Triage Expect.

dart/frog/leg/ssa/codegen.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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
   String generate(WorkItem work, HGraph graph) {
     return measure(() {
@@ skipping 787 matching lines @@
     } else if (element == coreLibrary.find(const SourceString('bool'))) {
       checkBool(input, '===');
     } else if (element == coreLibrary.find(const SourceString('int'))) {
       checkNum(input, '===');
       buffer.add(' && ');
       checkInt(input, '===');
     } else {
       checkObject(input, '===');
       buffer.add(' && (');
       if (element == coreLibrary.find(const SourceString('List'))) {
+        buffer.add('(');
+        checkObject(input, '===');

[ngeoffray, 2012/02/21 12:23:51]

checkObject is already done line 805.

+        buffer.add(' && ');
         checkArray(input, '===');
-        buffer.add(' || ');
+        buffer.add(') || ');
       }
       buffer.add('!!(');
       use(input);
       buffer.add('.');
       buffer.add(compiler.namer.operatorIs(node.typeExpression));
       buffer.add('))');
     }
     buffer.add(')');
   }
 }
@@ skipping 63 matching lines @@
       checkBool(input, '!==');
       buffer.add(') ');
       bailout(node, 'Not a boolean');
     } else if (node.isString()) {
       buffer.add('if (');
       checkString(input, '!==');
       buffer.add(') ');
       bailout(node, 'Not a string');
     } else if (node.isArray()) {
       buffer.add('if (');
+      checkObject(input, '!==');

[ngeoffray, 2012/02/21 12:23:51]

Please add a comment that this is actually a null check.

+      buffer.add('||');
       checkArray(input, '!==');
       buffer.add(') ');
       bailout(node, 'Not an array');
     } else if (node.isStringOrArray()) {
       buffer.add('if (');
       checkString(input, '!==');
-      buffer.add(' && ');
+      buffer.add(' && (');
+      checkObject(input, '!==');
+      buffer.add('||');
       checkArray(input, '!==');
-      buffer.add(') ');
+      buffer.add(')) ');
       bailout(node, 'Not a string or array');
     } else {
       unreachable();
     }
   }
 
   void beginLoop(HBasicBlock block) {
     addIndentation();
     buffer.add('while (true) {\n');
     indent++;
@@ skipping 244 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endElse(HIf node) {
     if (node.elseBlock.hasBailouts()) {
       endBailoutSwitch();
     }
   }
 }