Refactor dartdoc into a class. Use method overriding to extend.

utils/dartdoc/dartdoc.dart

 // Copyright (c) 2011, 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.
 
 /**
  * To use it, from this directory, run:
  *
  *     $ dartdoc <path to .dart file>
  *
  * This will create a "docs" directory with the docs for your libraries. To
  * create these beautiful docs, dartdoc parses your library and every library
  * it imports (recursively). From each library, it parses all classes and
  * members, finds the associated doc comments and builds crosslinked docs from
  * them.
  */
 #library('dartdoc');
 
 #import('../../frog/lang.dart');
 #import('../../frog/file_system.dart');
 #import('../../frog/file_system_node.dart');
 #import('../markdown/lib.dart', prefix: 'md');
 
 #source('classify.dart');
+#source('comment_map.dart');
 #source('files.dart');
 #source('utils.dart');
 
 /** Path to corePath library. */
 final corePath = 'lib';
 
 /** Path to generate html files into. */
 final outdir = 'docs';
 
-/** Set to `false` to not include the source code in the generated docs. */
-bool includeSource = true;
-
 FileSystem files;
 
-/** Special comment position used to store the library-level doc comment. */
-final _libraryDoc = -1;
-
-/** The library that we're currently generating docs for. */
-Library _currentLibrary;
-
-/** The type that we're currently generating docs for. */
-Type _currentType;
-
-/** The member that we're currently generating docs for. */
-Member _currentMember;
-
-/**
- * The cached lookup-table to associate doc comments with spans. The outer map
- * is from filenames to doc comments in that file. The inner map maps from the
- * token positions to doc comments. Each position is the starting offset of the
- * next non-comment token *following* the doc comment. For example, the position
- * for this comment would be the position of the "Map" token below.
- */
-Map<String, Map<int, String>> _comments;
-
-/** A callback that returns additional Markdown documentation for a type. */
-typedef String TypeDocumenter(Type type);
-
-/** A list of callbacks registered for documenting types. */
-List<TypeDocumenter> _typeDocumenters;
-
-/** A callback that returns additional Markdown documentation for a method. */
-typedef String MethodDocumenter(MethodMember method);
-
-/** A list of callbacks registered for documenting methods. */
-List<MethodDocumenter> _methodDocumenters;
-
-/** A callback that returns additional Markdown documentation for a field. */
-typedef String FieldDocumenter(FieldMember field);
-
-/** A list of callbacks registered for documenting fields. */
-List<FieldDocumenter> _fieldDocumenters;
-
-int _totalLibraries = 0;
-int _totalTypes = 0;
-int _totalMembers = 0;
-
 /**
  * Run this from the `utils/dartdoc` directory.
  */
 void main() {
   // The entrypoint of the library to generate docs for.
-  final entrypoint = process.argv[2];
+  final entrypoint = process.argv[process.argv.length - 1];
 
   // Parse the dartdoc options.
-  for (int i = 3; i < process.argv.length; i++) {
+  bool includeSource = true;
+
+  for (int i = 2; i < process.argv.length - 1; i++) {
     final arg = process.argv[i];
     switch (arg) {
       case '--no-code':
         includeSource = false;
         break;
 
       default:
         print('Unknown option: $arg');
     }
   }
 
   files = new NodeFileSystem();
   parseOptions('../../frog', [] /* args */, files);
   initializeWorld(files);
 
+  var dartdoc;
   final elapsed = time(() {
-    initializeDartDoc();
-    document(entrypoint);
+    dartdoc = new Dartdoc();
+    dartdoc.includeSource = includeSource;
+    dartdoc.document(entrypoint);
   });
 
-  printStats(elapsed);
+  print('Documented ${dartdoc._totalLibraries} libraries, ' +
+      '${dartdoc._totalTypes} types, and ' +
+      '${dartdoc._totalMembers} members in ${elapsed}msec.');
 }
 
-void initializeDartDoc() {
-  _comments = <Map<int, String>>{};
-  _typeDocumenters = <TypeDocumenter>[];
-  _methodDocumenters = <MethodDocumenter>[];
-  _fieldDocumenters = <FieldDocumenter>[];
-
-  // Patch in support for [:...:]-style code to the markdown parser.
-  // TODO(rnystrom): Markdown already has syntax for this. Phase this out?
-  md.InlineParser.syntaxes.insertRange(0, 1,
-      new md.CodeSyntax(@'\[\:((?:.|\n)*?)\:\]'));
-
-  md.setImplicitLinkResolver(resolveNameReference);
-}
-
-document(String entrypoint) {
-  try {
-    var oldDietParse = options.dietParse;
-    options.dietParse = true;
-
-    // Handle the built-in entrypoints.
-    switch (entrypoint) {
-      case 'corelib':
-        world.getOrAddLibrary('dart:core');
-        world.getOrAddLibrary('dart:coreimpl');
-        world.getOrAddLibrary('dart:json');
-        world.process();
-        break;
-
-      case 'dom':
-        world.getOrAddLibrary('dart:core');
-        world.getOrAddLibrary('dart:coreimpl');
-        world.getOrAddLibrary('dart:json');
-        world.getOrAddLibrary('dart:dom');
-        world.process();
-        break;
-
-      case 'html':
-        world.getOrAddLibrary('dart:core');
-        world.getOrAddLibrary('dart:coreimpl');
-        world.getOrAddLibrary('dart:json');
-        world.getOrAddLibrary('dart:dom');
-        world.getOrAddLibrary('dart:html');
-        world.process();
-        break;
-
-      default:
-        // Normal entrypoint script.
-        world.processDartScript(entrypoint);
-    }
-
-    world.resolveAll();
-
-    // Generate the docs.
-    docIndex();
-    for (final library in world.libraries.getValues()) {
-      docLibrary(library);
-    }
-  } finally {
-    options.dietParse = oldDietParse;
-  }
-}
-
-printStats(num elapsed) {
-  print('Documented $_totalLibraries libraries, $_totalTypes types, and ' +
-      '$_totalMembers members in ${elapsed}msec.');
-}
-
-writeHeader(String title) {
-  writeln(
-      '''
-      <!DOCTYPE html>
-      <html>
-      <head>
-      <meta charset="utf-8">
-      <title>$title</title>
-      <link rel="stylesheet" type="text/css"
-          href="${relativePath('styles.css')}" />
-      <link href="http://fonts.googleapis.com/css?family=Open+Sans:400,600,700,800" rel="stylesheet" type="text/css">
-      <script src="${relativePath('interact.js')}"></script>
-      </head>
-      <body>
-      <div class="page">
-      ''');
-  docNavigation();
-  writeln('<div class="content">');
-}
-
-writeFooter() {
-  writeln(
-      '''
-      </div>
-      <div class="footer"</div>
-      </body></html>
-      ''');
-}
-
-docIndex() {
-  startFile('index.html');
-
-  writeHeader('Dart Documentation');
-
-  writeln('<h1>Dart Documentation</h1>');
-  writeln('<h3>Libraries</h3>');
-
-  for (final library in orderByName(world.libraries)) {
+class Dartdoc {
+  /** Set to `false` to not include the source code in the generated docs. */
+  bool includeSource = true;
+
+  CommentMap _comments;
+
+  /** The library that we're currently generating docs for. */
+  Library _currentLibrary;
+
+  /** The type that we're currently generating docs for. */
+  Type _currentType;
+
+  /** The member that we're currently generating docs for. */
+  Member _currentMember;
+
+  int _totalLibraries = 0;
+  int _totalTypes = 0;
+  int _totalMembers = 0;
+
+  Dartdoc()
+    : _comments = new CommentMap() {
+    // Patch in support for [:...:]-style code to the markdown parser.
+    // TODO(rnystrom): Markdown already has syntax for this. Phase this out?
+    md.InlineParser.syntaxes.insertRange(0, 1,
+        new md.CodeSyntax(@'\[\:((?:.|\n)*?)\:\]'));
+
+    md.setImplicitLinkResolver(resolveNameReference);
+  }
+
+  document(String entrypoint) {
+    try {
+      var oldDietParse = options.dietParse;
+      options.dietParse = true;
+
+      // Handle the built-in entrypoints.
+      switch (entrypoint) {
+        case 'corelib':
+          world.getOrAddLibrary('dart:core');
+          world.getOrAddLibrary('dart:coreimpl');
+          world.getOrAddLibrary('dart:json');
+          world.process();
+          break;
+
+        case 'dom':
+          world.getOrAddLibrary('dart:core');
+          world.getOrAddLibrary('dart:coreimpl');
+          world.getOrAddLibrary('dart:json');
+          world.getOrAddLibrary('dart:dom');
+          world.process();
+          break;
+
+        case 'html':
+          world.getOrAddLibrary('dart:core');
+          world.getOrAddLibrary('dart:coreimpl');
+          world.getOrAddLibrary('dart:json');
+          world.getOrAddLibrary('dart:dom');
+          world.getOrAddLibrary('dart:html');
+          world.process();
+          break;
+
+        default:
+          // Normal entrypoint script.
+          world.processDartScript(entrypoint);
+      }
+
+      world.resolveAll();
+
+      // Generate the docs.
+      docIndex();
+      for (final library in world.libraries.getValues()) {
+        docLibrary(library);
+      }
+    } finally {
+      options.dietParse = oldDietParse;
+    }
+  }
+
+  writeHeader(String title) {
     writeln(
         '''
-        <h4>${a(libraryUrl(library), library.name)}</h4>
+        <!DOCTYPE html>
+        <html>
+        <head>
+        <meta charset="utf-8">
+        <title>$title</title>
+        <link rel="stylesheet" type="text/css"
+            href="${relativePath('styles.css')}" />
+        <link href="http://fonts.googleapis.com/css?family=Open+Sans:400,600,700,800" rel="stylesheet" type="text/css">
+        <script src="${relativePath('interact.js')}"></script>
+        </head>
+        <body>
+        <div class="page">
         ''');
-  }
-
-  writeFooter();
-  endFile();
-}
-
-docNavigation() {
-  writeln(
-      '''
-      <div class="nav">
-      <h1>${a("index.html", "Dart Documentation")}</h1>
-      ''');
-
-  for (final library in orderByName(world.libraries)) {
-    write('<h2><div class="icon-library"></div>');
-
-    if ((_currentLibrary == library) && (_currentType == null)) {
-      write('<strong>${library.name}</strong>');
-    } else {
-      write('${a(libraryUrl(library), library.name)}');
-    }
-    write('</h2>');
-
-    // Only expand classes in navigation for current library.
-    if (_currentLibrary == library) docLibraryNavigation(library);
-  }
-
-  writeln('</div>');
-}
-
-/** Writes the navigation for the types contained by the given library. */
-docLibraryNavigation(Library library) {
-  // Show the exception types separately.
-  final types = <Type>[];
-  final exceptions = <Type>[];
-
-  for (final type in orderByName(library.types)) {
-    if (type.isTop) continue;
-    if (type.name.startsWith('_')) continue;
-
-    if (type.name.endsWith('Exception')) {
-      exceptions.add(type);
-    } else {
-      types.add(type);
-    }
-  }
-
-  if ((types.length == 0) && (exceptions.length == 0)) return;
-
-  writeType(String icon, Type type) {
-    write('<li>');
-    if (_currentType == type) {
-      write(
-          '<div class="icon-$icon"></div><strong>${typeName(type)}</strong>');
-    } else {
-      write(a(typeUrl(type),
-          '<div class="icon-$icon"></div>${typeName(type)}'));
-    }
-    writeln('</li>');
-  }
-
-  writeln('<ul>');
-  types.forEach((type) => writeType(type.isClass ? 'class' : 'interface',
-      type));
-  exceptions.forEach((type) => writeType('exception', type));
-  writeln('</ul>');
-}
-
-String _runDocumenters(var item, List<Function> documenters) =>
-  Strings.join(map(documenters, (doc) => doc(item)), '\n\n');
-
-docLibrary(Library library) {
-  _totalLibraries++;
-  _currentLibrary = library;
-  _currentType = null;
-
-  startFile(libraryUrl(library));
-  writeHeader(library.name);
-  writeln('<h1>Library <strong>${library.name}</strong></h1>');
-
-  // Look for a comment for the entire library.
-  final comment = findCommentInFile(library.baseSource, _libraryDoc);
-  if (comment != null) {
-    final html = md.markdownToHtml(comment);
-    writeln('<div class="doc">$html</div>');
-  }
-
-  // Document the top-level members.
-  docMembers(library.topType);
-
-  // Document the types.
-  final classes = <Type>[];
-  final interfaces = <Type>[];
-  final exceptions = <Type>[];
-
-  for (final type in orderByName(library.types)) {
-    if (type.isTop) continue;
-    if (type.name.startsWith('_')) continue;
-
-    if (type.name.endsWith('Exception')) {
-      exceptions.add(type);
-    } else if (type.isClass) {
-      classes.add(type);
-    } else {
-      interfaces.add(type);
-    }
-  }
-
-  docTypes(classes, 'Classes');
-  docTypes(interfaces, 'Interfaces');
-  docTypes(exceptions, 'Exceptions');
-
-  writeFooter();
-  endFile();
-
-  for (final type in library.types.getValues()) {
-    if (!type.isTop) docType(type);
-  }
-}
-
-docTypes(List<Type> types, String header) {
-  if (types.length == 0) return;
-
-  writeln('<h3>$header</h3>');
-
-  for (final type in types) {
+    docNavigation();
+    writeln('<div class="content">');
+  }
+
+  writeFooter() {
     writeln(
         '''
-        <div class="type">
-        <h4>
-          ${a(typeUrl(type), "<strong>${typeName(type)}</strong>")}
+        </div>
+        <div class="footer"</div>
+        </body></html>
+        ''');
+  }
+
+  docIndex() {
+    startFile('index.html');
+
+    writeHeader('Dart Documentation');
+
+    writeln('<h1>Dart Documentation</h1>');
+    writeln('<h3>Libraries</h3>');
+
+    for (final library in orderByName(world.libraries)) {
+      writeln(
+          '''
+          <h4>${a(libraryUrl(library), library.name)}</h4>
+          ''');
+    }
+
+    writeFooter();
+    endFile();
+  }
+
+  docNavigation() {
+    writeln(
+        '''
+        <div class="nav">
+        <h1>${a("index.html", "Dart Documentation")}</h1>
+        ''');
+
+    for (final library in orderByName(world.libraries)) {
+      write('<h2><div class="icon-library"></div>');
+
+      if ((_currentLibrary == library) && (_currentType == null)) {
+        write('<strong>${library.name}</strong>');
+      } else {
+        write('${a(libraryUrl(library), library.name)}');
+      }
+      write('</h2>');
+
+      // Only expand classes in navigation for current library.
+      if (_currentLibrary == library) docLibraryNavigation(library);
+    }
+
+    writeln('</div>');
+  }
+
+  /** Writes the navigation for the types contained by the given library. */
+  docLibraryNavigation(Library library) {
+    // Show the exception types separately.
+    final types = <Type>[];
+    final exceptions = <Type>[];
+
+    for (final type in orderByName(library.types)) {
+      if (type.isTop) continue;
+      if (type.name.startsWith('_')) continue;
+
+      if (type.name.endsWith('Exception')) {
+        exceptions.add(type);
+      } else {
+        types.add(type);
+      }
+    }
+
+    if ((types.length == 0) && (exceptions.length == 0)) return;
+
+    writeType(String icon, Type type) {
+      write('<li>');
+      if (_currentType == type) {
+        write(
+            '<div class="icon-$icon"></div><strong>${typeName(type)}</strong>');
+      } else {
+        write(a(typeUrl(type),
+            '<div class="icon-$icon"></div>${typeName(type)}'));
+      }
+      writeln('</li>');
+    }
+
+    writeln('<ul>');
+    types.forEach((type) => writeType(type.isClass ? 'class' : 'interface',
+        type));
+    exceptions.forEach((type) => writeType('exception', type));
+    writeln('</ul>');
+  }
+
+  docLibrary(Library library) {
+    _totalLibraries++;
+    _currentLibrary = library;
+    _currentType = null;
+
+    startFile(libraryUrl(library));
+    writeHeader(library.name);
+    writeln('<h1>Library <strong>${library.name}</strong></h1>');
+
+    // Look for a comment for the entire library.
+    final comment = _comments.findLibrary(library.baseSource);
+    if (comment != null) {
+      final html = md.markdownToHtml(comment);
+      writeln('<div class="doc">$html</div>');
+    }
+
+    // Document the top-level members.
+    docMembers(library.topType);
+
+    // Document the types.
+    final classes = <Type>[];
+    final interfaces = <Type>[];
+    final exceptions = <Type>[];
+
+    for (final type in orderByName(library.types)) {
+      if (type.isTop) continue;
+      if (type.name.startsWith('_')) continue;
+
+      if (type.name.endsWith('Exception')) {
+        exceptions.add(type);
+      } else if (type.isClass) {
+        classes.add(type);
+      } else {
+        interfaces.add(type);
+      }
+    }
+
+    docTypes(classes, 'Classes');
+    docTypes(interfaces, 'Interfaces');
+    docTypes(exceptions, 'Exceptions');
+
+    writeFooter();
+    endFile();
+
+    for (final type in library.types.getValues()) {
+      if (!type.isTop) docType(type);
+    }
+  }
+
+  docTypes(List<Type> types, String header) {
+    if (types.length == 0) return;
+
+    writeln('<h3>$header</h3>');
+
+    for (final type in types) {
+      writeln(
+          '''
+          <div class="type">
+          <h4>
+            ${a(typeUrl(type), "<strong>${typeName(type)}</strong>")}
+          </h4>
+          </div>
+          ''');
+    }
+  }
+
+  docType(Type type) {
+    _totalTypes++;
+    _currentType = type;
+
+    startFile(typeUrl(type));
+
+    final typeTitle =
+      '${type.isClass ? "Class" : "Interface"} ${typeName(type)}';
+    writeHeader('Library ${type.library.name} / $typeTitle');
+    writeln(
+        '''
+        <h1>${a(libraryUrl(type.library),
+              "Library <strong>${type.library.name}</strong>")}</h1>
+        <h2>${type.isClass ? "Class" : "Interface"}
+            <strong>${typeName(type, showBounds: true)}</strong></h2>
+        ''');
+
+    docInheritance(type);
+
+    docCode(type.span, getTypeComment(type));
+    docConstructors(type);
+    docMembers(type);
+
+    writeFooter();
+    endFile();
+  }
+
+  /** Document the superclass, superinterfaces and default class of [Type]. */
+  docInheritance(Type type) {
+    final isSubclass = (type.parent != null) && !type.parent.isObject;
+
+    Type defaultType;
+    if (type.definition is TypeDefinition) {
+      TypeDefinition definition = type.definition;
+      if (definition.defaultType != null) {
+        defaultType = definition.defaultType.type;
+      }
+    }
+
+    if (isSubclass ||
+        (type.interfaces != null && type.interfaces.length > 0) ||
+        (defaultType != null)) {
+      writeln('<p>');
+
+      if (isSubclass) {
+        write('Extends ${typeReference(type.parent)}. ');
+      }
+
+      if (type.interfaces != null && type.interfaces.length > 0) {
+        var interfaceStr = joinWithCommas(map(type.interfaces, typeReference));
+        write('Implements ${interfaceStr}. ');
+      }
+
+      if (defaultType != null) {
+        write('Has default class ${typeReference(defaultType)}.');
+      }
+    }
+  }
+
+  /** Document the constructors for [Type], if any. */
+  docConstructors(Type type) {
+    final names = type.constructors.getKeys().filter(
+      (name) => !name.startsWith('_'));
+
+    if (names.length > 0) {
+      writeln('<h3>Constructors</h3>');
+      names.sort((x, y) => x.toUpperCase().compareTo(y.toUpperCase()));
+
+      for (final name in names) {
+        docMethod(type, type.constructors[name], constructorName: name);
+      }
+    }
+  }
+
+  void docMembers(Type type) {
+    // Collect the different kinds of members.
+    final methods = [];
+    final fields = [];
+
+    for (final member in orderByName(type.members)) {
+      if (member.name.startsWith('_')) continue;
+
+      if (member.isProperty) {
+        if (member.canGet) methods.add(member.getter);
+        if (member.canSet) methods.add(member.setter);
+      } else if (member.isMethod) {
+        methods.add(member);
+      } else if (member.isField) {
+        fields.add(member);
+      }
+    }
+
+    if (methods.length > 0) {
+      writeln('<h3>Methods</h3>');
+      for (final method in methods) docMethod(type, method);
+    }
+
+    if (fields.length > 0) {
+      writeln('<h3>Fields</h3>');
+      for (final field in fields) docField(type, field);
+    }
+  }
+
+  /**
+   * Documents the [method] in type [type]. Handles all kinds of methods
+   * including getters, setters, and constructors.
+   */
+  docMethod(Type type, MethodMember method, [String constructorName = null]) {
+    _totalMembers++;
+    _currentMember = method;
+
+    writeln('<div class="method"><h4 id="${memberAnchor(method)}">');
+
+    if (includeSource) {
+      writeln('<span class="show-code">Code</span>');
+    }
+
+    if (method.isStatic && !type.isTop) {
+      write('static ');
+    }
+
+    if (method.isConstructor) {
+      write(method.isConst ? 'const ' : 'new ');
+    }
+
+    if (constructorName == null) {
+      annotateType(type, method.returnType);
+    }
+
+    // Translate specially-named methods: getters, setters, operators.
+    var name = method.name;
+    if (name.startsWith('get:')) {
+      // Getter.
+      name = 'get ${name.substring(4)}';
+    } else if (name.startsWith('set:')) {
+      // Setter.
+      name = 'set ${name.substring(4)}';
+    } else {
+      // See if it's an operator.
+      name = TokenKind.rawOperatorFromMethod(name);
+      if (name == null) {
+        name = method.name;
+      } else {
+        name = 'operator $name';
+      }
+    }
+
+    write('<strong>$name</strong>');
+
+    // Named constructors.
+    if (constructorName != null && constructorName != '') {
+      write('.');
+      write(constructorName);
+    }
+
+    docParamList(type, method);
+
+    write(''' <a class="anchor-link" href="#${memberAnchor(method)}"
+              title="Permalink to ${typeName(type)}.$name">#</a>''');
+    writeln('</h4>');
+
+    docCode(method.span, getMethodComment(method), showCode: true);
+
+    writeln('</div>');
+  }
+
+  /** Documents the field [field] of type [type]. */
+  docField(Type type, FieldMember field) {
+    _totalMembers++;
+    _currentMember = field;
+
+    writeln('<div class="field"><h4 id="${memberAnchor(field)}">');
+
+    if (includeSource) {
+      writeln('<span class="show-code">Code</span>');
+    }
+
+    if (field.isStatic && !type.isTop) {
+      write('static ');
+    }
+
+    if (field.isFinal) {
+      write('final ');
+    } else if (field.type.name == 'Dynamic') {
+      write('var ');
+    }
+
+    annotateType(type, field.type);
+    write(
+        '''
+        <strong>${field.name}</strong> <a class="anchor-link"
+            href="#${memberAnchor(field)}"
+            title="Permalink to ${typeName(type)}.${field.name}">#</a>
         </h4>
-        </div>
         ''');
+
+    docCode(field.span, getFieldComment(field), showCode: true);
+    writeln('</div>');
+  }
+
+  docParamList(Type enclosingType, MethodMember member) {
+    write('(');
+    bool first = true;
+    bool inOptionals = false;
+    for (final parameter in member.parameters) {
+      if (!first) write(', ');
+
+      if (!inOptionals && parameter.isOptional) {
+        write('[');
+        inOptionals = true;
+      }
+
+      annotateType(enclosingType, parameter.type, parameter.name);
+
+      // Show the default value for named optional parameters.
+      if (parameter.isOptional && parameter.hasDefaultValue) {
+        write(' = ');
+        // TODO(rnystrom): Using the definition text here is a bit cheap.
+        // We really should be pretty-printing the AST so that if you have:
+        //   foo([arg = 1 + /* comment */ 2])
+        // the docs should just show:
+        //   foo([arg = 1 + 2])
+        // For now, we'll assume you don't do that.
+        write(parameter.definition.value.span.text);
+      }
+
+      first = false;
+    }
+
+    if (inOptionals) write(']');
+    write(')');
+  }
+
+  /**
+   * Documents the code contained within [span] with [comment]. If [showCode]
+   * is `true` (and [includeSource] is set), also includes the source code.
+   */
+  docCode(SourceSpan span, String comment, [bool showCode = false]) {
+    writeln('<div class="doc">');
+    if (comment != null) {
+      writeln(md.markdownToHtml(comment));
+    }
+
+    if (includeSource && showCode) {
+      writeln('<pre class="source">');
+      write(formatCode(span));
+      writeln('</pre>');
+    }
+
+    writeln('</div>');
+  }
+
+  /** Get the doc comment associated with the given type. */
+  String getTypeComment(Type type) => _comments.find(type.span);
+
+  /** Get the doc comment associated with the given method. */
+  String getMethodComment(MethodMember method) => _comments.find(method.span);
+
+  /** Get the doc comment associated with the given field. */
+  String getFieldComment(FieldMember field) => _comments.find(field.span);
+
+  /**
+   * Creates a hyperlink. Handles turning the [href] into an appropriate
+   * relative path from the current file.
+   */
+  String a(String href, String contents, [String class]) {
+    final css = class == null ? '' : ' class="$class"';
+    return '<a href="${relativePath(href)}"$css>$contents</a>';
+  }
+
+  /**
+   * Writes a type annotation for the given type and (optional) parameter name.
+   */
+  annotateType(Type enclosingType, Type type, [String paramName = null]) {
+    // Don't bother explicitly displaying Dynamic.
+    if (type.isVar) {
+      if (paramName !== null) write(paramName);
+      return;
+    }
+
+    // For parameters, handle non-typedefed function types.
+    if (paramName !== null) {
+      final call = type.getCallMethod();
+      if (call != null) {
+        annotateType(enclosingType, call.returnType);
+        write(paramName);
+
+        docParamList(enclosingType, call);
+        return;
+      }
+    }
+
+    linkToType(enclosingType, type);
+
+    write(' ');
+    if (paramName !== null) write(paramName);
+  }
+
+  /** Writes a link to a human-friendly string representation for a type. */
+  linkToType(Type enclosingType, Type type) {
+    if (type is ParameterType) {
+      // If we're using a type parameter within the body of a generic class then
+      // just link back up to the class.
+      write(a(typeUrl(enclosingType), type.name));
+      return;
+    }
+
+    // Link to the type.
+    // Use .genericType to avoid writing the <...> here.
+    write(a(typeUrl(type), type.genericType.name));
+
+    // See if it's a generic type.
+    if (type.isGeneric) {
+      // TODO(rnystrom): This relies on a weird corner case of frog. Currently,
+      // the only time we get into this case is when we have a "raw" generic
+      // that's been instantiated with Dynamic for all type arguments. It's kind
+      // of strange that frog works that way, but we take advantage of it to
+      // show raw types without any type arguments.
+      return;
+    }
+
+    // See if it's an instantiation of a generic type.
+    final typeArgs = type.typeArgsInOrder;
+    if (typeArgs != null) {
+      write('&lt;');
+      bool first = true;
+      for (final arg in typeArgs) {
+        if (!first) write(', ');
+        first = false;
+        linkToType(enclosingType, arg);
+      }
+      write('&gt;');
+    }
+  }
+
+  /** Creates a linked cross reference to [type]. */
+  typeReference(Type type) {
+    // TODO(rnystrom): Do we need to handle ParameterTypes here like
+    // annotation() does?
+    return a(typeUrl(type), typeName(type), class: 'crossref');
+  }
+
+  /** Generates a human-friendly string representation for a type. */
+  typeName(Type type, [bool showBounds = false]) {
+    // See if it's a generic type.
+    if (type.isGeneric) {
+      final typeParams = [];
+      for (final typeParam in type.genericType.typeParameters) {
+        if (showBounds &&
+            (typeParam.extendsType != null) &&
+            !typeParam.extendsType.isObject) {
+          final bound = typeName(typeParam.extendsType, showBounds: true);
+          typeParams.add('${typeParam.name} extends $bound');
+        } else {
+          typeParams.add(typeParam.name);
+        }
+      }
+
+      final params = Strings.join(typeParams, ', ');
+      return '${type.name}&lt;$params&gt;';
+    }
+
+    // See if it's an instantiation of a generic type.
+    final typeArgs = type.typeArgsInOrder;
+    if (typeArgs != null) {
+      final args = Strings.join(map(typeArgs, (arg) => typeName(arg)), ', ');
+      return '${type.genericType.name}&lt;$args&gt;';
+    }
+
+    // Regular type.
+    return type.name;
+  }
+
+  /**
+   * Takes a string of Dart code and turns it into sanitized HTML.
+   */
+  formatCode(SourceSpan span) {
+    // Remove leading indentation to line up with first line.
+    final column = getSpanColumn(span);
+    final lines = span.text.split('\n');
+    // TODO(rnystrom): Dirty hack.
+    for (final i = 1; i < lines.length; i++) {
+      lines[i] = unindent(lines[i], column);
+    }
+
+    final code = Strings.join(lines, '\n');
+
+    // Syntax highlight.
+    return classifySource(new SourceFile('', code));
+  }
+
+  /**
+   * This will be called whenever a doc comment hits a `[name]` in square
+   * brackets. It will try to figure out what the name refers to and link or
+   * style it appropriately.
+   */
+  md.Node resolveNameReference(String name) {
+    makeLink(String href) {
+      final anchor = new md.Element.text('a', name);
+      anchor.attributes['href'] = relativePath(href);
+      anchor.attributes['class'] = 'crossref';
+      return anchor;
+    }
+
+    findMember(Type type) {
+      final member = type.members[name];
+      if (member == null) return null;
+
+      // Special case: if the member we've resolved is a property (i.e. it wraps
+      // a getter and/or setter then *that* member itself won't be on the docs,
+      // just the getter or setter will be. So pick one of those to link to.
+      if (member.isProperty) {
+        return member.canGet ? member.getter : member.setter;
+      }
+
+      return member;
+    }
+
+    // See if it's a parameter of the current method.
+    if (_currentMember != null) {
+      for (final parameter in _currentMember.parameters) {
+        if (parameter.name == name) {
+          final element = new md.Element.text('span', name);
+          element.attributes['class'] = 'param';
+          return element;
+        }
+      }
+    }
+
+    // See if it's another member of the current type.
+    if (_currentType != null) {
+      final member = findMember(_currentType);
+      if (member != null) {
+        return makeLink(memberUrl(member));
+      }
+    }
+
+    // See if it's another type in the current library.
+    if (_currentLibrary != null) {
+      final type = _currentLibrary.types[name];
+      if (type != null) {
+        return makeLink(typeUrl(type));
+      }
+
+      // See if it's a top-level member in the current library.
+      final member = findMember(_currentLibrary.topType);
+      if (member != null) {
+        return makeLink(memberUrl(member));
+      }
+    }
+
+    // TODO(rnystrom): Should also consider:
+    // * Names imported by libraries this library imports.
+    // * Type parameters of the enclosing type.
+
+    return new md.Element.text('code', name);
+  }
+
+  // TODO(rnystrom): Move into SourceSpan?
+  int getSpanColumn(SourceSpan span) {
+    final line = span.file.getLine(span.start);
+    return span.file.getColumn(line, span.start);
   }
 }
-
-docType(Type type) {
-  _totalTypes++;
-  _currentType = type;
-
-  startFile(typeUrl(type));
-
-  final typeTitle = '${type.isClass ? "Class" : "Interface"} ${typeName(type)}';
-  writeHeader('Library ${type.library.name} / $typeTitle');
-  writeln(
-      '''
-      <h1>${a(libraryUrl(type.library),
-            "Library <strong>${type.library.name}</strong>")}</h1>
-      <h2>${type.isClass ? "Class" : "Interface"}
-          <strong>${typeName(type, showBounds: true)}</strong></h2>
-      ''');
-
-  docInheritance(type);
-  docCode(type.span, _runDocumenters(type, _typeDocumenters));
-  docConstructors(type);
-  docMembers(type);
-
-  writeFooter();
-  endFile();
-}
-
-void docMembers(Type type) {
-  // Collect the different kinds of members.
-  final methods = [];
-  final fields = [];
-
-  for (final member in orderByName(type.members)) {
-    if (member.name.startsWith('_')) continue;
-
-    if (member.isProperty) {
-      if (member.canGet) methods.add(member.getter);
-      if (member.canSet) methods.add(member.setter);
-    } else if (member.isMethod) {
-      methods.add(member);
-    } else if (member.isField) {
-      fields.add(member);
-    }
-  }
-
-  if (methods.length > 0) {
-    writeln('<h3>Methods</h3>');
-    for (final method in methods) docMethod(type, method);
-  }
-
-  if (fields.length > 0) {
-    writeln('<h3>Fields</h3>');
-    for (final field in fields) docField(type, field);
-  }
-}
-
-/** Document the superclass, superinterfaces and factory of [Type]. */
-docInheritance(Type type) {
-  final isSubclass = (type.parent != null) && !type.parent.isObject;
-
-  Type factory;
-  if (type.definition is TypeDefinition) {
-    TypeDefinition definition = type.definition;
-    if (definition.factoryType != null) {
-      factory = definition.factoryType.type;
-    }
-  }
-
-  if (isSubclass ||
-      (type.interfaces != null && type.interfaces.length > 0) ||
-      (factory != null)) {
-    writeln('<p>');
-
-    if (isSubclass) {
-      write('Extends ${typeReference(type.parent)}. ');
-    }
-
-    if (type.interfaces != null && type.interfaces.length > 0) {
-      var interfaceStr = joinWithCommas(map(type.interfaces, typeReference));
-      write('Implements ${interfaceStr}. ');
-    }
-
-    if (factory != null) {
-      write('Has factory class ${typeReference(factory)}.');
-    }
-  }
-}
-
-/** Document the constructors for [Type], if any. */
-docConstructors(Type type) {
-  final names = type.constructors.getKeys().filter(
-    (name) => !name.startsWith('_'));
-
-  if (names.length > 0) {
-    writeln('<h3>Constructors</h3>');
-    names.sort((x, y) => x.toUpperCase().compareTo(y.toUpperCase()));
-
-    for (final name in names) {
-      docMethod(type, type.constructors[name], constructorName: name);
-    }
-  }
-}
-
-/**
- * Documents the [method] in type [type]. Handles all kinds of methods
- * including getters, setters, and constructors.
- */
-docMethod(Type type, MethodMember method, [String constructorName = null]) {
-  _totalMembers++;
-  _currentMember = method;
-
-  writeln('<div class="method"><h4 id="${memberAnchor(method)}">');
-
-  if (includeSource) {
-    writeln('<span class="show-code">Code</span>');
-  }
-
-  if (method.isStatic && !type.isTop) {
-    write('static ');
-  }
-
-  if (method.isConstructor) {
-    write(method.isConst ? 'const ' : 'new ');
-  }
-
-  if (constructorName == null) {
-    annotateType(type, method.returnType);
-  }
-
-  // Translate specially-named methods: getters, setters, operators.
-  var name = method.name;
-  if (name.startsWith('get:')) {
-    // Getter.
-    name = 'get ${name.substring(4)}';
-  } else if (name.startsWith('set:')) {
-    // Setter.
-    name = 'set ${name.substring(4)}';
-  } else {
-    // See if it's an operator.
-    name = TokenKind.rawOperatorFromMethod(name);
-    if (name == null) {
-      name = method.name;
-    } else {
-      name = 'operator $name';
-    }
-  }
-
-  write('<strong>$name</strong>');
-
-  // Named constructors.
-  if (constructorName != null && constructorName != '') {
-    write('.');
-    write(constructorName);
-  }
-
-  docParamList(type, method);
-
-  write(''' <a class="anchor-link" href="#${memberAnchor(method)}"
-            title="Permalink to ${typeName(type)}.$name">#</a>''');
-  writeln('</h4>');
-
-  docCode(method.span, _runDocumenters(method, _methodDocumenters),
-      showCode: true);
-
-  writeln('</div>');
-}
-
-docParamList(Type enclosingType, MethodMember member) {
-  write('(');
-  bool first = true;
-  bool inOptionals = false;
-  for (final parameter in member.parameters) {
-    if (!first) write(', ');
-
-    if (!inOptionals && parameter.isOptional) {
-      write('[');
-      inOptionals = true;
-    }
-
-    annotateType(enclosingType, parameter.type, parameter.name);
-
-    // Show the default value for named optional parameters.
-    if (parameter.isOptional && parameter.hasDefaultValue) {
-      write(' = ');
-      // TODO(rnystrom): Using the definition text here is a bit cheap.
-      // We really should be pretty-printing the AST so that if you have:
-      //   foo([arg = 1 + /* comment */ 2])
-      // the docs should just show:
-      //   foo([arg = 1 + 2])
-      // For now, we'll assume you don't do that.
-      write(parameter.definition.value.span.text);
-    }
-
-    first = false;
-  }
-
-  if (inOptionals) write(']');
-  write(')');
-}
-
-/** Documents the field [field] of type [type]. */
-docField(Type type, FieldMember field) {
-  _totalMembers++;
-  _currentMember = field;
-
-  writeln('<div class="field"><h4 id="${memberAnchor(field)}">');
-
-  if (includeSource) {
-    writeln('<span class="show-code">Code</span>');
-  }
-
-  if (field.isStatic && !type.isTop) {
-    write('static ');
-  }
-
-  if (field.isFinal) {
-    write('final ');
-  } else if (field.type.name == 'Dynamic') {
-    write('var ');
-  }
-
-  annotateType(type, field.type);
-  write(
-      '''
-      <strong>${field.name}</strong> <a class="anchor-link"
-          href="#${memberAnchor(field)}"
-          title="Permalink to ${typeName(type)}.${field.name}">#</a>
-      </h4>
-      ''');
-
-  docCode(field.span, _runDocumenters(field, _fieldDocumenters),
-      showCode: true);
-  writeln('</div>');
-}
-
-/**
- * Creates a hyperlink. Handles turning the [href] into an appropriate relative
- * path from the current file.
- */
-String a(String href, String contents, [String class]) {
-  final css = class == null ? '' : ' class="$class"';
-  return '<a href="${relativePath(href)}"$css>$contents</a>';
-}
-
-/** Generates a human-friendly string representation for a type. */
-typeName(Type type, [bool showBounds = false]) {
-  // See if it's a generic type.
-  if (type.isGeneric) {
-    final typeParams = [];
-    for (final typeParam in type.genericType.typeParameters) {
-      if (showBounds &&
-          (typeParam.extendsType != null) &&
-          !typeParam.extendsType.isObject) {
-        final bound = typeName(typeParam.extendsType, showBounds: true);
-        typeParams.add('${typeParam.name} extends $bound');
-      } else {
-        typeParams.add(typeParam.name);
-      }
-    }
-
-    final params = Strings.join(typeParams, ', ');
-    return '${type.name}&lt;$params&gt;';
-  }
-
-  // See if it's an instantiation of a generic type.
-  final typeArgs = type.typeArgsInOrder;
-  if (typeArgs != null) {
-    final args = Strings.join(map(typeArgs, typeName), ', ');
-    return '${type.genericType.name}&lt;$args&gt;';
-  }
-
-  // Regular type.
-  return type.name;
-}
-
-/** Writes a link to a human-friendly string representation for a type. */
-linkToType(Type enclosingType, Type type) {
-  if (type is ParameterType) {
-    // If we're using a type parameter within the body of a generic class then
-    // just link back up to the class.
-    write(a(typeUrl(enclosingType), type.name));
-    return;
-  }
-
-  // Link to the type.
-  // Use .genericType to avoid writing the <...> here.
-  write(a(typeUrl(type), type.genericType.name));
-
-  // See if it's a generic type.
-  if (type.isGeneric) {
-    // TODO(rnystrom): This relies on a weird corner case of frog. Currently,
-    // the only time we get into this case is when we have a "raw" generic
-    // that's been instantiated with Dynamic for all type arguments. It's kind
-    // of strange that frog works that way, but we take advantage of it to
-    // show raw types without any type arguments.
-    return;
-  }
-
-  // See if it's an instantiation of a generic type.
-  final typeArgs = type.typeArgsInOrder;
-  if (typeArgs != null) {
-    write('&lt;');
-    bool first = true;
-    for (final arg in typeArgs) {
-      if (!first) write(', ');
-      first = false;
-      linkToType(enclosingType, arg);
-    }
-    write('&gt;');
-  }
-}
-
-/** Creates a linked cross reference to [type]. */
-typeReference(Type type) {
-  // TODO(rnystrom): Do we need to handle ParameterTypes here like
-  // annotation() does?
-  return a(typeUrl(type), typeName(type), class: 'crossref');
-}
-
-/**
- * Writes a type annotation for the given type and (optional) parameter name.
- */
-annotateType(Type enclosingType, Type type, [String paramName = null]) {
-  // Don't bother explicitly displaying Dynamic.
-  if (type.isVar) {
-    if (paramName !== null) write(paramName);
-    return;
-  }
-
-  // For parameters, handle non-typedefed function types.
-  if (paramName !== null) {
-    final call = type.getCallMethod();
-    if (call != null) {
-      annotateType(enclosingType, call.returnType);
-      write(paramName);
-
-      docParamList(enclosingType, call);
-      return;
-    }
-  }
-
-  linkToType(enclosingType, type);
-
-  write(' ');
-  if (paramName !== null) write(paramName);
-}
-
-
-/**
- * This will be called whenever a doc comment hits a `[name]` in square
- * brackets. It will try to figure out what the name refers to and link or
- * style it appropriately.
- */
-md.Node resolveNameReference(String name) {
-  makeLink(String href) {
-    final anchor = new md.Element.text('a', name);
-    anchor.attributes['href'] = relativePath(href);
-    anchor.attributes['class'] = 'crossref';
-    return anchor;
-  }
-
-  findMember(Type type) {
-    final member = type.members[name];
-    if (member == null) return null;
-
-    // Special case: if the member we've resolved is a property (i.e. it wraps
-    // a getter and/or setter then *that* member itself won't be on the docs,
-    // just the getter or setter will be. So pick one of those to link to.
-    if (member.isProperty) {
-      return member.canGet ? member.getter : member.setter;
-    }
-
-    return member;
-  }
-
-  // See if it's a parameter of the current method.
-  if (_currentMember != null) {
-    for (final parameter in _currentMember.parameters) {
-      if (parameter.name == name) {
-        final element = new md.Element.text('span', name);
-        element.attributes['class'] = 'param';
-        return element;
-      }
-    }
-  }
-
-  // See if it's another member of the current type.
-  if (_currentType != null) {
-    final member = findMember(_currentType);
-    if (member != null) {
-      return makeLink(memberUrl(member));
-    }
-  }
-
-  // See if it's another type in the current library.
-  if (_currentLibrary != null) {
-    final type = _currentLibrary.types[name];
-    if (type != null) {
-      return makeLink(typeUrl(type));
-    }
-
-    // See if it's a top-level member in the current library.
-    final member = findMember(_currentLibrary.topType);
-    if (member != null) {
-      return makeLink(memberUrl(member));
-    }
-  }
-
-  // TODO(rnystrom): Should also consider:
-  // * Names imported by libraries this library imports.
-  // * Type parameters of the enclosing type.
-
-  return new md.Element.text('code', name);
-}
-
-/**
- * Documents the code contained within [span]. Will include the previous
- * Dartdoc associated with that span if found, and will include the syntax
- * highlighted code itself if desired.
- */
-docCode(SourceSpan span, String extraMarkdown, [bool showCode = false]) {
-  if (span == null) return;
-
-  writeln('<div class="doc">');
-  final comment = findComment(span);
-  if (comment != null) {
-    writeln(md.markdownToHtml('${comment}\n\n${extraMarkdown}'));
-  } else {
-    writeln(md.markdownToHtml(extraMarkdown));
-  }
-
-  if (includeSource && showCode) {
-    writeln('<pre class="source">');
-    write(formatCode(span));
-    writeln('</pre>');
-  }
-
-  writeln('</div>');
-}
-
-/** Finds the doc comment preceding the given source span, if there is one. */
-findComment(SourceSpan span) => findCommentInFile(span.file, span.start);
-
-/** Finds the doc comment preceding the given source span, if there is one. */
-findCommentInFile(SourceFile file, int position) {
-  // Get the doc comments for this file.
-  final fileComments = _comments.putIfAbsent(file.filename,
-    () => parseDocComments(file));
-
-  return fileComments[position];
-}
-
-parseDocComments(SourceFile file) {
-  final comments = new Map<int, String>();
-
-  final tokenizer = new Tokenizer(file, false);
-  var lastComment = null;
-
-  while (true) {
-    final token = tokenizer.next();
-    if (token.kind == TokenKind.END_OF_FILE) break;
-
-    if (token.kind == TokenKind.COMMENT) {
-      final text = token.text;
-      if (text.startsWith('/**')) {
-        // Remember that we've encountered a doc comment.
-        lastComment = stripComment(token.text);
-      } else if (text.startsWith('///')) {
-        var line = text.substring(3, text.length);
-        // Allow a leading space.
-        if (line.startsWith(' ')) line = line.substring(1, text.length);
-        if (lastComment == null) {
-          lastComment = line;
-        } else {
-          lastComment = '$lastComment$line';
-        }
-      }
-    } else if (token.kind == TokenKind.WHITESPACE) {
-      // Ignore whitespace tokens.
-    } else if (token.kind == TokenKind.HASH) {
-      // Look for #library() to find the library comment.
-      final next = tokenizer.next();
-      if ((lastComment != null) && (next.kind == TokenKind.LIBRARY)) {
-        comments[_libraryDoc] = lastComment;
-        lastComment = null;
-      }
-    } else {
-      if (lastComment != null) {
-        // We haven't attached the last doc comment to something yet, so stick
-        // it to this token.
-        comments[token.start] = lastComment;
-        lastComment = null;
-      }
-    }
-  }
-
-  return comments;
-}
-
-/**
- * Takes a string of Dart code and turns it into sanitized HTML.
- */
-formatCode(SourceSpan span) {
-  // Remove leading indentation to line up with first line.
-  final column = getSpanColumn(span);
-  final lines = span.text.split('\n');
-  // TODO(rnystrom): Dirty hack.
-  for (final i = 1; i < lines.length; i++) {
-    lines[i] = unindent(lines[i], column);
-  }
-
-  final code = Strings.join(lines, '\n');
-
-  // Syntax highlight.
-  return classifySource(new SourceFile('', code));
-}
-
-// TODO(rnystrom): Move into SourceSpan?
-int getSpanColumn(SourceSpan span) {
-  final line = span.file.getLine(span.start);
-  return span.file.getColumn(line, span.start);
-}
-
-/**
- * Pulls the raw text out of a doc comment (i.e. removes the comment
- * characters).
- */
-stripComment(comment) {
-  StringBuffer buf = new StringBuffer();
-
-  for (final line in comment.split('\n')) {
-    line = line.trim();
-    if (line.startsWith('/**')) line = line.substring(3, line.length);
-    if (line.endsWith('*/')) line = line.substring(0, line.length - 2);
-    line = line.trim();
-    if (line.startsWith('* ')) {
-      line = line.substring(2, line.length);
-    } else if (line.startsWith('*')) {
-      line = line.substring(1, line.length);
-    }
-
-    buf.add(line);
-    buf.add('\n');
-  }
-
-  return buf.toString();
-}
-
-/** Register a callback to add additional documentation to a type. */
-addTypeDocumenter(TypeDocumenter fn) => _typeDocumenters.add(fn);
-
-/** Register a callback to add additional documentation to a method. */
-addMethodDocumenter(MethodDocumenter fn) => _methodDocumenters.add(fn);
-
-/** Register a callback to add additional documentation to a field. */
-addFieldDocumenter(FieldDocumenter fn) => _fieldDocumenters.add(fn);