Disable closure wrapping by default

lib/runtime/dart/_internal.js

 var _internal;
 (function(exports) {
   'use strict';
   class EfficientLength extends core.Object {}
   let ListIterable$ = dart.generic(function(E) {
     class ListIterable extends collection.IterableBase$(E) {
       ListIterable() {
         super.IterableBase();
       }
       get iterator() {
@@ skipping 482 matching lines @@
   });
   let _ExpandFunction = _ExpandFunction$();
   let ExpandIterable$ = dart.generic(function(S, T) {
     class ExpandIterable extends collection.IterableBase$(T) {
       ExpandIterable(iterable$, f$) {
         this[_iterable] = iterable$;
         this[_f] = f$;
         super.IterableBase();
       }
       get iterator() {
-        return new (ExpandIterator$(S, T))(this[_iterable].iterator, dart.closureWrap(this[_f], "(S) → Iterable<T>"));
+        return new (ExpandIterator$(S, T))(this[_iterable].iterator, dart.as(this[_f], dart.throw_("Unimplemented type (S) → Iterable<T>")));
       }
     }
     return ExpandIterable;
   });
   let ExpandIterable = ExpandIterable$();
   let _currentExpansion = dart.JsSymbol('_currentExpansion');
   let _nextExpansion = dart.JsSymbol('_nextExpansion');
   let ExpandIterator$ = dart.generic(function(S, T) {
     class ExpandIterator extends core.Object {
       ExpandIterator(iterator$, f$) {
@@ skipping 94 matching lines @@
   });
   let TakeIterator = TakeIterator$();
   let TakeWhileIterable$ = dart.generic(function(E) {
     class TakeWhileIterable extends collection.IterableBase$(E) {
       TakeWhileIterable(iterable$, f$) {
         this[_iterable] = iterable$;
         this[_f] = f$;
         super.IterableBase();
       }
       get iterator() {
-        return new (TakeWhileIterator$(E))(this[_iterable].iterator, dart.closureWrap(this[_f], "(E) → bool"));
+        return new (TakeWhileIterator$(E))(this[_iterable].iterator, dart.as(this[_f], dart.throw_("Unimplemented type (E) → bool")));
       }
     }
     return TakeWhileIterable;
   });
   let TakeWhileIterable = TakeWhileIterable$();
   let _isFinished = dart.JsSymbol('_isFinished');
   let TakeWhileIterator$ = dart.generic(function(E) {
     class TakeWhileIterator extends core.Iterator$(E) {
       TakeWhileIterator(iterator$, f$) {
         this[_iterator] = iterator$;
@@ skipping 90 matching lines @@
   });
   let SkipIterator = SkipIterator$();
   let SkipWhileIterable$ = dart.generic(function(E) {
     class SkipWhileIterable extends collection.IterableBase$(E) {
       SkipWhileIterable(iterable$, f$) {
         this[_iterable] = iterable$;
         this[_f] = f$;
         super.IterableBase();
       }
       get iterator() {
-        return new (SkipWhileIterator$(E))(this[_iterable].iterator, dart.closureWrap(this[_f], "(E) → bool"));
+        return new (SkipWhileIterator$(E))(this[_iterable].iterator, dart.as(this[_f], dart.throw_("Unimplemented type (E) → bool")));
       }
     }
     return SkipWhileIterable;
   });
   let SkipWhileIterable = SkipWhileIterable$();
   let _hasSkipped = dart.JsSymbol('_hasSkipped');
   let SkipWhileIterator$ = dart.generic(function(E) {
     class SkipWhileIterator extends core.Iterator$(E) {
       SkipWhileIterator(iterator$, f$) {
         this[_iterator] = iterator$;
@@ skipping 314 matching lines @@
         } else {
           buffer.write(list.get(0));
           for (let i = 1; dart.notNull(i) < dart.notNull(list.length); i = dart.notNull(i) + 1) {
             buffer.write(separator);
             buffer.write(list.get(i));
           }
         }
         return buffer.toString();
       }
       where(iterable, f) {
-        return new (WhereIterable$(T))(dart.as(iterable, core.Iterable$(T)), dart.closureWrap(f, "(T) → bool"));
+        return new (WhereIterable$(T))(dart.as(iterable, core.Iterable$(T)), dart.as(f, dart.throw_("Unimplemented type (T) → bool")));
       }
       static map(iterable, f) {
         return new MappedIterable(iterable, f);
       }
       static mapList(list, f) {
         return new MappedListIterable(list, f);
       }
       static expand(iterable, f) {
         return new ExpandIterable(iterable, f);
       }
       takeList(list, n) {
         return new (SubListIterable$(T))(dart.as(list, core.Iterable$(T)), 0, n);
       }
       takeWhile(iterable, test) {
-        return new (TakeWhileIterable$(T))(dart.as(iterable, core.Iterable$(T)), dart.closureWrap(test, "(T) → bool"));
+        return new (TakeWhileIterable$(T))(dart.as(iterable, core.Iterable$(T)), dart.as(test, dart.throw_("Unimplemented type (T) → bool")));
       }
       skipList(list, n) {
         return new (SubListIterable$(T))(dart.as(list, core.Iterable$(T)), n, null);
       }
       skipWhile(iterable, test) {
-        return new (SkipWhileIterable$(T))(dart.as(iterable, core.Iterable$(T)), dart.closureWrap(test, "(T) → bool"));
+        return new (SkipWhileIterable$(T))(dart.as(iterable, core.Iterable$(T)), dart.as(test, dart.throw_("Unimplemented type (T) → bool")));
       }
       reversedList(list) {
         return new (ReversedListIterable$(T))(dart.as(list, core.Iterable$(T)));
       }
       static sortList(list, compare) {
         if (compare == null)
           compare = core.Comparable.compare;
         Sort.sort(list, compare);
       }
       static shuffleList(list, random) {
@@ skipping 814 matching lines @@
   exports.ReversedListIterable = ReversedListIterable;
   exports.UnmodifiableListError = UnmodifiableListError;
   exports.NonGrowableListError = NonGrowableListError;
   exports.makeListFixedLength = makeListFixedLength;
   exports.Lists = Lists;
   exports.printToConsole = printToConsole;
   exports.Sort = Sort;
   exports.Symbol = Symbol;
   exports.POWERS_OF_TEN = POWERS_OF_TEN;
 })(_internal || (_internal = {}));