From af894366d3a5144574468aa5dd74c68ac4fd3940 Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@hashcollision.org>
Date: Fri, 8 Mar 2013 17:38:17 -0700
Subject: [PATCH] reset appears to be doing something.

---
 whalesong/js-assembler/runtime-src/runtime.js | 21 +++++++++++++------
 whalesong/repl-prototype/htdocs/repl.js       | 15 +++++++++----
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/whalesong/js-assembler/runtime-src/runtime.js b/whalesong/js-assembler/runtime-src/runtime.js
index e7c09b1..4364008 100644
--- a/whalesong/js-assembler/runtime-src/runtime.js
+++ b/whalesong/js-assembler/runtime-src/runtime.js
@@ -245,6 +245,18 @@
     // The MACHINE
 
     var Machine = function() {
+        // These are the modules that have been installed.  They are not
+        // necessarily invoked yet.
+        this.installedModules = {};  // String -> (-> ModuleRecord)
+        this.reset();
+    };
+
+
+    // Resets the state of the machine.  Almost all of the system's
+    // state is reset, except the installedModules, which should
+    // persist as an optimization to reduce loading code over and
+    // over.
+    Machine.prototype.reset = function() {
 	this.cbt = STACK_LIMIT_ESTIMATE;  // calls before trampoline
 	this.v = void(0);         // value register
 	this.p = void(0);        // procedure register
@@ -252,9 +264,9 @@
 	this.e = [];                // environment
 	this.c = [];            // control: Arrayof (U Frame CallFrame PromptFrame)
 	this.running = false;
-        // These are the modules that have been installed.  They are not
-        // necessarily invoked yet.
-        this.installedModules = {};  // String -> (-> ModuleRecord)
+
+        // We do not initialize installedModules here because
+        // we want that to persist.
 
         // These are the modules that have been invoked.
 	this.modules = {};     // String -> ModuleRecord
@@ -313,8 +325,6 @@
 	    'maxNumBouncesBeforeYield': 2000, // self-adjusting
 
 	    'currentPrint': defaultCurrentPrint
-
-
 	};
         this.globals = {};
 	this.primitives = Primitives;
@@ -322,7 +332,6 @@
         this.breakScheduled = false;
     };
 
-
     // Schedule a break the next time the trampoline begins.
     Machine.prototype.scheduleBreak = function() {
         this.breakScheduled = true;
diff --git a/whalesong/repl-prototype/htdocs/repl.js b/whalesong/repl-prototype/htdocs/repl.js
index 457b8ec..71606f3 100644
--- a/whalesong/repl-prototype/htdocs/repl.js
+++ b/whalesong/repl-prototype/htdocs/repl.js
@@ -8,22 +8,27 @@ $(document).ready(function() {
     var resetButton = $("#reset");
     breakButton.hide();
     breakButton.click(function() { interruptEvaluation(); });
-    resetButton.click(function() { setupMachine(); });
+    resetButton.click(function() { output.empty(); setupMachine(); });
 
 
     var M;
 
+    var sendOutputToBottom = function() {
+        output.get(0).scrollTop = output.get(0).scrollHeight;
+    };
+
+    
     var setupMachine = function() { 
         M = plt.runtime.currentMachine;
-
+        M.reset();
         // We configure output to send it to the "output" DOM node.
         M.params.currentDisplayer = function(MACHINE, domNode) {
             $(domNode).appendTo(output);
-            output.get(0).scrollTop = output.get(0).scrollHeight;
+            sendOutputToBottom();
         };
         M.params.currentErrorDisplayer = function(MACHINE, domNode) {
             $(domNode).css("color", "red").appendTo(output);
-            output.get(0).scrollTop = output.get(0).scrollHeight;
+            sendOutputToBottom();
         };
 
 
@@ -32,6 +37,7 @@ $(document).ready(function() {
             // Load up the language.
             M.modules['whalesong/wescheme/lang/semantics.rkt'] =
                 M.installedModules['whalesong/wescheme/lang/semantics.rkt']();
+            
             var semanticsModule =
                 M.modules['whalesong/wescheme/lang/semantics.rkt'];
             semanticsModule.invoke(
@@ -97,6 +103,7 @@ $(document).ready(function() {
             .css("color", "red")
             .appendTo(output);
         $("<br/>").appendTo(output);
+        sendOutputToBottom();
     };