All declarations are now grouped. allows operators more easily.

notebooks/Test.ipynb

@@ -3,7 +3,7 @@
   "celltoolbar": "Hiding",
   "language": "haskell",
   "name": "",
-  "signature": "sha256:b630a2733d4a58680ceb3b868982dc891d570e9ccad5ce31a29d5e1c110962b7"
+  "signature": "sha256:1a476f19eca338ce4e01b81006d0a165e437bdcebbbea6d1ac10e0cd217740ee"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -36,8 +36,15 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      ":ext NoImplicitPrelude\n",
-      "4 + 4"
+      "infixl 3 <<>>\n",
+      "a <<>> 1 = a + 1\n",
+      "a <<>> 3 = a - 1\n",
+      "(<<>>) a b = a * 3\n",
+      "\n",
+      "f :: Int -> Int\n",
+      "f x = x + x\n",
+      "\n",
+      "f 3 <<>> f 3"
      ],
      "language": "python",
      "metadata": {
@@ -45,18 +52,14 @@
      },
      "outputs": [
       {
-       "html": [
-        "<span class='err-msg'>Not in scope: `+'<br/>Perhaps you meant `IHaskellPrelude.+' (imported from Prelude)</span>"
-       ],
        "metadata": {},
        "output_type": "display_data",
        "text": [
-        "Not in scope: `+'\n",
-        "Perhaps you meant `IHaskellPrelude.+' (imported from Prelude)"
+        "18"
        ]
       }
      ],
-     "prompt_number": 3
+     "prompt_number": 2
     },
     {
      "cell_type": "code",
@@ -100,113 +103,28 @@
       "parser"
      ],
      "language": "python",
-     "metadata": {
-      "hidden": false
-     },
+     "metadata": {},
      "outputs": [
-      {
-       "javascript": [
-        "// Only load this script once.\n",
-        "var kernel = IPython.notebook.kernel;\n",
-        "var initialized = kernel !== undefined && kernel != null;\n",
-        "console.log(\"Initialized\", initialized);\n",
-        "if (initialized && window.parsecWidgetRegistered === undefined) {\n",
-        "\n",
-        "// 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",
-        "    this.comm.on_msg($.proxy(this.handler, this));\n",
-        "\n",
-        "    // Get the cell that was probably executed.\n",
-        "    // The msg_id:cell mapping will make this possible without guessing.\n",
-        "    this.cell = IPython.notebook.get_cell(IPython.notebook.get_selected_index()-1);\n",
-        "\n",
-        "    // Store this widget so we can use it from callbacks.\n",
-        "    var widget = this;\n",
-        "\n",
-        "    // Editor options.\n",
-        "    var options = {\n",
-        "        lineNumbers: true,\n",
-        "        // Show parsec errors as lint errors.\n",
-        "        gutters: [\"CodeMirror-lint-markers\"],\n",
-        "        lintWith: {\n",
-        "            \"getAnnotations\": function(cm, update, opts) {\n",
-        "                var errs = [];\n",
-        "                if (widget.hasError) {\n",
-        "                    var col = widget.error[\"col\"];\n",
-        "                    var line = widget.error[\"line\"];\n",
-        "                    errs = [{\n",
-        "                        from: CodeMirror.Pos(line - 1, col - 1),\n",
-        "                        to: CodeMirror.Pos(line - 1, col),\n",
-        "                        message: widget.error[\"msg\"],\n",
-        "                        severity: \"error\"\n",
-        "                    }];\n",
-        "                }\n",
-        "                update(cm, errs);\n",
-        "            },\n",
-        "            \"async\": true,\n",
-        "        }\n",
-        "    };\n",
-        "\n",
-        "    // Create the editor.\n",
-        "    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",
-        "\n",
-        "    // Update every key press.\n",
-        "    editor.on(\"keyup\", function() {\n",
-        "        var text = editor.getDoc().getValue();\n",
-        "        comm.send({\"text\": text});\n",
-        "    });\n",
-        "};\n",
-        "\n",
-        "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",
-        "        this.output.innerHTML = data[\"msg\"];\n",
-        "        this.error = data;\n",
-        "    } else {\n",
-        "        this.output.innerHTML = data[\"result\"];\n",
-        "    }\n",
-        "};\n",
-        "\n",
-        "// Register this widget.\n",
-        "IPython.notebook.kernel.comm_manager.register_target('parsec', IPython.utils.always_new(ParsecWidget));\n",
-        "console.log(\"Registering Parsec widget.\");\n",
-        "}\n"
-       ],
-       "metadata": {},
-       "output_type": "display_data"
-      },
       {
        "html": [
-        "<!-- CodeMirror component -->\n",
-        "<link rel=\"stylesheet\" href=\"/static/components/codemirror/addon/lint/lint.css\">\n",
-        "<script src=\"/static/components/codemirror/addon/lint/lint.js\" charset=\"utf-8\"></script>\n",
-        "\n",
-        "<!-- Parsec widget DOM -->\n",
-        "<form><textarea id=\"parsec-editor\">Insert parser text here...</textarea></form>\n",
-        "<pre id=\"parsec-output\"></pre>\n"
+        "<div class='collapse-group'><span class='btn' href='#' id='unshowable'>Unshowable:<span class='show-type'>Parser List</span></span><span class='err-msg collapse'>No instance for (Show (Parser List)) arising from a use of `print'<br/>Possible fix: add an instance declaration for (Show (Parser List))<br/>In a stmt of an interactive GHCi command: print it</span></div><script>$('#unshowable').on('click', function(e) {\n",
+        "    e.preventDefault();\n",
+        "    var $this = $(this);\n",
+        "    var $collapse = $this.closest('.collapse-group').find('.err-msg');\n",
+        "    $collapse.collapse('toggle');\n",
+        "});\n",
+        "</script>"
        ],
        "metadata": {},
-       "output_type": "display_data"
+       "output_type": "display_data",
+       "text": [
+        "No instance for (Show (Parser List)) arising from a use of `print'\n",
+        "Possible fix: add an instance declaration for (Show (Parser List))\n",
+        "In a stmt of an interactive GHCi command: print it"
+       ]
       }
      ],
-     "prompt_number": 2
+     "prompt_number": 1
     },
     {
      "cell_type": "code",

src/IHaskell/Eval/Parser.hs

@@ -189,46 +189,23 @@ parseCodeChunk code startLine = do
 -- a single declaration. These declarations may also include a type
 -- signature, which is also joined with the subsequent declarations.
 joinFunctions :: [Located CodeBlock] -> [Located CodeBlock]
-joinFunctions (Located line (Declaration decl) : rest) =
-    -- Find all declarations having the same name as this one.
-    let (decls, other) = havingSameName rest in
-      -- Convert them into a single declaration.
-      Located line (Declaration (joinLines $ map (undecl . unloc) decls)) : joinFunctions other
-  where
-    undecl (Declaration decl) = decl
-    undecl _ = error "Expected declaration!"
-
-    -- Get all declarations with the same name as the first declaration.
-    -- The name of a declaration is the first word, which we expect to be
-    -- the name of the function.
-    havingSameName :: [Located CodeBlock] -> ([Located CodeBlock], [Located CodeBlock])
-    havingSameName blocks =
-      let name = head $ words decl
-          sameName = takeWhile (isNamedDecl name) rest
-          others = drop (length sameName) rest in
-        (Located line (Declaration decl) : sameName, others)
-
-    isNamedDecl :: String -> Located CodeBlock -> Bool
-    isNamedDecl name (Located _ (Declaration dec)) = head (words dec) == name
-    isNamedDecl _ _ = False
-
--- Allow a type signature followed by declarations to be joined to the
--- declarations. Parse the declaration joining separately.
-joinFunctions (Located line (TypeSignature sig) : Located dl (Declaration decl) : rest) =
-  Located line (Declaration $ sig ++ "\n" ++ joinedDecl):remaining
-  where Located _ (Declaration joinedDecl):remaining = joinFunctions $ Located dl (Declaration decl) : rest
-
--- Also allow two type signatures. This is necessary for operator
--- declarations in which you have a fixity declaration.
-joinFunctions (Located line (TypeSignature sig) :
-               Located _ (TypeSignature sig')   :
-               Located dl (Declaration decl)    : rest) =
-  Located line (Declaration $ intercalate "\n" [sig, sig', joinedDecl]):remaining
-  where Located _ (Declaration joinedDecl):remaining = joinFunctions $ Located dl (Declaration decl) : rest
-
-joinFunctions (x:xs) = x : joinFunctions xs
 joinFunctions [] = []
+joinFunctions blocks = Located lnum (conjoin $ map unloc decls) : joinFunctions rest
+  where 
+    decls = takeWhile (signatureOrDecl . unloc) blocks
+    rest = drop (length decls) blocks
+    lnum = line $ head decls
 
+    signatureOrDecl (Declaration _) = True
+    signatureOrDecl (TypeSignature _) = True
+    signatureOrDecl _ = False
+
+    str (Declaration s) = s
+    str (TypeSignature s) = s
+    str _ = error "Expected declaration or signature"
+
+    conjoin :: [CodeBlock] -> CodeBlock
+    conjoin = Declaration . intercalate "\n" . map str
 
 -- | Parse a directive of the form :directiveName.
 parseDirective :: String       -- ^ Directive string.