Clean up:

lib/src/html_renderer.dart

 // Copyright (c) 2012, 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 markdown.html_renderer;
+library markdown.src.html_renderer;
 
 import 'ast.dart';
 import 'document.dart';
 import 'inline_parser.dart';
 
 /// Converts the given string of markdown to HTML.
-String markdownToHtml(String markdown, {List<InlineSyntax> inlineSyntaxes,
-    Resolver linkResolver, Resolver imageLinkResolver,
+String markdownToHtml(String markdown,
+    {List<InlineSyntax> inlineSyntaxes,
+    Resolver linkResolver,
+    Resolver imageLinkResolver,
     bool inlineOnly: false}) {
   var document = new Document(
       inlineSyntaxes: inlineSyntaxes,
       imageLinkResolver: imageLinkResolver,
       linkResolver: linkResolver);
 
-  if (inlineOnly) {
-    return renderToHtml(document.parseInline(markdown));
-  } else {
-    // Replace windows line endings with unix line endings, and split.
-    var lines = markdown.replaceAll('\r\n', '\n').split('\n');
-    document.parseRefLinks(lines);
-    var blocks = document.parseLines(lines);
-    return renderToHtml(blocks);
-  }
+  if (inlineOnly) return renderToHtml(document.parseInline(markdown));
+
+  // Replace windows line endings with unix line endings, and split.
+  var lines = markdown.replaceAll('\r\n', '\n').split('\n');
+  document.parseRefLinks(lines);
+
+  return renderToHtml(document.parseLines(lines));
 }
 
 String renderToHtml(List<Node> nodes) => new HtmlRenderer().render(nodes);
 
 /// Translates a parsed AST to HTML.
 class HtmlRenderer implements NodeVisitor {
-  static final _BLOCK_TAGS = new RegExp(
-      'blockquote|h1|h2|h3|h4|h5|h6|hr|p|pre');
+  static final _blockTags = new RegExp('blockquote|h1|h2|h3|h4|h5|h6|hr|p|pre');
 
   StringBuffer buffer;
 
   HtmlRenderer();
 
   String render(List<Node> nodes) {
     buffer = new StringBuffer();
 
     for (final node in nodes) node.accept(this);
 
     return buffer.toString();
   }
 
   void visitText(Text text) {
     buffer.write(text.text);
   }
 
   bool visitElementBefore(Element element) {
     // Hackish. Separate block-level elements with newlines.
-    if (!buffer.isEmpty && _BLOCK_TAGS.firstMatch(element.tag) != null) {
+    if (!buffer.isEmpty && _blockTags.firstMatch(element.tag) != null) {
       buffer.write('\n');
     }
 
     buffer.write('<${element.tag}');
 
     // Sort the keys so that we generate stable output.
-    final attributeNames = element.attributes.keys.toList();
+    var attributeNames = element.attributes.keys.toList();
     attributeNames.sort((a, b) => a.compareTo(b));
-    for (final name in attributeNames) {
+
+    for (var name in attributeNames) {
       buffer.write(' $name="${element.attributes[name]}"');
     }
 
     if (element.isEmpty) {
       // Empty element like <hr/>.
       buffer.write(' />');
       return false;
     } else {
       buffer.write('>');
       return true;
     }
   }
 
   void visitElementAfter(Element element) {
     buffer.write('</${element.tag}>');
   }
 }