work in progress: observable implementation using detailed change records

lib/src/emitters.dart

Index: lib/src/emitters.dart
diff --git a/lib/src/emitters.dart b/lib/src/emitters.dart
index 0093f88e543aa1d7fd445b13befe3aabfb1d120f..19d252bbc86ac4a620c9e68bdea48203fd1fa5d2 100644
--- a/lib/src/emitters.dart
+++ b/lib/src/emitters.dart
@@ -351,7 +351,7 @@ class WebComponentEmitter extends RecursiveEmitter {
           : info.tagName.replaceAll(new RegExp('[-./]'), '_');
       printer.add(codegen.header(info.declaringFile.path, libraryName));
 
-      // Add exisitng import, export, and part directives.
+      // Add existing import, export, and part directives.
       for (var directive in codeInfo.directives) {
         printer.add(codegen.directiveText(directive, info, pathInfo));
       }
@@ -421,7 +421,7 @@ class MainPageEmitter extends RecursiveEmitter {
         ? codeInfo.libraryName : _fileInfo.libraryName;
     printer.add(codegen.header(_fileInfo.path, libraryName));
 
-    // Add exisitng import, export, and part directives.
+    // Add existing import, export, and part directives.
     for (var directive in codeInfo.directives) {
       printer.add(codegen.directiveText(directive, _fileInfo, pathInfo));
     }
@@ -437,6 +437,23 @@ class MainPageEmitter extends RecursiveEmitter {
   }
 }
 
+/** Emits a .dart file using the [DartCodeInfo]. */
+String emitDartFile(FileInfo fileInfo, PathInfo pathInfo) {
+  var printer = new CodePrinter();
+
+  // Inject library name if not pressent.
+  var codeInfo = fileInfo.userCode;
+  var libraryName = codeInfo.libraryName;
+  printer.add(codegen.header(fileInfo.path, codeInfo.libraryName));
+
+  // Add existing import, export, and part directives.
+  for (var directive in codeInfo.directives) {
+    printer.add(codegen.directiveText(directive, fileInfo, pathInfo));
+  }
+  printer.addRaw(codeInfo.code);
+  return printer.formatString();
+}
+
 /** Clears all fields in [declarations]. */
 String _clearFields(Declarations declarations) {
   if (declarations.declarations.isEmpty) return '';