Emit classes using ASTs

sdk/lib/_internal/compiler/implementation/js/printer.dart

 // Copyright (c) 2012, 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.
 
 part of js;
 
 class Printer implements NodeVisitor {
   final bool shouldCompressOutput;
   leg.Compiler compiler;
   leg.CodeBuffer outBuffer;
@@ skipping 13 matching lines @@
         danglingElseVisitor = new DanglingElseVisitor(compiler),
         localNamer = determineRenamer(compiler.enableMinification,
                                       allowVariableMinification);
 
   static LocalNamer determineRenamer(bool shouldCompressOutput,
                                      bool allowVariableMinification) {
     return (shouldCompressOutput && allowVariableMinification)
         ? new MinifyRenamer() : new IdentityNamer();
   }
 
+  void newLine() {

[floitsch, 2013/01/04 10:31:03]

do we really need this?
If yes, please add comments, so that the editor can provide hover-over
information, explaining the difference between newLine and lineOut.

[sra1, 2013/01/04 23:47:52]

Done.

+    out("\n");
+  }
+
   void spaceOut() {
     if (!shouldCompressOutput) out(" ");
   }
   void lineOut() {
-    if (!shouldCompressOutput) out("\n");
+    if (!shouldCompressOutput) newLine();
   }
 
   String lastAddedString = null;
   int get lastCharCode {
     if (lastAddedString == null) return 0;
     assert(lastAddedString.length != "");
     return lastAddedString.charCodeAt(lastAddedString.length - 1);
   }
 
   void out(String str) {
@@ skipping 14 matching lines @@
 
   void outLn(String str) {
     out(str);
     lineOut();
   }
 
   void outSemicolonLn() {
     if (shouldCompressOutput) {
       pendingSemicolon = true;
     } else {
-      out(";\n");
+      out(";");
+      newLine();
     }
   }
 
   void outIndent(String str) { indent(); out(str); }
   void outIndentLn(String str) { indent(); outLn(str); }
   void indent() {
     if (!shouldCompressOutput) {
       for (int i = 0; i < indentLevel; i++) out("  ");
     }
   }
@@ skipping 581 matching lines @@
       // TODO(floitsch): allow more characters.
       int charCode = field.charCodeAt(i);
       if (!(charCodes.$a <= charCode && charCode <= charCodes.$z ||
             charCodes.$A <= charCode && charCode <= charCodes.$Z ||
             charCode == charCodes.$$ ||
             charCode == charCodes.$_ ||
             i != 1 && isDigit(charCode))) {
         return false;
       }
     }
-    // TODO(floitsch): normally we should also check that the field is not
-    // a reserved word.
+    // TODO(floitsch): normally we should also check that the field is not a
+    // reserved word.  We don't generate fields with reserved word names except
+    // for 'super'.
+    if (field == '"super"') return false;
     return true;
   }
 
   visitAccess(PropertyAccess access) {
     visitNestedExpression(access.receiver, CALL,
                           newInForInit: inForInit,
                           newAtStatementBegin: atStatementBegin);
     Node selector = access.selector;
     if (selector is LiteralString) {
       LiteralString selectorString = selector;
@@ skipping 64 matching lines @@
       }
     }
     out("]");
   }
 
   visitArrayElement(ArrayElement node) {
     throw "Unreachable";
   }
 
   visitObjectInitializer(ObjectInitializer node) {
+    // Print all the properties on one line until we see a function-valued
+    // property.  Ideally, we would use a proper pretty-printer to make the
+    // decision based on layout.
+    bool onePerLine = false;
+    List<Property> properties = node.properties;
     out("{");
-    List<Property> properties = node.properties;
+    ++indentLevel;
     for (int i = 0; i < properties.length; i++) {
+      Expression value = properties[i].value;
+      if (value is Fun || value is NamedFunction) onePerLine = true;
       if (i != 0) {
         out(",");
-        spaceOut();
+        if (!onePerLine) spaceOut();
+      }
+      if (onePerLine) {
+        newLine();

[floitsch, 2013/01/04 10:31:03]

why "newLine" and not "lineOut" ?

[sra1, 2013/01/04 23:47:52]

To force newlines even under --minify.
We can play with this, but it matches current behaviour.
Otherwise the code is completely unreadable when minified.

[floitsch, 2013/01/04 23:58:20]

Fine with me, but I wouldn't consider readability a necessary feature for
minified code.

+        indent();
       }
       visitProperty(properties[i]);
     }
+    --indentLevel;
+    if (onePerLine) lineOut();
     out("}");
   }
 
   visitProperty(Property node) {
     if (node.name is LiteralString) {
       LiteralString nameString = node.name;
       String name = nameString.value;
       if (isValidJavaScriptId(name)) {
         out(name.substring(1, name.length - 1));
       } else {
@@ skipping 285 matching lines @@
         codes.add(nthLetter((n ~/ nameSpaceSize) % LETTERS));
       }
       codes.add(charCodes.$0 + digit);
       newName = new String.fromCharCodes(codes);
     }
     assert(new RegExp(r'[a-zA-Z][a-zA-Z0-9]*').hasMatch(newName));
     maps.last[oldName] = newName;
     return newName;
   }
 }