Fix a spurious warning in Frog selfhost

frog/frogsh

 #!/usr/bin/env node
 //  ********** Library dart:core **************
 //  ********** Natives dart:core **************
 /**
  * Generates a dynamic call stub for a function.
  * Our goal is to create a stub method like this on-the-fly:
  *   function($0, $1, capture) { this($0, $1, true, capture); }
  *
  * This stub then replaces the dynamic one on Function, with one that is
  * specialized for that particular function, taking into account its default
@@ skipping 91 matching lines @@
       res = new StackOverflowException();
     }
   }
   // TODO(jmesserly): setting the stack property is not a long term solution.
   // Also it causes the exception to print as if it were a TypeError or
   // RangeError, instead of using the proper toString.
   res.stack = e.stack;
   return res;
 }
 function $notnull_bool(test) {
-  return (test === true || test === false) ? test : test.is$bool();
+  return (test === true || test === false) ? test : test.is$bool(); // TypeError
 }
 function $assert(test, text, url, line, column) {
   if (typeof test == 'function') test = test();
   if (!test) $throw(new AssertError(text, url, line, column));
 }
 function $throw(e) {
   // If e is not a value, we can use V8's captureStackTrace utility method.
   // TODO(jmesserly): capture the stack trace on other JS engines.
   if (e && (typeof e == 'object') && Error.captureStackTrace) {
     // TODO(jmesserly): this will clobber the e.stack property
     Error.captureStackTrace(e, $throw);
   }
   throw e;
 }
 function $map(items) {
   var ret = new HashMapImplementation();
   for (var i=0; i < items.length;) {
     ret.$setindex(items[i++], items[i++]);
   }
   return ret;
 }
 Object.prototype.$index = function(i) { return this[i]; }
 Array.prototype.$index = function(i) { return this[i]; }
 String.prototype.$index = function(i) { return this[i]; }
 Object.prototype.$setindex = function(i, value) { return this[i] = value; }
 Array.prototype.$setindex = function(i, value) { return this[i] = value; }
+function $add(x, y) {
+  return ((typeof(x) == 'number' && typeof(y) == 'number') ||
+          (typeof(x) == 'string' && typeof(y) == 'string'))
+    ? x + y : x.$add(y);
+}
 function $eq(x, y) {
   if (x == null) return y == null;
   return (typeof(x) == 'number' && typeof(y) == 'number') ||
          (typeof(x) == 'boolean' && typeof(y) == 'boolean') ||
          (typeof(x) == 'string' && typeof(y) == 'string')
     ? x == y : x.$eq(y);
 }
 // TODO(jimhug): Should this or should it not match equals?
 Object.prototype.$eq = function(other) { return this === other; }
 function $mod(x, y) {
@@ skipping 75 matching lines @@
 };
 Object.prototype.addDirectSubtype$1 = function($0) {
   return this.noSuchMethod("addDirectSubtype", [$0]);
 };
 Object.prototype.addMethod$2 = function($0, $1) {
   return this.noSuchMethod("addMethod", [$0, $1]);
 };
 Object.prototype.addSource$1 = function($0) {
   return this.noSuchMethod("addSource", [$0]);
 };
+Object.prototype.appendByteStringToken$2 = function($0, $1) {
+  return this.noSuchMethod("appendByteStringToken", [$0, $1]);
+};
 Object.prototype.beginArguments$1 = function($0) {
   return this.noSuchMethod("beginArguments", [$0]);
 };
 Object.prototype.beginBlock$1 = function($0) {
   return this.noSuchMethod("beginBlock", [$0]);
 };
 Object.prototype.beginClass$1 = function($0) {
   return this.noSuchMethod("beginClass", [$0]);
 };
 Object.prototype.beginExpressionStatement$1 = function($0) {
@@ skipping 2134 matching lines @@
 }
 Object.defineProperty(DoubleLinkedQueue.prototype, "length", {
   get: DoubleLinkedQueue.prototype.get$length
 });
 DoubleLinkedQueue.prototype.isEmpty = function() {
   return (this._sentinel._next === this._sentinel);
 }
 DoubleLinkedQueue.prototype.forEach = function(f) {
   var entry = this._sentinel._next;
   while (entry !== this._sentinel) {
+    var nextEntry = entry._next;
     f(entry._element);
-    entry = entry._next;
+    entry = nextEntry;
   }
 }
 DoubleLinkedQueue.prototype.some = function(f) {
   var entry = this._sentinel._next;
   while (entry !== this._sentinel) {
+    var nextEntry = entry._next;
     if (f(entry._element)) return true;
-    entry = entry._next;
+    entry = nextEntry;
   }
   return false;
 }
 DoubleLinkedQueue.prototype.filter = function(f) {
   var other = new DoubleLinkedQueue();
   var entry = this._sentinel._next;
   while (entry !== this._sentinel) {
+    var nextEntry = entry._next;
     if (f(entry._element)) other.addLast(entry._element);
-    entry = entry._next;
+    entry = nextEntry;
   }
   return other;
 }
 DoubleLinkedQueue.prototype.iterator = function() {
   return new _DoubleLinkedQueueIterator$E(this._sentinel);
 }
 DoubleLinkedQueue.prototype.add$1 = DoubleLinkedQueue.prototype.add;
 DoubleLinkedQueue.prototype.addAll$1 = function($0) {
   return this.addAll(($0 && $0.is$Collection$E()));
 };
@@ skipping 37 matching lines @@
 DoubleLinkedQueue$KeyValuePair$K$V.prototype.is$Iterable = function(){return this;};
 DoubleLinkedQueue$KeyValuePair$K$V.prototype.addLast = function(value) {
   this._sentinel.prepend(value);
 }
 DoubleLinkedQueue$KeyValuePair$K$V.prototype.lastEntry = function() {
   return this._sentinel.previousEntry();
 }
 DoubleLinkedQueue$KeyValuePair$K$V.prototype.forEach = function(f) {
   var entry = this._sentinel._next;
   while (entry !== this._sentinel) {
+    var nextEntry = entry._next;
     f(entry._element);
-    entry = entry._next;
+    entry = nextEntry;
   }
 }
 // ********** Code for DoubleLinkedQueue$SourceString **************
 function DoubleLinkedQueue$SourceString() {}
 $inherits(DoubleLinkedQueue$SourceString, DoubleLinkedQueue);
 DoubleLinkedQueue$SourceString.prototype.is$Collection$E = function(){return this;};
 DoubleLinkedQueue$SourceString.prototype.is$Collection$Object = function(){return this;};
 DoubleLinkedQueue$SourceString.prototype.is$Collection$Type = false;
 DoubleLinkedQueue$SourceString.prototype.is$Iterable = function(){return this;};
 // ********** Code for _DoubleLinkedQueueIterator **************
@@ skipping 254 matching lines @@
 }
 DateImplementation.now$ctor.prototype = DateImplementation.prototype;
 DateImplementation.prototype.is$Date = function(){return this;};
 DateImplementation.prototype.is$Comparable = function(){return this;};
 DateImplementation.prototype.get$value = function() { return this.value; };
 DateImplementation.prototype.$eq = function(other) {
   if (!((other instanceof DateImplementation))) return false;
   return (this.value == other.get$value()) && ($eq(this.timeZone, other.timeZone));
 }
 DateImplementation.prototype.compareTo = function(other) {
-  return this.value.compareTo(other.value);
+  var $0;
+  return $assert_num(this.value.compareTo$1(other.value));
 }
 DateImplementation.prototype.get$year = function() {
   return this.isUtc ? this._asJs().getUTCFullYear() :
       this._asJs().getFullYear();
 }
 DateImplementation.prototype.get$month = function() {
   return this.isUtc ? this._asJs().getMonth() + 1 :
         this._asJs().getMonth() + 1;
 }
 DateImplementation.prototype.get$day = function() {
@@ skipping 1810 matching lines @@
       return this.select(61/*null.$EQ*/, "<<=", "<<");
 
     default:
 
       this.appendBeginGroup(60/*null.LT_TOKEN*/, "<");
       return next;
 
   }
 }
 AbstractScanner.prototype.tokenizeNumber = function(next) {
+  var $0;
   var start = this.get$byteOffset();
   while (true) {
     next = this.advance();
     switch (next) {
       case 48/*null.$0*/:
       case 49/*null.$1*/:
       case 50/*null.$2*/:
       case 51/*null.$3*/:
       case 52/*null.$4*/:
       case 53/*null.$5*/:
@@ skipping 10 matching lines @@
 
       case 101/*null.$e*/:
       case 69/*null.$E*/:
       case 100/*null.$d*/:
       case 68/*null.$D*/:
 
         return this.tokenizeFractionPart(next, start);
 
       default:
 
-        this.appendByteStringToken(105/*null.INT_TOKEN*/, this.asciiString(start));
+        this.appendByteStringToken$2(105/*null.INT_TOKEN*/, this.asciiString(start));
         return next;
 
     }
   }
 }
 AbstractScanner.prototype.tokenizeHexOrNumber = function(next) {
   var x = this.peek();
   if (x == 120/*null.$x*/ || x == 88/*null.$X*/) {
     this.advance();
     return this.tokenizeHex(x);
   }
   return this.tokenizeNumber(next);
 }
 AbstractScanner.prototype.tokenizeHex = function(next) {
+  var $0;
   var start = this.get$byteOffset();
   var hasDigits = false;
   while (true) {
     next = this.advance();
     switch (next) {
       case 48/*null.$0*/:
       case 49/*null.$1*/:
       case 50/*null.$2*/:
       case 51/*null.$3*/:
       case 52/*null.$4*/:
@@ skipping 16 matching lines @@
       case 102/*null.$f*/:
 
         hasDigits = true;
         break;
 
       default:
 
         if (!$notnull_bool(hasDigits)) {
           $throw(new MalformedInputException(this.get$charOffset()));
         }
-        this.appendByteStringToken(120/*null.HEXADECIMAL_TOKEN*/, this.asciiString(start));
+        this.appendByteStringToken$2(120/*null.HEXADECIMAL_TOKEN*/, this.asciiString(start));
         return next;
 
     }
   }
 }
 AbstractScanner.prototype.tokenizeDotOrNumber = function(next) {
   var start = this.get$byteOffset();
   next = this.advance();
   switch (next) {
     case 48/*null.$0*/:
@@ skipping 16 matching lines @@
       return this.select(46/*null.$PERIOD*/, "...", "..");
 
     default:
 
       this.appendStringToken(46/*null.PERIOD_TOKEN*/, ".");
       return next;
 
   }
 }
 AbstractScanner.prototype.tokenizeFractionPart = function(next, start) {
+  var $0;
   var done = false;
   LOOP:
   while (!$notnull_bool(done)) {
     switch (next) {
       case 48/*null.$0*/:
       case 49/*null.$1*/:
       case 50/*null.$2*/:
       case 51/*null.$3*/:
       case 52/*null.$4*/:
       case 53/*null.$5*/:
@@ skipping 15 matching lines @@
 
         done = true;
         continue LOOP;
 
     }
     next = this.advance();
   }
   if (next == 100/*null.$d*/ || next == 68/*null.$D*/) {
     next = this.advance();
   }
-  this.appendByteStringToken(100/*null.DOUBLE_TOKEN*/, this.asciiString(start));
+  this.appendByteStringToken$2(100/*null.DOUBLE_TOKEN*/, this.asciiString(start));
   return next;
 }
 AbstractScanner.prototype.tokenizeExponent = function(next) {
   if (next == 43/*null.$PLUS*/ || next == 45/*null.$MINUS*/) {
     next = this.advance();
   }
   var hasDigits = false;
   while (true) {
     switch (next) {
       case 48/*null.$0*/:
@@ skipping 78 matching lines @@
 
       default:
 
         next = this.advance();
         break;
 
     }
   }
 }
 AbstractScanner.prototype.tokenizeIdentifier = function(next) {
+  var $0;
   var start = this.get$byteOffset();
   var state = null;
   if (97/*null.$a*/ <= next && next <= 122/*null.$z*/) {
     state = KeywordState.get$KEYWORD_STATE().next(next);
     next = this.advance();
   }
   var isAscii = true;
   while (true) {
     if (97/*null.$a*/ <= next && next <= 122/*null.$z*/) {
       if (state != null) {
         state = state.next(next);
       }
     }
     else if ((48/*null.$0*/ <= next && next <= 57/*null.$9*/) || (65/*null.$A*/ <= next && next <= 90/*null.$Z*/) || next == 95/*null.$_*/ || next == 36/*null.$DOLLAR*/) {
       state = null;
     }
     else if (next < 128) {
       if ($notnull_bool(state != null && state.isLeaf())) {
         this.appendKeywordToken(state.get$keyword());
       }
       else if ($notnull_bool(isAscii)) {
-        this.appendByteStringToken(97/*null.IDENTIFIER_TOKEN*/, this.asciiString(start));
+        this.appendByteStringToken$2(97/*null.IDENTIFIER_TOKEN*/, this.asciiString(start));
       }
       else {
-        this.appendByteStringToken(97/*null.IDENTIFIER_TOKEN*/, this.utf8String(start, -1));
+        this.appendByteStringToken$2(97/*null.IDENTIFIER_TOKEN*/, this.utf8String(start, -1));
       }
       return next;
     }
     else {
       var nonAsciiStart = this.get$byteOffset();
       do {
         next = this.nextByte();
       }
       while (next > 127)
       var string = this.utf8String(nonAsciiStart, -1).toString$0();
       isAscii = false;
       this.addToCharOffset(string.length);
       return next;
     }
     next = this.advance();
   }
 }
 AbstractScanner.prototype.tokenizeRawString = function(next) {
   var start = this.get$byteOffset();
   next = this.advance();
   if (next == 34/*null.$DQ*/ || next == 39/*null.$SQ*/) {
     return this.tokenizeString(next, start, true);
   }
   else {
     $throw(new MalformedInputException(this.get$charOffset()));
   }
 }
 AbstractScanner.prototype.tokenizeString = function(next, start, raw) {
+  var $0;
   var q = next;
   next = this.advance();
   if (q == next) {
     next = this.advance();
     if (q == next) {
       return this.tokenizeMultiLineString(q, start, raw);
     }
     else {
-      this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, -1));
+      this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, -1));
       return next;
     }
   }
   if ($notnull_bool(raw)) {
     return this.tokenizeSingleLineRawString(next, q, start);
   }
   else {
     return this.tokenizeSingleLineString(next, q, start);
   }
 }
 AbstractScanner.prototype.tokenizeSingleLineString = function(next, q1, start) {
+  var $0;
   while (next != -1) {
     if (next == q1) {
-      this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
+      this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
       return this.advance();
     }
     else if (next == 92/*null.$BACKSLASH*/) {
       next = this.advance();
       if (next == -1) {
         $throw(new MalformedInputException(this.get$charOffset()));
       }
     }
     else if (next == 10/*null.$LF*/ || next == 13/*null.$CR*/) {
       $throw(new MalformedInputException(this.get$charOffset()));
     }
     next = this.advance();
   }
   $throw(new MalformedInputException(this.get$charOffset()));
 }
 AbstractScanner.prototype.tokenizeSingleLineRawString = function(next, q1, start) {
+  var $0;
   next = this.advance();
   while (next != -1) {
     if (next == q1) {
-      this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
+      this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
       return this.advance();
     }
     else if (next == 10/*null.$LF*/ || next == 13/*null.$CR*/) {
       $throw(new MalformedInputException(this.get$charOffset()));
     }
     next = this.advance();
   }
   $throw(new MalformedInputException(this.get$charOffset()));
 }
 AbstractScanner.prototype.tokenizeMultiLineString = function(q, start, raw) {
+  var $0;
   var next = this.advance();
   while (next != -1) {
     if (next == q) {
       next = this.advance();
       if (next == q) {
         next = this.advance();
         if (next == q) {
-          this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
+          this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
           return this.advance();
         }
       }
     }
     next = this.advance();
   }
   return next;
 }
+AbstractScanner.prototype.appendByteStringToken$2 = AbstractScanner.prototype.appendByteStringToken;
 // ********** Code for AbstractScanner$S **************
 function AbstractScanner$S() {}
 $inherits(AbstractScanner$S, AbstractScanner);
 AbstractScanner$S.prototype.tokenize = function() {
   var next = this.advance();
   while (next != -1) {
     next = this.bigSwitch(next);
   }
   this.appendEofToken();
   return this.firstToken();
@@ skipping 419 matching lines @@
       return this.select(61/*null.$EQ*/, "<<=", "<<");
 
     default:
 
       this.appendBeginGroup(60/*null.LT_TOKEN*/, "<");
       return next;
 
   }
 }
 AbstractScanner$S.prototype.tokenizeNumber = function(next) {
+  var $0;
   var start = this.get$byteOffset();
   while (true) {
     next = this.advance();
     switch (next) {
       case 48/*null.$0*/:
       case 49/*null.$1*/:
       case 50/*null.$2*/:
       case 51/*null.$3*/:
       case 52/*null.$4*/:
       case 53/*null.$5*/:
@@ skipping 10 matching lines @@
 
       case 101/*null.$e*/:
       case 69/*null.$E*/:
       case 100/*null.$d*/:
       case 68/*null.$D*/:
 
         return this.tokenizeFractionPart(next, start);
 
       default:
 
-        this.appendByteStringToken(105/*null.INT_TOKEN*/, this.asciiString(start));
+        this.appendByteStringToken$2(105/*null.INT_TOKEN*/, this.asciiString(start));
         return next;
 
     }
   }
 }
 AbstractScanner$S.prototype.tokenizeHexOrNumber = function(next) {
   var x = this.peek();
   if (x == 120/*null.$x*/ || x == 88/*null.$X*/) {
     this.advance();
     return this.tokenizeHex(x);
   }
   return this.tokenizeNumber(next);
 }
 AbstractScanner$S.prototype.tokenizeHex = function(next) {
+  var $0;
   var start = this.get$byteOffset();
   var hasDigits = false;
   while (true) {
     next = this.advance();
     switch (next) {
       case 48/*null.$0*/:
       case 49/*null.$1*/:
       case 50/*null.$2*/:
       case 51/*null.$3*/:
       case 52/*null.$4*/:
@@ skipping 16 matching lines @@
       case 102/*null.$f*/:
 
         hasDigits = true;
         break;
 
       default:
 
         if (!$notnull_bool(hasDigits)) {
           $throw(new MalformedInputException(this.get$charOffset()));
         }
-        this.appendByteStringToken(120/*null.HEXADECIMAL_TOKEN*/, this.asciiString(start));
+        this.appendByteStringToken$2(120/*null.HEXADECIMAL_TOKEN*/, this.asciiString(start));
         return next;
 
     }
   }
 }
 AbstractScanner$S.prototype.tokenizeDotOrNumber = function(next) {
   var start = this.get$byteOffset();
   next = this.advance();
   switch (next) {
     case 48/*null.$0*/:
@@ skipping 16 matching lines @@
       return this.select(46/*null.$PERIOD*/, "...", "..");
 
     default:
 
       this.appendStringToken(46/*null.PERIOD_TOKEN*/, ".");
       return next;
 
   }
 }
 AbstractScanner$S.prototype.tokenizeFractionPart = function(next, start) {
+  var $0;
   var done = false;
   LOOP:
   while (!$notnull_bool(done)) {
     switch (next) {
       case 48/*null.$0*/:
       case 49/*null.$1*/:
       case 50/*null.$2*/:
       case 51/*null.$3*/:
       case 52/*null.$4*/:
       case 53/*null.$5*/:
@@ skipping 15 matching lines @@
 
         done = true;
         continue LOOP;
 
     }
     next = this.advance();
   }
   if (next == 100/*null.$d*/ || next == 68/*null.$D*/) {
     next = this.advance();
   }
-  this.appendByteStringToken(100/*null.DOUBLE_TOKEN*/, this.asciiString(start));
+  this.appendByteStringToken$2(100/*null.DOUBLE_TOKEN*/, this.asciiString(start));
   return next;
 }
 AbstractScanner$S.prototype.tokenizeExponent = function(next) {
   if (next == 43/*null.$PLUS*/ || next == 45/*null.$MINUS*/) {
     next = this.advance();
   }
   var hasDigits = false;
   while (true) {
     switch (next) {
       case 48/*null.$0*/:
@@ skipping 78 matching lines @@
 
       default:
 
         next = this.advance();
         break;
 
     }
   }
 }
 AbstractScanner$S.prototype.tokenizeIdentifier = function(next) {
+  var $0;
   var start = this.get$byteOffset();
   var state = null;
   if (97/*null.$a*/ <= next && next <= 122/*null.$z*/) {
     state = KeywordState.get$KEYWORD_STATE().next(next);
     next = this.advance();
   }
   var isAscii = true;
   while (true) {
     if (97/*null.$a*/ <= next && next <= 122/*null.$z*/) {
       if (state != null) {
         state = state.next(next);
       }
     }
     else if ((48/*null.$0*/ <= next && next <= 57/*null.$9*/) || (65/*null.$A*/ <= next && next <= 90/*null.$Z*/) || next == 95/*null.$_*/ || next == 36/*null.$DOLLAR*/) {
       state = null;
     }
     else if (next < 128) {
       if ($notnull_bool(state != null && state.isLeaf())) {
         this.appendKeywordToken(state.get$keyword());
       }
       else if ($notnull_bool(isAscii)) {
-        this.appendByteStringToken(97/*null.IDENTIFIER_TOKEN*/, this.asciiString(start));
+        this.appendByteStringToken$2(97/*null.IDENTIFIER_TOKEN*/, this.asciiString(start));
       }
       else {
-        this.appendByteStringToken(97/*null.IDENTIFIER_TOKEN*/, this.utf8String(start, -1));
+        this.appendByteStringToken$2(97/*null.IDENTIFIER_TOKEN*/, this.utf8String(start, -1));
       }
       return next;
     }
     else {
       var nonAsciiStart = this.get$byteOffset();
       do {
         next = this.nextByte();
       }
       while (next > 127)
       var string = this.utf8String(nonAsciiStart, -1).toString$0();
       isAscii = false;
       this.addToCharOffset(string.length);
       return next;
     }
     next = this.advance();
   }
 }
 AbstractScanner$S.prototype.tokenizeRawString = function(next) {
   var start = this.get$byteOffset();
   next = this.advance();
   if (next == 34/*null.$DQ*/ || next == 39/*null.$SQ*/) {
     return this.tokenizeString(next, start, true);
   }
   else {
     $throw(new MalformedInputException(this.get$charOffset()));
   }
 }
 AbstractScanner$S.prototype.tokenizeString = function(next, start, raw) {
+  var $0;
   var q = next;
   next = this.advance();
   if (q == next) {
     next = this.advance();
     if (q == next) {
       return this.tokenizeMultiLineString(q, start, raw);
     }
     else {
-      this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, -1));
+      this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, -1));
       return next;
     }
   }
   if ($notnull_bool(raw)) {
     return this.tokenizeSingleLineRawString(next, q, start);
   }
   else {
     return this.tokenizeSingleLineString(next, q, start);
   }
 }
 AbstractScanner$S.prototype.tokenizeSingleLineString = function(next, q1, start) {
+  var $0;
   while (next != -1) {
     if (next == q1) {
-      this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
+      this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
       return this.advance();
     }
     else if (next == 92/*null.$BACKSLASH*/) {
       next = this.advance();
       if (next == -1) {
         $throw(new MalformedInputException(this.get$charOffset()));
       }
     }
     else if (next == 10/*null.$LF*/ || next == 13/*null.$CR*/) {
       $throw(new MalformedInputException(this.get$charOffset()));
     }
     next = this.advance();
   }
   $throw(new MalformedInputException(this.get$charOffset()));
 }
 AbstractScanner$S.prototype.tokenizeSingleLineRawString = function(next, q1, start) {
+  var $0;
   next = this.advance();
   while (next != -1) {
     if (next == q1) {
-      this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
+      this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
       return this.advance();
     }
     else if (next == 10/*null.$LF*/ || next == 13/*null.$CR*/) {
       $throw(new MalformedInputException(this.get$charOffset()));
     }
     next = this.advance();
   }
   $throw(new MalformedInputException(this.get$charOffset()));
 }
 AbstractScanner$S.prototype.tokenizeMultiLineString = function(q, start, raw) {
+  var $0;
   var next = this.advance();
   while (next != -1) {
     if (next == q) {
       next = this.advance();
       if (next == q) {
         next = this.advance();
         if (next == q) {
-          this.appendByteStringToken(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
+          this.appendByteStringToken$2(39/*null.STRING_TOKEN*/, this.utf8String(start, 0));
           return this.advance();
         }
       }
     }
     next = this.advance();
   }
   return next;
 }
 // ********** Code for MalformedInputException **************
 function MalformedInputException(message) {
@@ skipping 1843 matching lines @@
   // Initializers done
 }
 $inherits(StringScanner, ArrayBasedScanner$SourceString);
 StringScanner.prototype.nextByte = function() {
   return this.charAt(++this.byteOffset);
 }
 StringScanner.prototype.peek = function() {
   return this.charAt(this.byteOffset + 1);
 }
 StringScanner.prototype.charAt = function(index) {
-  return (this.string.length > $assert_num(index)) ? this.string.charCodeAt(index) : -1;
+  return (this.string.length > $assert_num(index)) ? this.string.charCodeAt($assert_num(index)) : -1;
 }
 StringScanner.prototype.asciiString = function(start) {
   return new SubstringWrapper(this.string, start, this.byteOffset);
 }
 StringScanner.prototype.utf8String = function(start, offset) {
   return new SubstringWrapper(this.string, start, this.byteOffset + offset + 1);
 }
 StringScanner.prototype.appendByteStringToken = function(kind, value) {
   this.tail.next = new StringToken.fromSource$ctor(kind, value, this.tokenStart);
   this.tail = this.tail.next;
 }
+StringScanner.prototype.appendByteStringToken$2 = function($0, $1) {
+  return this.appendByteStringToken($assert_num($0), ($1 && $1.is$SourceString()));
+};
 // ********** Code for SubstringWrapper **************
 function SubstringWrapper(internalString, begin, end) {
   this.internalString = internalString;
   this.begin = begin;
   this.end = end;
   // Initializers done
 }
 SubstringWrapper.prototype.is$SourceString = function(){return this;};
 SubstringWrapper.prototype.hashCode = function() {
   return this.toString().hashCode();
@@ skipping 869 matching lines @@
 // ********** Code for VariableDefinitions **************
 function VariableDefinitions(type, modifiers, definitions, endToken) {
   this.type = type;
   this.modifiers = modifiers;
   this.definitions = definitions;
   this.endToken = endToken;
   // Initializers done
 }
 $inherits(VariableDefinitions, Statement);
 VariableDefinitions.prototype.is$VariableDefinitions = function(){return this;};
+VariableDefinitions.prototype.get$type = function() { return this.type; };
 VariableDefinitions.prototype.accept = function(visitor) {
   return visitor.visitVariableDefinitions(this);
 }
 VariableDefinitions.prototype.getBeginToken = function() {
   return firstBeginToken(this.type, this.definitions);
 }
 VariableDefinitions.prototype.getEndToken = function() {
   return this.endToken;
 }
 VariableDefinitions.prototype.accept$1 = function($0) {
@@ skipping 181 matching lines @@
   return this.hashCode();
 };
 // ********** Code for VariableElement **************
 function VariableElement(node, typeAnnotation, name, enclosingElement) {
   this.node = node;
   this.typeAnnotation = typeAnnotation;
   Element.call(this, name, const$260, enclosingElement);
   // Initializers done
 }
 $inherits(VariableElement, Element);
+VariableElement.prototype.get$type = function() { return this.type; };
+VariableElement.prototype.set$type = function(value) { return this.type = value; };
 VariableElement.prototype.parseNode = function(canceler, logger) {
   return this.node;
 }
 VariableElement.prototype.computeType = function(compiler, types) {
   return getType(this.typeAnnotation, types);
 }
 VariableElement.prototype.computeType$2 = function($0, $1) {
   return this.computeType(($0 && $0.is$Compiler()), ($1 && $1.is$Types()));
 };
 // ********** Code for ForeignElement **************
 function ForeignElement(name) {
   Element.call(this, name, const$242, null);
   // Initializers done
 }
 $inherits(ForeignElement, Element);
 ForeignElement.prototype.computeType = function(compiler, types) {
   return types.dynamicType;
 }
 ForeignElement.prototype.computeType$2 = function($0, $1) {
   return this.computeType(($0 && $0.is$Compiler()), ($1 && $1.is$Types()));
 };
 // ********** Code for FunctionElement **************
 function FunctionElement(name) {
   Element.call(this, name, const$239, null);
   // Initializers done
 }
 $inherits(FunctionElement, Element);
+FunctionElement.prototype.get$type = function() { return this.type; };
+FunctionElement.prototype.set$type = function(value) { return this.type = value; };
 FunctionElement.prototype.computeType = function(compiler, types) {
   var $0;
   if (this.type != null) return (($0 = this.type) && $0.is$FunctionType());
   var node = (($0 = this.parseNode(compiler, compiler)) && $0.is$FunctionExpression());
   var returnType = getType(node.returnType, types);
   if (returnType == null) compiler.cancel(('unknown type ' + returnType + ''));
   var parameterTypes = new LinkBuilderImplementation();
   for (var link = node.parameters.nodes;
    !$notnull_bool(link.isEmpty$0()); link = link.get$tail()) {
     var parameter = (($0 = link.get$head()) && $0.is$VariableDefinitions());
     parameterTypes.addLast(getType(parameter.type, types));
   }
   this.type = new FunctionType(returnType, (($0 = parameterTypes.toLink()) && $0.is$Link$Type()));
   return (($0 = this.type) && $0.is$FunctionType());
 }
 FunctionElement.prototype.computeType$2 = FunctionElement.prototype.computeType;
 // ********** Code for ClassElement **************
 function ClassElement(name) {
   this.interfaces = const$14/*const EmptyLink()*/
   this.isResolved = false
   Element.call(this, name, const$237, null);
   // Initializers done
 }
 $inherits(ClassElement, Element);
 ClassElement.prototype.is$ClassElement = function(){return this;};
+ClassElement.prototype.get$type = function() { return this.type; };
+ClassElement.prototype.set$type = function(value) { return this.type = value; };
 ClassElement.prototype.get$interfaces = function() { return this.interfaces; };
 ClassElement.prototype.set$interfaces = function(value) { return this.interfaces = value; };
 ClassElement.prototype.computeType = function(compiler, types) {
   if (this.type == null) {
     this.type = new SimpleType(this.name, this);
   }
   return this.type;
 }
 ClassElement.prototype.resolve = function(compiler) {
   if ($notnull_bool(this.isResolved)) return;
@@ skipping 1592 matching lines @@
   return node;
 }
 SsaConstantFolder.prototype.visitArithmetic = function(node) {
   var $0;
   var inputs = node.inputs;
   $assert(inputs.length == 2, "inputs.length == 2", "optimize.dart", 57, 12);
   if ($notnull_bool(inputs.$index(0).isLiteralNumber$0() && inputs.$index(1).isLiteralNumber$0())) {
     var op1 = (($0 = inputs.$index(0)) && $0.is$HLiteral());
     var op2 = (($0 = inputs.$index(1)) && $0.is$HLiteral());
     try {
-      var folded = node.evaluate(op1.value, op2.value);
+      var folded = node.evaluate($assert_num(op1.value), $assert_num(op2.value));
       return new HLiteral(folded);
     } catch (e) {
       e = $toDartException(e);
       if (!(e instanceof IntegerDivisionByZeroException)) throw e;
       return node;
     }
   }
   return node;
 }
 SsaConstantFolder.prototype.visitAdd = function(node) {
@@ skipping 394 matching lines @@
   }
   function hasCorrectUses(instruction) {
     if (!$notnull_bool(instruction.isInBasicBlock$0())) return true;
     return HValidator.everyInstruction(instruction.get$usedBy(), (function (use, count) {
       return HValidator.countInstruction(use.inputs, (instruction && instruction.is$HInstruction())) == count;
     })
     );
   }
   this.isValid = $notnull_bool($notnull_bool(this.isValid && hasCorrectInputs(instruction)) && hasCorrectUses(instruction));
 }
-// ********** Code for ValueSetNode **************
-function ValueSetNode() {}
-ValueSetNode.prototype.get$value = function() { return this.value; };
-ValueSetNode.prototype.next$0 = function() {
-  return this.next();
-};
 // ********** Code for top level **************
 //  ********** Library leg **************
 // ********** Code for WorldCompiler **************
 function WorldCompiler(world, script) {
   this.world = world;
   Compiler.call(this, script);
   // Initializers done
 }
 $inherits(WorldCompiler, Compiler);
 WorldCompiler.prototype.log = function(message) {
@@ skipping 641 matching lines @@
 }
 TypeCheckerVisitor.prototype.typeWithDefault = function(node, defaultValue) {
   return node != null ? this.type(node) : defaultValue;
 }
 TypeCheckerVisitor.prototype.type = function(node) {
   var $0;
   if (node == null) this.fail(null, 'unexpected node: null');
   var result = (($0 = node.accept(this)) && $0.is$Type());
   return result;
 }
+TypeCheckerVisitor.prototype.get$type = function() {
+  return TypeCheckerVisitor.prototype.type.bind(this);
+}
 TypeCheckerVisitor.prototype.checkAssignable = function(node, s, t) {
   if (!$notnull_bool(this.types.isAssignable(s, t))) {
     var error = CompilerError.notAssignable(s, t);
-    this.compiler.reportWarning(node, error);
+    this.compiler.reportWarning(node, $assert_String(error));
   }
 }
 TypeCheckerVisitor.prototype.visitBlock = function(node) {
   this.type(node.statements);
   return this.types.voidType;
 }
 TypeCheckerVisitor.prototype.visitClassNode = function(node) {
   this.fail(node);
 }
 TypeCheckerVisitor.prototype.visitExpressionStatement = function(node) {
@@ skipping 51 matching lines @@
         var argument = (($0 = arguments.get$head()) && $0.is$Node());
         var argumentType = this.type(argument);
         this.checkAssignable(argument, argumentType, (($0 = formals.get$head()) && $0.is$Type()));
         formals = (($0 = formals.get$tail()) && $0.is$Link$Type());
         arguments = (($0 = arguments.get$tail()) && $0.is$Link$Node());
       }
       if (!$notnull_bool(formals.isEmpty())) {
         this.compiler.reportWarning(node, 'missing argument');
       }
       if (!$notnull_bool(arguments.isEmpty())) {
-        this.compiler.reportWarning(arguments.get$head(), 'additional arguments');
+        this.compiler.reportWarning((($0 = arguments.get$head()) && $0.is$Node()), 'additional arguments');
       }
       return funType.returnType;
     }
   }
   else {
     this.fail(node, ('unresolved send ' + selector.get$source() + ''));
   }
 }
 TypeCheckerVisitor.prototype.visitSendSet = function(node) {
   var $0;
@@ skipping 237 matching lines @@
     w.writeln("/**\n * Generates a dynamic call stub for a function.\n * Our goal is to create a stub method like this on-the-fly:\n *   function($0, $1, capture) { this($0, $1, true, capture); }\n *\n * This stub then replaces the dynamic one on Function, with one that is\n * specialized for that particular function, taking into account its default\n * arguments.\n */\nFunction.prototype.$genStub = function(argsLength, names) {\n  // TODO(jmesserly): only emit $genStub if actually needed\n\n  // Fast path: if no named arguments and arg count matches\n  if (this.length == argsLength && !names) {\n    return this;\n  }\n\n  function $throwArgMismatch() {\n    // TODO(jmesserly): better error message\n    $throw(new ClosureArgumentMismatchException());\n  }\n\n  var paramsNamed = this.$optional ? (this.$optional.length / 2) : 0;\n  var paramsBare = this.length - paramsNamed;\n  var argsNamed = names ? names.length : 0;\n  var argsBare = argsLength - argsNamed;\n\n  // Check we got the right number of arguments\n  if (argsBare < paramsBare || argsLength > this.length ||\n      argsNamed > paramsNamed) {\n    return $throwArgMismatch;\n  }\n\n  // First, fill in all of the default values\n  var p = new Array(paramsBare);\n  if (paramsNamed) {\n    p = p.concat(this.$optional.slice(paramsNamed));\n  }\n  // Fill in positional args\n  var a = new Array(argsLength);\n  for (var i = 0; i < argsBare; i++) {\n    p[i] = a[i] = '$' + i;\n  }\n  // Then overwrite with supplied values for optional args\n  var lastParameterIndex;\n  var namesInOrder = true;\n  for (var i = 0; i < argsNamed; i++) {\n    var name = names[i];\n    a[i + argsBare] = name;\n    var j = this.$optional.indexOf(name, 0);\n    if (j < 0 || j >= paramsNamed) {\n      return $throwArgMismatch;\n    } else if (lastParameterIndex && lastParameterIndex > j) {\n      namesInOrder = false;\n    }\n    p[j + paramsBare] = name;\n    lastParameterIndex = j;\n  }\n\n  if (this.length == argsLength && namesInOrder) {\n    // Fast path #2: named arguments, but they're in order.\n    return this;\n  }\n\n  // Note: using Function instead of 'eval' to get a clean scope.\n  // TODO(jmesserly): evaluate the performance of these stubs.\n  var f = 'function(' + a.join(',') + '){return $f(' + p.join(',') + ');}';\n  return new Function('$f', 'return ' + f + '').call(null, this);\n}");
   }
   if ($notnull_bool(this.useStackTraceOf)) {
     w.writeln("function $stackTraceOf(e) {\n  // TODO(jmesserly): we shouldn't be relying on the e.stack property.\n  // Need to mangle it.\n  return e.stack ? e.stack : null;\n}");
   }
   if ($notnull_bool(this.useToDartException)) {
     w.writeln("// Translate a JavaScript exception to a Dart exception\n// TODO(jmesserly): cross browser support. This is Chrome specific.\nfunction $toDartException(e) {\n  var res = e;\n  if (e instanceof TypeError) {\n    switch(e.type) {\n      case 'property_not_function':\n      case 'called_non_callable':\n        if (e.arguments[0] == null) {\n          res = new NullPointerException();\n        } else {\n          res = new ObjectNotClosureException();\n        }\n        break;\n      case 'non_object_property_call':\n      case 'non_object_property_load':\n        res = new NullPointerException();\n        break;\n      case 'undefined_method':\n        if (e.arguments[0] == 'call' || e.arguments[0] == 'apply') {\n          res = new ObjectNotClosureException();\n        } else {\n          // TODO(jmesserly): can this ever happen?\n          res = new NoSuchMethodException('', e.arguments[0], []);\n        }\n        break;\n    }\n  } else if (e instanceof RangeError) {\n    if (e.message.indexOf('call stack') >= 0) {\n      res = new StackOverflowException();\n    }\n  }\n  // TODO(jmesserly): setting the stack property is not a long term solution.\n  // Also it causes the exception to print as if it were a TypeError or\n  // RangeError, instead of using the proper toString.\n  res.stack = e.stack;\n  return res;\n}");
   }
   if ($notnull_bool(this.useNotNullBool)) {
     this.useThrow = true;
-    w.writeln("function $notnull_bool(test) {\n  return (test === true || test === false) ? test : test.is$bool();\n}");
+    w.writeln("function $notnull_bool(test) {\n  return (test === true || test === false) ? test : test.is$bool(); // TypeError\n}");
   }
   if ($notnull_bool(this.useAssert)) {
     this.useThrow = true;
     w.writeln("function $assert(test, text, url, line, column) {\n  if (typeof test == 'function') test = test();\n  if (!test) $throw(new AssertError(text, url, line, column));\n}");
   }
   if ($notnull_bool(this.useThrow)) {
     w.writeln("function $throw(e) {\n  // If e is not a value, we can use V8's captureStackTrace utility method.\n  // TODO(jmesserly): capture the stack trace on other JS engines.\n  if (e && (typeof e == 'object') && Error.captureStackTrace) {\n    // TODO(jmesserly): this will clobber the e.stack property\n    Error.captureStackTrace(e, $throw);\n  }\n  throw e;\n}");
   }
   if ($notnull_bool(this.useMap)) {
     w.writeln("function $map(items) {\n  var ret = new HashMapImplementation();\n  for (var i=0; i < items.length;) {\n    ret.$setindex(items[i++], items[i++]);\n  }\n  return ret;\n}");
@@ skipping 642 matching lines @@
           initializedFields.add$1(f.get$name());
         }
       }
     }
   }
   this._paramCode = [];
   var $list = this.method.get$parameters();
   for (var $i = 0;$i < $list.length; $i++) {
     var p = $list.$index($i);
     if ($notnull_bool($ne(initializers, null) && p.isInitializer)) {
-      var field = this.method.declaringType.getMember(p.get$name());
+      var field = this.method.declaringType.getMember($assert_String(p.get$name()));
       if ($notnull_bool(field == null)) {
         world.error('bad this parameter - no matching field', p.get$definition().get$span());
       }
       if (!$notnull_bool(field.get$isField())) {
         world.error(('"this.' + p.get$name() + '" does not refer to a field'), p.get$definition().get$span());
       }
       var paramValue = new Value(field.get$returnType(), p.get$name(), p.get$definition().get$span(), false);
       this._paramCode.add(paramValue.code);
       initializers.add$1(('this.' + field.get$jsname() + ' = ' + paramValue.code + ';'));
       initializedFields.add$1(p.get$name());
@@ skipping 22 matching lines @@
             world.error('only one initializer redirecting call is allowed', init.get$span());
           }
           initializerCall = init;
         }
         else if ((init instanceof BinaryExpression) && TokenKind.kindFromAssign(init.op.kind) == 0) {
           var left = init.x;
           if (!((left instanceof DotExpression) && (left.self instanceof ThisExpression) || (left instanceof VarExpression))) {
             world.error('invalid left side of initializer', left.get$span());
             continue;
           }
-          var f = this.method.declaringType.getMember(left.get$name().get$name());
+          var f = this.method.declaringType.getMember($assert_String(left.get$name().get$name()));
           if ($notnull_bool(f == null)) {
             world.error('bad initializer - no matching field', left.get$span());
             continue;
           }
           else if (!$notnull_bool(f.get$isField())) {
             world.error(('"' + left.get$name().get$name() + '" does not refer to a field'), left.get$span());
             continue;
           }
           initializedFields.add$1(f.get$name());
           this.writer.writeln(('this.' + f.get$jsname() + ' = ' + this.visitValue(init.y).code + ';'));
@@ skipping 847 matching lines @@
   var constructorName = '';
   if (node.name != null) {
     constructorName = node.name.name;
   }
   if ($notnull_bool($eq(constructorName, '') && !(typeRef instanceof GenericTypeReference)) && typeRef.names != null) {
     var names = ListFactory.ListFactory$from$factory(typeRef.names);
     constructorName = names.removeLast$0().get$name();
     if (names.length == 0) names = null;
     typeRef = new NameTypeReference(typeRef.isFinal, typeRef.get$name(), names, typeRef.get$span());
   }
-  var type = this.method.resolveType(typeRef, true);
+  var type = this.method.resolveType((typeRef && typeRef.is$TypeReference()), true);
   if ($notnull_bool(type.get$isTop())) {
     type = type.get$library().findTypeByName($assert_String(constructorName));
     constructorName = '';
   }
   var m = type.getConstructor$1(constructorName);
   if ($notnull_bool(m == null)) {
     var name = type.get$jsname();
     if ($notnull_bool(type.get$isVar())) {
       name = typeRef.get$name().get$name();
     }
@@ skipping 461 matching lines @@
       }
     }
   }
   return (ret && ret.is$Member());
 }
 Library.prototype.resolve = function() {
   if (this.name == null) {
     this.name = this.baseSource.filename;
     var index = this.name.lastIndexOf('/', this.name.length);
     if (index >= 0) {
-      this.name = this.name.substring(index + 1);
+      this.name = this.name.substring($assert_num(index + 1));
     }
     index = this.name.indexOf('.', 0);
     if (index > 0) {
-      this.name = this.name.substring(0, index);
+      this.name = this.name.substring(0, $assert_num(index));
     }
   }
   var $list = this.types.getValues();
   for (var $i = this.types.getValues().iterator$0(); $i.hasNext$0(); ) {
     var type = $i.next$0();
     type.resolve$0();
   }
 }
 Library.prototype.visitSources = function() {
   var visitor = new _LibraryVisitor(this);
@@ skipping 26 matching lines @@
 _LibraryVisitor.prototype.get$library = function() { return this.library; };
 _LibraryVisitor.prototype.get$isTop = function() { return this.isTop; };
 _LibraryVisitor.prototype.set$isTop = function(value) { return this.isTop = value; };
 _LibraryVisitor.prototype.addSourceFromName = function(name, span) {
   var filename = this.library.makeFullPath(name);
   if ($notnull_bool($eq(filename, this.library.baseSource.filename))) {
     world.error('library can not source itself', span);
     return;
   }
   else if (this.sources.some((function (s) {
-    return s.filename == filename;
+    return $eq(s.filename, filename);
   })
   )) {
     world.error(('file "' + filename + '" has already been sourced'), span);
     return;
   }
   var source = world.readFile(this.library.makeFullPath(name));
   this.sources.add(source);
 }
 _LibraryVisitor.prototype.addSource = function(source) {
   var $this = this; // closure support
@@ skipping 164 matching lines @@
 function Parameter(definition) {
   this.isInitializer = false
   this.definition = definition;
   // Initializers done
 }
 Parameter.prototype.is$Parameter = function(){return this;};
 Parameter.prototype.get$definition = function() { return this.definition; };
 Parameter.prototype.set$definition = function(value) { return this.definition = value; };
 Parameter.prototype.get$name = function() { return this.name; };
 Parameter.prototype.set$name = function(value) { return this.name = value; };
+Parameter.prototype.get$type = function() { return this.type; };
+Parameter.prototype.set$type = function(value) { return this.type = value; };
 Parameter.prototype.get$value = function() { return this.value; };
 Parameter.prototype.set$value = function(value) { return this.value = value; };
 Parameter.prototype.resolve = function(method, inType) {
   this.name = this.definition.name.name;
   if (this.name.startsWith('this.')) {
     this.name = this.name.substring(5);
     this.isInitializer = true;
   }
   this.type = inType.resolveType(this.definition.type, false);
   if ($notnull_bool(method.get$isStatic() && this.type.get$hasTypeParams())) {
@@ skipping 17 matching lines @@
 Parameter.prototype.genValue = function(method, context) {
   var $0;
   if (this.definition.value == null || this.value != null) return;
   if (context == null) {
     context = new MethodGenerator(method, null);
   }
   this.value = (($0 = this.definition.value.visit(context)) && $0.is$Value());
   this.value = this.value.convertTo(context, this.type, this.definition.value, false);
 }
 Parameter.prototype.copyWithNewType = function(newType) {
+  var $0;
   var ret = new Parameter(this.definition);
-  ret.type = newType;
-  ret.name = this.name;
+  ret.set$type(newType);
+  ret.set$name(this.name);
   ret.isInitializer = this.isInitializer;
   return (ret && ret.is$Parameter());
 }
 Parameter.prototype.get$isOptional = function() {
   return this.definition != null && this.definition.value != null;
 }
 Parameter.prototype.copyWithNewType$1 = function($0) {
   return this.copyWithNewType(($0 && $0.is$lang_Type()));
 };
 Parameter.prototype.genValue$2 = function($0, $1) {
@@ skipping 85 matching lines @@
 Member.prototype.get$definition = function() {
   return null;
 }
 Member.prototype.get$parameters = function() {
   return [];
 }
 Member.prototype.canInvoke = function(context, args) {
   return $notnull_bool(this.get$canGet() && new Value(this.get$returnType(), null, null, true).canInvoke(context, '\$call', args));
 }
 Member.prototype.invoke = function(context, node, target, args, isDynamic) {
+  var $0;
   var newTarget = this._get(context, node, target, isDynamic);
-  return newTarget.invoke$5(context, '\$call', node, args, isDynamic);
+  return (($0 = newTarget.invoke$5(context, '\$call', node, args, isDynamic)) && $0.is$Value());
 }
 Member.prototype.override = function(other) {
   if ($notnull_bool(this.get$isStatic())) {
     world.error('static members can not hide parent members', this.get$span(), other.get$span());
     return false;
   }
   else if ($notnull_bool(other.get$isStatic())) {
     world.error('can not override static member', this.get$span(), other.get$span());
     return false;
   }
@@ skipping 44 matching lines @@
   return this.resolve(($0 && $0.is$lang_Type()));
 };
 // ********** Code for TypeMember **************
 function TypeMember(type) {
   this.type = type;
   Member.call(this, type.name, type.library.topType);
   // Initializers done
 }
 $inherits(TypeMember, Member);
 TypeMember.prototype.is$TypeMember = function(){return this;};
+TypeMember.prototype.get$type = function() { return this.type; };
 TypeMember.prototype.get$span = function() {
   return this.type.definition.span;
 }
 TypeMember.prototype.get$isStatic = function() {
   return true;
 }
 TypeMember.prototype.get$returnType = function() {
   return world.varType;
 }
 TypeMember.prototype.canInvoke = function(context, args) {
@@ skipping 47 matching lines @@
   this.definition = definition;
   this.value = value;
   this.isNative = false;
   Member.call(this, name, declaringType);
   // Initializers done
 }
 $inherits(FieldMember, Member);
 FieldMember.prototype.is$FieldMember = function(){return this;};
 FieldMember.prototype.get$definition = function() { return this.definition; };
 FieldMember.prototype.get$value = function() { return this.value; };
+FieldMember.prototype.get$type = function() { return this.type; };
+FieldMember.prototype.set$type = function(value) { return this.type = value; };
 FieldMember.prototype.get$isStatic = function() { return this.isStatic; };
 FieldMember.prototype.set$isStatic = function(value) { return this.isStatic = value; };
 FieldMember.prototype.get$isNative = function() { return this.isNative; };
 FieldMember.prototype.set$isNative = function(value) { return this.isNative = value; };
 FieldMember.prototype.override = function(other) {
   if (!$notnull_bool(Member.prototype.override.call(this, other))) return false;
   if ($notnull_bool(other.get$isProperty())) {
     return true;
   }
   else {
@@ skipping 67 matching lines @@
   if (this.value == null) return null;
   if (this._computedValue == null) {
     if ($notnull_bool(this._computing)) {
       world.error('circular reference', this.value.span);
       return null;
     }
     this._computing = true;
     var finalMethod = new MethodMember('final_context', this.declaringType, null);
     finalMethod.isStatic = true;
     var finalGen = new MethodGenerator(finalMethod, null);
-    this._computedValue = (($0 = this.value.visit(finalGen)) && $0.is$Value());
+    this._computedValue = (($0 = this.value.visit((finalGen && finalGen.is$TreeVisitor()))) && $0.is$Value());
     if (!$notnull_bool(this._computedValue.get$isConst())) {
       if ($notnull_bool(this.isStatic)) {
         world.error('non constant static field must be initialized in functions', this.value.span);
       }
       else {
         world.error('non constant field must be initialized in constructor', this.value.span);
       }
     }
     if ($notnull_bool(this.isStatic)) {
       this._computedValue = world.gen.globalForStaticField(this, this._computedValue, [this._computedValue]);
@@ skipping 652 matching lines @@
           value = this.parameters.$index(j).get$value();
         }
       }
       this.generator._scope._vars.$setindex(name, value);
     }
     var $list = this.definition.initializers;
     for (var $i = 0;$i < $list.length; $i++) {
       var init = $list.$index($i);
       if ((init instanceof CallExpression)) {
         var delegateArgs = this.generator._makeArgs((($0 = init.get$arguments()) && $0.is$List$ArgumentNode()));
-        var value = this.initDelegate.invoke(this.generator, node, target, delegateArgs, false);
+        var value = this.initDelegate.invoke(this.generator, node, target, (delegateArgs && delegateArgs.is$Arguments()), false);
         if ((init.target instanceof ThisExpression)) {
           return (value && value.is$Value());
         }
         else {
           if ((value instanceof GlobalValue)) {
             value = value.exp;
           }
           var $list0 = value.fields.getKeys();
           for (var $i0 = value.fields.getKeys().iterator$0(); $i0.hasNext$0(); ) {
             var fname = $i0.next$0();
@@ skipping 461 matching lines @@
     }
   }
   return returnValue;
 }
 MemberSet.prototype.invoke = function(context, node, target, args, isDynamic) {
   var $0;
   if ($notnull_bool(this.isVar && !$notnull_bool(this.get$isOperator()))) {
     return this.invokeOnVar(context, node, target, args);
   }
   if (this.members.length == 1) {
-    return this.members.$index(0).invoke$5(context, node, target, args, isDynamic);
+    return (($0 = this.members.$index(0).invoke$5(context, node, target, args, isDynamic)) && $0.is$Value());
   }
   var targets = this.members.filter((function (m) {
     return m.canInvoke$2(context, args);
   })
   );
   if (targets.length == 1) {
     return (($0 = targets.$index(0).invoke$5(context, node, target, args, isDynamic)) && $0.is$Value());
   }
   var returnValue = null;
   for (var $i = targets.iterator$0(); $i.hasNext$0(); ) {
     var member = $i.next$0();
     var res = member.invoke$4$isDynamic(context, node, target, args, true);
-    returnValue = this._tryUnion(returnValue, res, node);
+    returnValue = this._tryUnion(returnValue, (res && res.is$Value()), node);
   }
   if (returnValue == null) {
     return this._makeError(node, target, 'method');
   }
   if (returnValue.code == null) {
     if ($notnull_bool(this.get$isOperator())) {
       return target.invokeSpecial(this.name, args, returnValue.type);
     }
     else {
       return this.invokeOnVar(context, node, target, args);
@@ skipping 143 matching lines @@
 SourceFile.prototype.is$SourceFile = function(){return this;};
 SourceFile.prototype.is$Comparable = function(){return this;};
 SourceFile.prototype.get$text = function() {
   return this._text;
 }
 SourceFile.prototype.get$lineStarts = function() {
   if (this._lineStarts == null) {
     var starts = [0];
     var index = 0;
     while (index < this.get$text().length) {
-      index = this.get$text().indexOf('\n', index) + 1;
+      index = this.get$text().indexOf('\n', $assert_num(index)) + 1;
       if (index <= 0) break;
       starts.add$1(index);
     }
     starts.add$1(this.get$text().length + 1);
     this._lineStarts = (starts && starts.is$List$int());
   }
   return this._lineStarts;
 }
 SourceFile.prototype.getLine = function(position) {
   var starts = this.get$lineStarts();
   for (var i = 0;
    i < starts.length; i++) {
     if (starts.$index(i) > position) return i - 1;
   }
   world.internalError('bad position');
 }
 SourceFile.prototype.getColumn = function(line, position) {
   return position - $assert_num(this.get$lineStarts().$index(line));
 }
 SourceFile.prototype.getLocationMessage = function(message, start, end, includeText) {
   var line = this.getLine(start);
   var column = this.getColumn($assert_num(line), start);
   var buf = new StringBufferImpl(('' + this.filename + ':' + (line + 1) + ':' + (column + 1) + ': ' + message + ''));
   if ($notnull_bool(includeText)) {
     buf.add$1('\n');
     var textLine;
     if ((line + 2) < this._lineStarts.length) {
-      textLine = this.get$text().substring(this._lineStarts.$index(line), this._lineStarts.$index(line + 1));
+      textLine = this.get$text().substring($assert_num(this._lineStarts.$index(line)), $assert_num(this._lineStarts.$index(line + 1)));
     }
     else {
-      textLine = this.get$text().substring(this._lineStarts.$index(line)) + '\n';
+      textLine = this.get$text().substring($assert_num(this._lineStarts.$index(line))) + '\n';
     }
     buf.add$1(textLine);
     var i = 0;
     for (; i < $assert_num(column); i++) {
       buf.add$1(' ');
     }
     var toColumn = Math.min($assert_num(column + (end - start)), textLine.length);
     for (; i < toColumn; i++) {
       buf.add$1('^');
     }
@@ skipping 1978 matching lines @@
       values.add$1(this.expression());
     }
     else {
       values.add$1();
     }
   }
   this._eatSemicolon();
   return new VariableDefinition(modifiers, type, names, values, this._makeSpan($assert_num(start)));
 }
 lang_Parser.prototype.finishDefinition = function(start, modifiers, di) {
+  var $0;
   switch (this._peek()) {
     case 2/*TokenKind.LPAREN*/:
 
       var formals = this.formalParameterList();
       var inits = null;
       if ($notnull_bool(this._maybeEat(8/*TokenKind.COLON*/))) {
         inits = this.initializers();
       }
       var body = this.functionBody(false);
       if ($notnull_bool(di.get$name() == null)) {
-        di.name = di.type.get$name();
+        di.set$name(di.type.get$name());
       }
       return new FunctionDefinition(modifiers, di.type, di.get$name(), formals, inits, body, this._makeSpan($assert_num(start)));
 
     case 20/*TokenKind.ASSIGN*/:
 
       this._eat(20/*TokenKind.ASSIGN*/);
       var value = this.expression();
       return this.finishField(start, modifiers, di.type, di.get$name(), value);
 
     case 11/*TokenKind.COMMA*/:
@@ skipping 701 matching lines @@
 lang_Parser.prototype.stringInterpolation = function() {
   var start = this._peekToken.start;
   var lits = [];
   var startQuote = null, endQuote = null;
   while ($notnull_bool(this._peekKind(66/*TokenKind.INCOMPLETE_STRING*/))) {
     var token = this._lang_next();
     var text = token.get$text();
     if ($notnull_bool(startQuote == null)) {
       if ($notnull_bool(isMultilineString($assert_String(text)))) {
         endQuote = text.substring$2(0, 3);
-        startQuote = endQuote + '\n';
+        startQuote = $add(endQuote, '\n');
       }
       else {
         startQuote = endQuote = text.$index(0);
       }
-      text = text.substring$2(0, text.length - 1) + endQuote;
+      text = $add(text.substring$2(0, text.length - 1), endQuote);
     }
     else {
-      text = startQuote + text.substring$2(0, text.length - 1) + endQuote;
+      text = $add($add(startQuote, text.substring$2(0, text.length - 1)), endQuote);
     }
     lits.add$1(this.makeStringLiteral($assert_String(text), token.get$span()));
     if ($notnull_bool(this._maybeEat(6/*TokenKind.LBRACE*/))) {
       lits.add$1(this.expression());
       this._eat(7/*TokenKind.RBRACE*/);
     }
     else {
       var id = this.identifier();
       lits.add$1(new VarExpression(id, id.get$span()));
     }
   }
   var tok = this._lang_next();
   if ($notnull_bool($ne(tok.kind, 58/*TokenKind.STRING*/))) {
     this._errorExpected('interpolated string');
   }
-  var text = startQuote + tok.get$text();
+  var text = $add(startQuote, tok.get$text());
   lits.add$1(this.makeStringLiteral($assert_String(text), tok.get$span()));
   var span = this._makeSpan(start);
   return new LiteralExpression(lits, this._stringTypeRef((span && span.is$SourceSpan())), '\$\$\$', (span && span.is$SourceSpan()));
 }
 lang_Parser.prototype.makeStringLiteral = function(text, span) {
   return new LiteralExpression(text, this._stringTypeRef(span), text, span);
 }
 lang_Parser.prototype.stringLiteralExpr = function() {
   var token = this._lang_next();
   return this.makeStringLiteral(token.get$text(), token.get$span());
@@ skipping 335 matching lines @@
     names.add$1(this.identifier());
   }
   var typeRef = new NameTypeReference(isFinal, name, names, this._makeSpan(start));
   if ($notnull_bool(this._peekKind(52/*TokenKind.LT*/))) {
     return this.addTypeArguments((typeRef && typeRef.is$TypeReference()), depth);
   }
   else {
     return typeRef;
   }
 }
+lang_Parser.prototype.get$type = function() {
+  return lang_Parser.prototype.type.bind(this);
+}
 lang_Parser.prototype.formalParameter = function(inOptionalBlock) {
   var start = this._peekToken.start;
   var isThis = false;
   var isRest = false;
   var di = this.declaredIdentifier(false);
   var type = di.type;
   var name = di.get$name();
   var value = null;
   if ($notnull_bool(this._maybeEat(20/*TokenKind.ASSIGN*/))) {
     if (!$notnull_bool(inOptionalBlock)) {
@@ skipping 228 matching lines @@
 $inherits(lang_Expression, lang_Node);
 lang_Expression.prototype.is$lang_Expression = function(){return this;};
 // ********** Code for TypeReference **************
 function TypeReference(span, type) {
   this.type = type;
   lang_Node.call(this, span);
   // Initializers done
 }
 $inherits(TypeReference, lang_Node);
 TypeReference.prototype.is$TypeReference = function(){return this;};
+TypeReference.prototype.get$type = function() { return this.type; };
+TypeReference.prototype.set$type = function(value) { return this.type = value; };
 TypeReference.prototype.visit = function(visitor) {
   return visitor.visitTypeReference(this);
 }
 TypeReference.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for DirectiveDefinition **************
 function DirectiveDefinition(name, arguments, span) {
   this.name = name;
   this.arguments = arguments;
@@ skipping 59 matching lines @@
 // ********** Code for VariableDefinition **************
 function VariableDefinition(modifiers, type, names, values, span) {
   this.modifiers = modifiers;
   this.type = type;
   this.names = names;
   this.values = values;
   Definition.call(this, span);
   // Initializers done
 }
 $inherits(VariableDefinition, Definition);
+VariableDefinition.prototype.get$type = function() { return this.type; };
+VariableDefinition.prototype.set$type = function(value) { return this.type = value; };
 VariableDefinition.prototype.visit = function(visitor) {
   return visitor.visitVariableDefinition(this);
 }
 VariableDefinition.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for FunctionDefinition **************
 function FunctionDefinition(modifiers, returnType, name, formals, initializers, body, span) {
   this.modifiers = modifiers;
   this.returnType = returnType;
@@ skipping 364 matching lines @@
   this.isConst = isConst;
   this.type = type;
   this.name = name;
   this.arguments = arguments;
   lang_Expression.call(this, span);
   // Initializers done
 }
 $inherits(lang_NewExpression, lang_Expression);
 lang_NewExpression.prototype.get$isConst = function() { return this.isConst; };
 lang_NewExpression.prototype.set$isConst = function(value) { return this.isConst = value; };
+lang_NewExpression.prototype.get$type = function() { return this.type; };
+lang_NewExpression.prototype.set$type = function(value) { return this.type = value; };
 lang_NewExpression.prototype.get$name = function() { return this.name; };
 lang_NewExpression.prototype.set$name = function(value) { return this.name = value; };
 lang_NewExpression.prototype.get$arguments = function() { return this.arguments; };
 lang_NewExpression.prototype.set$arguments = function(value) { return this.arguments = value; };
 lang_NewExpression.prototype.visit = function(visitor) {
   return visitor.visitNewExpression(this);
 }
 lang_NewExpression.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for ListExpression **************
 function ListExpression(isConst, type, values, span) {
   this.isConst = isConst;
   this.type = type;
   this.values = values;
   lang_Expression.call(this, span);
   // Initializers done
 }
 $inherits(ListExpression, lang_Expression);
 ListExpression.prototype.get$isConst = function() { return this.isConst; };
 ListExpression.prototype.set$isConst = function(value) { return this.isConst = value; };
+ListExpression.prototype.get$type = function() { return this.type; };
+ListExpression.prototype.set$type = function(value) { return this.type = value; };
 ListExpression.prototype.visit = function(visitor) {
   return visitor.visitListExpression(this);
 }
 ListExpression.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for MapExpression **************
 function MapExpression(isConst, type, items, span) {
   this.isConst = isConst;
   this.type = type;
   this.items = items;
   lang_Expression.call(this, span);
   // Initializers done
 }
 $inherits(MapExpression, lang_Expression);
 MapExpression.prototype.get$isConst = function() { return this.isConst; };
 MapExpression.prototype.set$isConst = function(value) { return this.isConst = value; };
+MapExpression.prototype.get$type = function() { return this.type; };
+MapExpression.prototype.set$type = function(value) { return this.type = value; };
 MapExpression.prototype.visit = function(visitor) {
   return visitor.visitMapExpression(this);
 }
 MapExpression.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for ConditionalExpression **************
 function ConditionalExpression(test, trueBranch, falseBranch, span) {
   this.test = test;
   this.trueBranch = trueBranch;
@@ skipping 10 matching lines @@
 };
 // ********** Code for IsExpression **************
 function IsExpression(isTrue, x, type, span) {
   this.isTrue = isTrue;
   this.x = x;
   this.type = type;
   lang_Expression.call(this, span);
   // Initializers done
 }
 $inherits(IsExpression, lang_Expression);
+IsExpression.prototype.get$type = function() { return this.type; };
+IsExpression.prototype.set$type = function(value) { return this.type = value; };
 IsExpression.prototype.visit = function(visitor) {
   return visitor.visitIsExpression(this);
 }
 IsExpression.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for ParenExpression **************
 function ParenExpression(body, span) {
   this.body = body;
   lang_Expression.call(this, span);
@@ skipping 79 matching lines @@
 function LiteralExpression(value, type, text, span) {
   this.value = value;
   this.type = type;
   this.text = text;
   lang_Expression.call(this, span);
   // Initializers done
 }
 $inherits(LiteralExpression, lang_Expression);
 LiteralExpression.prototype.get$value = function() { return this.value; };
 LiteralExpression.prototype.set$value = function(value) { return this.value = value; };
+LiteralExpression.prototype.get$type = function() { return this.type; };
+LiteralExpression.prototype.set$type = function(value) { return this.type = value; };
 LiteralExpression.prototype.get$text = function() { return this.text; };
 LiteralExpression.prototype.set$text = function(value) { return this.text = value; };
 LiteralExpression.prototype.visit = function(visitor) {
   return visitor.visitLiteralExpression(this);
 }
 LiteralExpression.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for NameTypeReference **************
 function NameTypeReference(isFinal, name, names, span) {
@@ skipping 65 matching lines @@
 function FormalNode(isThis, isRest, type, name, value, span) {
   this.isThis = isThis;
   this.isRest = isRest;
   this.type = type;
   this.name = name;
   this.value = value;
   lang_Node.call(this, span);
   // Initializers done
 }
 $inherits(FormalNode, lang_Node);
+FormalNode.prototype.get$type = function() { return this.type; };
+FormalNode.prototype.set$type = function(value) { return this.type = value; };
 FormalNode.prototype.get$name = function() { return this.name; };
 FormalNode.prototype.set$name = function(value) { return this.name = value; };
 FormalNode.prototype.get$value = function() { return this.value; };
 FormalNode.prototype.set$value = function(value) { return this.value = value; };
 FormalNode.prototype.visit = function(visitor) {
   return visitor.visitFormalNode(this);
 }
 FormalNode.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
@@ skipping 45 matching lines @@
 TypeParameter.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for lang_Identifier **************
 function lang_Identifier(name, span) {
   this.name = name;
   lang_Node.call(this, span);
   // Initializers done
 }
 $inherits(lang_Identifier, lang_Node);
+lang_Identifier.prototype.is$lang_Identifier = function(){return this;};
 lang_Identifier.prototype.get$name = function() { return this.name; };
 lang_Identifier.prototype.set$name = function(value) { return this.name = value; };
 lang_Identifier.prototype.visit = function(visitor) {
   return visitor.visitIdentifier(this);
 }
 lang_Identifier.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for DeclaredIdentifier **************
 function DeclaredIdentifier(type, name, span) {
   this.type = type;
   this.name = name;
   lang_Expression.call(this, span);
   // Initializers done
 }
 $inherits(DeclaredIdentifier, lang_Expression);
 DeclaredIdentifier.prototype.is$DeclaredIdentifier = function(){return this;};
+DeclaredIdentifier.prototype.get$type = function() { return this.type; };
+DeclaredIdentifier.prototype.set$type = function(value) { return this.type = value; };
 DeclaredIdentifier.prototype.get$name = function() { return this.name; };
 DeclaredIdentifier.prototype.set$name = function(value) { return this.name = value; };
 DeclaredIdentifier.prototype.visit = function(visitor) {
   return visitor.visitDeclaredIdentifier(this);
 }
 DeclaredIdentifier.prototype.visit$1 = function($0) {
   return this.visit(($0 && $0.is$TreeVisitor()));
 };
 // ********** Code for lang_Type **************
 function lang_Type(name) {
@@ skipping 314 matching lines @@
 ParameterType.prototype.resolveTypeParams$1 = function($0) {
   return this.resolveTypeParams(($0 && $0.is$ConcreteType()));
 };
 // ********** Code for NonNullableType **************
 function NonNullableType(type) {
   this.type = type;
   lang_Type.call(this, type.name);
   // Initializers done
 }
 $inherits(NonNullableType, lang_Type);
+NonNullableType.prototype.get$type = function() { return this.type; };
 NonNullableType.prototype.get$isNullable = function() {
   return false;
 }
 NonNullableType.prototype.get$isBool = function() {
   return this.type.get$isBool();
 }
 NonNullableType.prototype.get$isUsed = function() {
   return false;
 }
 NonNullableType.prototype.isSubtypeOf = function(other) {
@@ skipping 684 matching lines @@
   }
   return null;
 }
 DefinedType.prototype.getMember = function(memberName) {
   var $0;
   var member = (($0 = this.members.$index(memberName)) && $0.is$Member());
   if (member != null) {
     var parentMember = this.getMemberInParents(memberName);
     if ($notnull_bool($ne(parentMember, null))) {
       if (!$notnull_bool(member.get$isPrivate()) || $eq(member.get$library(), parentMember.get$library())) {
-        member.override(parentMember);
+        member.override((parentMember && parentMember.is$Member()));
       }
     }
     return member;
   }
   if ($notnull_bool(this.get$isTop())) {
     var libType = this.library.findTypeByName(memberName);
     if ($notnull_bool($ne(libType, null))) {
       return libType.get$typeMember();
     }
   }
@@ skipping 302 matching lines @@
   this.isSuper = false
   this.isType = false
   this.type = type;
   this.code = code;
   this.span = span;
   this.needsTemp = needsTemp;
   // Initializers done
   if (this.type == null) world.internalError('type passed as null', this.span);
 }
 Value.prototype.is$Value = function(){return this;};
+Value.prototype.get$type = function() { return this.type; };
+Value.prototype.set$type = function(value) { return this.type = value; };
 Value.prototype.get$span = function() { return this.span; };
 Value.prototype.set$span = function(value) { return this.span = value; };
 Value.prototype.get$_typeIsVarOrParameterType = function() {
   return $notnull_bool(this.type.get$isVar() || (this.type instanceof ParameterType));
 }
 Value.prototype.get$isConst = function() {
   return false;
 }
 Value.prototype.get$canonicalCode = function() {
   return null;
@@ skipping 110 matching lines @@
   var callMethod = toType.getCallMethod();
   if ($notnull_bool($ne(callMethod, null))) {
     var arity = callMethod.get$parameters().length;
     var myCall = this.type.getCallMethod();
     if ($notnull_bool(myCall == null || myCall.get$parameters().length != arity)) {
       return true;
     }
   }
   if ($notnull_bool(options.enableTypeChecks)) {
     var fromType = this.type;
-    if ($notnull_bool(this.type.get$isVar() && this.code != 'null')) {
+    if ($notnull_bool(this.type.get$isVar() && (this.code != 'null' || !$notnull_bool(toType.get$isNullable())))) {
       fromType = world.objectType;
     }
     var bothNum = $notnull_bool(this.type.get$isNum() && toType.get$isNum());
     return $notnull_bool(fromType.isSubtypeOf(toType) || bothNum);
   }
   return false;
 }
 Value.prototype.convertTo = function(context, toType, node, isDynamic) {
   var $0;
   var checked = !$notnull_bool(isDynamic);
@@ skipping 11 matching lines @@
     }
     else if ($notnull_bool(this._isDomCallback(toType) && !$notnull_bool(this._isDomCallback(this.type)))) {
       return this._wrapDomCallback(toType, arity);
     }
   }
   var fromType = this.type;
   if ($notnull_bool(this.type.get$isVar() && (this.code != 'null' || !$notnull_bool(toType.get$isNullable())))) {
     fromType = world.objectType;
   }
   var bothNum = $notnull_bool(this.type.get$isNum() && toType.get$isNum());
-  if ($notnull_bool($notnull_bool(!$notnull_bool(checked) || fromType.isSubtypeOf(toType)) || bothNum)) {
+  if ($notnull_bool(fromType.isSubtypeOf(toType) || bothNum)) {
     return this;
   }
   if ($notnull_bool(checked && !$notnull_bool(toType.isSubtypeOf(this.type)))) {
     this.convertWarning(toType, node);
   }
   if ($notnull_bool(options.enableTypeChecks)) {
     return this._typeAssert(context, toType, node);
   }
   else {
     return this;
   }
 }
 Value.prototype._isDomCallback = function(toType) {
   return ((toType.get$definition() instanceof FunctionTypeDefinition) && $eq(toType.get$library(), world.get$dom()));
 }
 Value.prototype._wrapDomCallback = function(toType, arity) {
   return new Value(toType, ('\$wrap_call\$' + arity + '(' + this.code + ')'), this.span, true);
 }
 Value.prototype._typeAssert = function(context, toType, node) {
   if ((toType instanceof ParameterType)) {
     var p = (toType && toType.is$ParameterType());
     toType = p.extendsType;
   }
+  if (toType.getCallMethod() != null) {
+    return this;
+  }
   if ($notnull_bool(toType.get$isObject() || toType.get$isVar())) {
     world.internalError(('We thought ' + this.type.name + ' is not a subtype of ' + toType.name + '?'));
   }
   if ($notnull_bool(toType.get$isNum())) toType = world.numType;
   var check;
   if ($notnull_bool(toType.get$isVoid())) {
     check = ('\$assert_void(' + this.code + ')');
     if (toType.typeCheckCode == null) {
       toType.typeCheckCode = "function $assert_void(x) {\n  return x == null ? x : x.is$void(); // throws TypeError\n}";
     }
@@ skipping 64 matching lines @@
     for (var i = 0;
      i < args.get$length(); i++) {
       argsCode.add$1(args.values.$index(i).code);
     }
     pos = Strings.join((argsCode && argsCode.is$List$String()), ", ");
   }
   var noSuchArgs = [new Value(world.stringType, ('"' + name + '"'), node.span, true), new Value(world.listType, ('[' + pos + ']'), node.span, true)];
   return this._resolveMember(context, 'noSuchMethod', node, false).invoke$4(context, node, this, new Arguments(null, noSuchArgs));
 }
 Value.prototype.invokeSpecial = function(name, args, returnType) {
-  $assert(name.startsWith('\$'), "name.startsWith('\\$')", "value.dart", 449, 12);
-  $assert(!$notnull_bool(args.get$hasNames()), "!args.hasNames", "value.dart", 450, 12);
+  $assert(name.startsWith('\$'), "name.startsWith('\\$')", "value.dart", 455, 12);
+  $assert(!$notnull_bool(args.get$hasNames()), "!args.hasNames", "value.dart", 456, 12);
   var argsString = args.getCode();
   if (name == '\$index' || name == '\$setindex') {
     return new Value(returnType, ('' + this.code + '.' + name + '(' + argsString + ')'), this.span, true);
   }
   else {
     if (argsString.length > 0) argsString = (', ' + argsString + '');
     world.gen.corejs.useOperator(name);
     return new Value(returnType, ('' + name + '(' + this.code + '' + argsString + ')'), this.span, true);
   }
 }
@@ skipping 178 matching lines @@
 };
 // ********** Code for BareValue **************
 function BareValue(home, outermost, span) {
   this.home = home;
   Value.call(this, outermost.method.declaringType, null, span, false);
   // Initializers done
   this.isType = outermost.get$isStatic();
 }
 $inherits(BareValue, Value);
 BareValue.prototype._tryResolveMember = function(context, name) {
-  $assert($eq(context, this.home), "context == home", "value.dart", 654, 12);
+  $assert($eq(context, this.home), "context == home", "value.dart", 660, 12);
   var member = this.type.resolveMember(name);
   if ($notnull_bool($ne(member, null))) {
-    $assert(this.code == null, "code == null", "value.dart", 659, 14);
+    $assert(this.code == null, "code == null", "value.dart", 665, 14);
     if ($notnull_bool(this.isType)) {
       this.code = this.type.get$jsname();
     }
     else {
       this.code = this.home._makeThisCode();
     }
     return member;
   }
   member = this.home.get$library().lookup(name, this.span);
   if ($notnull_bool($ne(member, null))) {
@@ skipping 435 matching lines @@
         else {
           if (!$notnull_bool(ignoreUnrecognizedFlags)) {
             print(('unrecognized flag: "' + arg + '"'));
           }
         }
 
     }
   }
   if (!$notnull_bool(passedLibDir) && !$notnull_bool(files.fileExists(this.libDir))) {
     var temp = 'frog/lib';
-    if ($notnull_bool(files.fileExists(temp))) {
+    if ($notnull_bool(files.fileExists($assert_String(temp)))) {
       this.libDir = $assert_String(temp);
     }
     else {
       this.libDir = 'lib';
     }
   }
 }
 // ********** Code for LibraryReader **************
 function LibraryReader() {
   // Initializers done
   this._specialLibs = $map(['dart:core', joinPaths(options.libDir, 'corelib.dart'), 'dart:coreimpl', joinPaths(options.libDir, 'corelib_impl.dart'), 'dart:html', joinPaths(options.libDir, '../../client/html/release/html.dart'), 'dart:dom', joinPaths(options.libDir, 'dom/dom.dart'), 'dart:json', joinPaths(options.libDir, 'json.dart')]);
 }
 LibraryReader.prototype.readFile = function(fullname) {
   var filename = this._specialLibs.$index(fullname);
   if ($notnull_bool(filename == null)) {
     filename = fullname;
   }
-  if ($notnull_bool(world.files.fileExists(filename))) {
-    return new SourceFile(filename, world.files.readAll(filename));
+  if ($notnull_bool(world.files.fileExists($assert_String(filename)))) {
+    return new SourceFile(filename, world.files.readAll($assert_String(filename)));
   }
   else {
     world.error(('File not found: ' + filename + ''));
     return new SourceFile(filename, '');
   }
 }
 // ********** Code for VarMember **************
 function VarMember(name) {
   this.name = name;
   // Initializers done
@@ skipping 126 matching lines @@
   return VarMember.prototype.invoke.call(this, context, node, target, args);
 }
 VarMethodSet.prototype._invokeMembers = function(context, node) {
   if (this._fallbackStubs != null) return;
   var objectStub = null;
   this._fallbackStubs = [];
   var $list = this.members;
   for (var $i = 0;$i < $list.length; $i++) {
     var member = $list.$index($i);
     var target = new Value(member.declaringType, 'this', node.span, true);
-    var result = member.invoke$4(context, node, target, this.args);
+    var result = member.invoke$4$isDynamic(context, node, target, this.args, true);
     var stub = new VarMethodStub(this.name, member, this.args, result);
     var type = member.declaringType;
     if ($notnull_bool(type.get$isObject())) {
       objectStub = stub;
     }
     else if ($ne(type.get$library(), world.get$dom())) {
       VarMethodSet._addVarStub((type && type.is$lang_Type()), (stub && stub.is$VarMember()));
     }
     else {
       this._fallbackStubs.add(stub);
@@ skipping 126 matching lines @@
 function lang_compile(homedir, args, files) {
   parseOptions(homedir, args, files);
   initializeWorld(files);
   var success = world.compile();
   if (options.outfile != null) {
     if ($notnull_bool(success)) {
       var code = world.getGeneratedCode();
       if (!options.outfile.endsWith('.js')) {
         code = '#!/usr/bin/env node\n' + code;
       }
-      world.files.writeString(options.outfile, code);
+      world.files.writeString(options.outfile, $assert_String(code));
     }
     else {
       world.files.writeString(options.outfile, "throw 'Sorry, but I could not generate reasonable code to run.\\n';");
     }
   }
   return $assert_bool(success);
 }
 var options;
 function parseOptions(homedir, args, files) {
   $assert(options == null, "options == null", "frog_options.dart", 10, 10);
@@ skipping 152 matching lines @@
       INTERFACE,
       LIBRARY,
       NATIVE,
       NEGATE,
       OPERATOR,
       SET,
       SOURCE,
       STATIC,
       TYPEDEF ]*/;
 RunEntry(function () {main();}, []);