parts: visitor.parts);
+}
+
+class _CombinatorEncoder extends SimpleAstVisitor<UnlinkedCombinatorBuilder> {
+  final BuilderContext ctx;
+
+  _CombinatorEncoder(this.ctx);
+
+  List<UnlinkedCombinatorNameBuilder> encodeNames(
+          NodeList<SimpleIdentifier> names) =>
+      names
+          .map((SimpleIdentifier id) =>
+              encodeUnlinkedCombinatorName(ctx, name: id.name))
+          .toList();
+
+  @override
+  UnlinkedCombinatorBuilder visitHideCombinator(HideCombinator node) {
+    return encodeUnlinkedCombinator(ctx, hides: encodeNames(node.hiddenNames));
+  }
+
+  @override
+  UnlinkedCombinatorBuilder visitShowCombinator(ShowCombinator node) {
+    return encodeUnlinkedCombinator(ctx, shows: encodeNames(node.shownNames));
+  }
+}
+
+class _PublicNamespaceVisitor extends RecursiveAstVisitor {
+  final BuilderContext ctx;
+  final List<UnlinkedPublicNameBuilder> names = <UnlinkedPublicNameBuilder>[];
+  final List<UnlinkedExportBuilder> exports = <UnlinkedExportBuilder>[];
+  final List<UnlinkedPartBuilder> parts = <UnlinkedPartBuilder>[];
+
+  _PublicNamespaceVisitor(this.ctx);
+
+  void addNameIfPublic(String name, PrelinkedReferenceKind kind) {
+    if (isPublic(name)) {
+      names.add(encodeUnlinkedPublicName(ctx, name: name, kind: kind));
+    }
+  }
+
+  bool isPublic(String name) => !name.startsWith('_');
+
+  @override
+  visitClassDeclaration(ClassDeclaration node) {
+    addNameIfPublic(node.name.name, PrelinkedReferenceKind.classOrEnum);
+  }
+
+  @override
+  visitClassTypeAlias(ClassTypeAlias node) {
+    addNameIfPublic(node.name.name, PrelinkedReferenceKind.classOrEnum);
+  }
+
+  @override
+  visitEnumDeclaration(EnumDeclaration node) {
+    addNameIfPublic(node.name.name, PrelinkedReferenceKind.classOrEnum);
+  }
+
+  @override
+  visitExportDirective(ExportDirective node) {
+    exports.add(encodeUnlinkedExport(ctx,
+        uri: node.uri.stringValue,
+        combinators: node.combinators
+            .map((Combinator c) => c.accept(new _CombinatorEncoder(ctx)))
+            .toList()));
+  }
+
+  @override
+  visitFunctionDeclaration(FunctionDeclaration node) {
+    String name = node.name.name;
+    if (node.isSetter) {
+      name += '=';
+    }
+    addNameIfPublic(name, PrelinkedReferenceKind.other);
+  }
+
+  @override
+  visitFunctionTypeAlias(FunctionTypeAlias node) {
+    addNameIfPublic(node.name.name, PrelinkedReferenceKind.typedef);
+  }
+
+  @override
+  visitPartDirective(PartDirective node) {
+    parts.add(encodeUnlinkedPart(ctx, uri: node.uri.stringValue));
+  }
+
+  @override
+  visitVariableDeclaration(VariableDeclaration node) {
+    String name = node.name.name;
+    addNameIfPublic(name, PrelinkedReferenceKind.other);
+    if (!node.isFinal && !node.isConst) {
+      addNameIfPublic('$name=', PrelinkedReferenceKind.other);
+    }
+  }
+}