Improve double implementation.

dart/frog/leg/compile_time_constants.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.
 
 // TODO(floitsch): finish implementation.
 class CompileTimeConstant implements Hashable {
   static int idCounter = 0;
 
   // TODO(floitsch): don't just expose the name.
   final String name;
@@ skipping 143 matching lines @@
   }
 
   List<CompileTimeConstant> getCompileTimeConstantsForEmission() {
     return new List<CompileTimeConstant>.from(compiledConstants);
   }
 
   StringBuffer writeJsCode(StringBuffer buffer, var value) {
     if (value === null) {
       buffer.add("(void 0)");
     } else if (value is num) {
-      if (value.isNaN()) buffer.add("(0/0)");
-      if (value == double.INFINITY) buffer.add("(1/0)");
-      if (value == -double.INFINITY) buffer.add("(-1/0)");
-      buffer.add("($value)");
+      if (value.isNaN()) {
+        buffer.add("(0/0)");
+      } else if (value == double.INFINITY) {
+        buffer.add("(1/0)");
+      } else if (value == -double.INFINITY) {
+        buffer.add("(-1/0)");
+      } else {
+        buffer.add("($value)");
+      }
     } else if (value === true) {
       buffer.add("true");
     } else if (value === false) {
       buffer.add("false");
     } else if (value is DartString) {
       buffer.add("'");
       writeEscapedString(value, buffer, (reason) {
         compiler.cancel("failed to write escaped string: $value");
       });
       buffer.add("'");
@@ skipping 219 matching lines @@
     return constantHandler.compileListLiteral(node, arguments);
   }
 
   error(Node node) {
     // TODO(floitsch): get the list of constants that are currently compiled
     // and present some kind of stack-trace.
     MessageKind kind = MessageKind.NOT_A_COMPILE_TIME_CONSTANT;
     compiler.reportError(node, new CompileTimeConstantError(kind, const []));
   }
 }