now actually works

ihaskell-display/ihaskell-parsec/widget.js

@@ -7,6 +7,8 @@ if (initialized && window.parsecWidgetRegistered === undefined) {
 // Do not load this script again.
 window.parsecWidgetRegistered = true;
 
+var parsecWidgetCounter = 0;
+
 // Register the comm target.
 var ParsecWidget = function (comm) {
     this.comm = comm;
@@ -47,6 +49,10 @@ var ParsecWidget = function (comm) {
     var out = this.cell.output_area.element;
     this.textarea = out.find("#parsec-editor")[0];
     this.output = out.find("#parsec-output")[0];
+    // Give the elements a different name.
+    this.textarea.id += parsecWidgetCounter;
+    this.output.id += parsecWidgetCounter;
+    parsecWidgetCounter++;
 
     var editor = CodeMirror.fromTextArea(this.textarea, options);
     var editor = editor;
@@ -61,14 +67,13 @@ var ParsecWidget = function (comm) {
 ParsecWidget.prototype.handler = function(msg) {
     var data = msg.content.data;
     this.hasError = data["status"] == "error";
+    console.log('handler', msg);
     if (this.hasError) {
-        out = data["msg"];
+        this.output.innerHTML = data["msg"];
         this.error = data;
     } else {
-        out = data["result"];
+        this.output.innerHTML = data["result"];
     }
-    // Update viewed output.
-    this.output.innerHTML = out;
 };
 
 // Register this widget.

notebooks/Test.ipynb

@@ -3,7 +3,7 @@
   "celltoolbar": "Hiding",
   "language": "haskell",
   "name": "",
-  "signature": "sha256:444705f910fcdf32804f8966333f9306a779ea3b3a6123eff79873d78e4c6f56"
+  "signature": "sha256:804b433cf50ca6157f3f59dbddeffdb20dda07eee3e4701830f71f5eee0fbfd3"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -36,16 +36,22 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "Slider"
+      "1+1"
      ],
      "language": "python",
-     "metadata": {},
+     "metadata": {
+      "hidden": false
+     },
      "outputs": [
       {
        "metadata": {},
-       "output_type": "display_data"
+       "output_type": "display_data",
+       "text": [
+        "2"
+       ]
       }
-     ]
+     ],
+     "prompt_number": 1
     },
     {
      "cell_type": "code",
@@ -104,6 +110,8 @@
         "// Do not load this script again.\n",
         "window.parsecWidgetRegistered = true;\n",
         "\n",
+        "var parsecWidgetCounter = 0;\n",
+        "\n",
         "// Register the comm target.\n",
         "var ParsecWidget = function (comm) {\n",
         "    this.comm = comm;\n",
@@ -144,6 +152,10 @@
         "    var out = this.cell.output_area.element;\n",
         "    this.textarea = out.find(\"#parsec-editor\")[0];\n",
         "    this.output = out.find(\"#parsec-output\")[0];\n",
+        "    // Give the elements a different name.\n",
+        "    this.textarea.id += parsecWidgetCounter;\n",
+        "    this.output.id += parsecWidgetCounter;\n",
+        "    parsecWidgetCounter++;\n",
         "\n",
         "    var editor = CodeMirror.fromTextArea(this.textarea, options);\n",
         "    var editor = editor;\n",
@@ -158,14 +170,13 @@
         "ParsecWidget.prototype.handler = function(msg) {\n",
         "    var data = msg.content.data;\n",
         "    this.hasError = data[\"status\"] == \"error\";\n",
+        "    console.log('handler', msg);\n",
         "    if (this.hasError) {\n",
-        "        out = data[\"msg\"];\n",
+        "        this.output.innerHTML = data[\"msg\"];\n",
         "        this.error = data;\n",
         "    } else {\n",
-        "        out = data[\"result\"];\n",
+        "        this.output.innerHTML = data[\"result\"];\n",
         "    }\n",
-        "    // Update viewed output.\n",
-        "    this.output.innerHTML = out;\n",
         "};\n",
         "\n",
         "// Register this widget.\n",

src/IHaskell/Eval/Lint.hs

@@ -56,14 +56,14 @@ lintIdent = "lintIdentAEjlkQeh"
 lint :: [Located CodeBlock] -> IO Display
 lint blocks = do
   -- Initialize hlint settings
-  initialized <- isEmptyMVar hlintSettings
-  when (not initialized) $ autoSettings >>= putMVar hlintSettings
+  initialized <- not <$> isEmptyMVar hlintSettings
+  when (not initialized) $ do
+    autoSettings >>= putMVar hlintSettings
 
   -- Get hlint settings
   (flags, classify, hint) <- readMVar hlintSettings
   let mode = hseFlags flags
 
-
   -- create 'suggestions'
   let modules = mapMaybe (createModule mode) blocks
       ideas = applyHints classify hint modules