Add secret option "live" which compiles more frequently.

dart/site/try/src/interaction_manager.dart

 // Copyright (c) 2014, 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 trydart.interaction_manager;
 
 import 'dart:html';
 
 import 'dart:convert' show
     JSON;
@@ skipping 76 matching lines @@
 const Duration HEARTBEAT_INTERVAL = const Duration(milliseconds: 50);
 
 /// Determines how frequently "project" files are saved.  The time is measured
 /// from the time of last modification.
 const Duration SAVE_INTERVAL = const Duration(seconds: 5);
 
 /// Determines how frequently the compiler is invoked.  The time is measured
 /// from the time of last modification.
 const Duration COMPILE_INTERVAL = const Duration(seconds: 1);
 
+/// Determines how frequently the compiler is invoked in "live" mode.  The time
+/// is measured from the time of last modification.
+const Duration LIVE_COMPILE_INTERVAL = const Duration(seconds: 0);
+
 /// Determines if a compilation is slow.  The time is measured from the last
 /// compilation started.  If a compilation is slow, progress information is
 /// displayed to the user, but the console is untouched if the compilation
 /// finished quickly.  The purpose is to reduce flicker in the UI.
 const Duration SLOW_COMPILE = const Duration(seconds: 1);
 
 /**
  * UI interaction manager for the entire application.
  */
 abstract class InteractionManager {
@@ skipping 95 matching lines @@
   Completer<String> completeSaveOperation;
 
   bool shouldClearConsole = false;
 
   Element compilerConsole;
 
   bool isFirstCompile = true;
 
   final Set<AnchorElement> oldDiagnostics = new Set<AnchorElement>();
 
+  final Duration compileInterval = settings.live.value
+      ? LIVE_COMPILE_INTERVAL
+      : COMPILE_INTERVAL;
+
   InteractionContext()
       : super.internal() {
     state = new InitialState(this);
     heartbeat = new Timer.periodic(HEARTBEAT_INTERVAL, onHeartbeat);
   }
 
   void onInput(Event event) => state.onInput(event);
 
   void onKeyUp(KeyboardEvent event) => state.onKeyUp(event);
 
@@ skipping 340 matching lines @@
     if (context.unitsToSave.isEmpty &&
         context.saveTimer.elapsed > SAVE_INTERVAL) {
       context.saveTimer
           ..stop()
           ..reset();
       context.unitsToSave.addAll(context.modifiedUnits);
       context.modifiedUnits.clear();
       saveUnits();
     }
     if (!settings.compilationPaused &&
-        context.compileTimer.elapsed > COMPILE_INTERVAL) {
+        context.compileTimer.elapsed > context.compileInterval) {
       if (startCompilation()) {
         context.compileTimer
             ..stop()
             ..reset();
       }
     }
 
     if (context.elapsedCompilationTime.elapsed > SLOW_COMPILE) {
       if (context.compilerConsole.parent == null) {
         outputDiv.append(context.compilerConsole);
@@ skipping 605 matching lines @@
 bool isCompilerStageMarker(String message) {
   return
       message.startsWith('Package root is ') ||
       message.startsWith('Compiling ') ||
       message == "Resolving..." ||
       message.startsWith('Resolved ') ||
       message == "Inferring types..." ||
       message == "Compiling..." ||
       message.startsWith('Compiled ');
 }