diff --git a/hphp/doc/ir.specification b/hphp/doc/ir.specification
index b60deb0ef..ce153b850 100644
--- a/hphp/doc/ir.specification
+++ b/hphp/doc/ir.specification
@@ -1616,9 +1616,15 @@ IterFree<IterId> S0:FramePtr
   Free the iterator variable whose index is given by S1 in the stack
   frame pointed to by S0.
 
+D:Bool = DecodeCufIter<IterId> S0:{Arr|Obj|Str} S1:FramePtr
+
+  Decode S0 as a callable, and write the decoded values to the iterator
+  specified by IterId. Returns true iff it successfully decoded the
+  callable. Does not raise warnings, or throw exceptions.
+
 CIterFree<IterId> S0:FramePtr
 
-  Free the iterator variable whose index is given by S1 in the stack
+  Free the iterator variable whose index is given by IterId in the stack
   frame pointed to by S0.
 
 
diff --git a/hphp/runtime/vm/as.cpp b/hphp/runtime/vm/as.cpp
index 3eb36a884..4c9ced843 100644
--- a/hphp/runtime/vm/as.cpp
+++ b/hphp/runtime/vm/as.cpp
@@ -1160,7 +1160,7 @@ void parse_numiters(AsmState& as) {
 void parse_function_body(AsmState&, int nestLevel = 0);
 
 /*
- * directive-fault : identifier '{' function-body
+ * directive-fault : identifier integer? '{' function-body
  *                 ;
  */
 void parse_fault(AsmState& as, int nestLevel) {
@@ -1170,6 +1170,11 @@ void parse_fault(AsmState& as, int nestLevel) {
   if (!as.in.readword(label)) {
     as.error("expected label name after .try_fault");
   }
+  int iterId = -1;
+  as.in.skipWhitespace();
+  if (as.in.peek() != '{') {
+    iterId = read_opcode_arg<int32_t>(as);
+  }
   as.in.expectWs('{');
   parse_function_body(as, nestLevel + 1);
 
@@ -1177,7 +1182,7 @@ void parse_fault(AsmState& as, int nestLevel) {
   eh.m_ehtype = EHEnt::EHType_Fault;
   eh.m_base = start;
   eh.m_past = as.ue->bcPos();
-  eh.m_iterId = -1; // only used for debug printing
+  eh.m_iterId = iterId;
 
   as.addLabelEHFault(label, as.fe->ehtab().size() - 1);
 }
diff --git a/hphp/runtime/vm/bytecode.cpp b/hphp/runtime/vm/bytecode.cpp
index 7def15076..d2145a66d 100644
--- a/hphp/runtime/vm/bytecode.cpp
+++ b/hphp/runtime/vm/bytecode.cpp
@@ -5903,6 +5903,7 @@ inline void OPTBLD_INLINE VMExecutionContext::iopFPushCtorD(PC& pc) {
 inline void OPTBLD_INLINE VMExecutionContext::iopDecodeCufIter(PC& pc) {
   NEXT();
   DECODE_IA(itId);
+  DECODE(Offset, offset);
 
   Iter* it = frame_iter(m_fp, itId);
   CufIter &cit = it->cuf();
@@ -5919,26 +5920,21 @@ inline void OPTBLD_INLINE VMExecutionContext::iopDecodeCufIter(PC& pc) {
   const Func* f = vm_decode_function(tvAsVariant(func),
                                      ar, false,
                                      obj, cls, invName,
-                                     true);
+                                     false);
 
-  bool ret = true;
   if (f == nullptr) {
-    f = SystemLib::s_nullFunc;
-    obj = nullptr;
-    cls = nullptr;
-    invName = nullptr;
-    ret = false;
-  }
-
-  cit.setFunc(f);
-  if (obj) {
-    cit.setCtx(obj);
-    obj->incRefCount();
+    pc += offset;
   } else {
-    cit.setCtx(cls);
+    cit.setFunc(f);
+    if (obj) {
+      cit.setCtx(obj);
+      obj->incRefCount();
+    } else {
+      cit.setCtx(cls);
+    }
+    cit.setName(invName);
   }
-  cit.setName(invName);
-  tvAsVariant(m_stack.top()) = ret;
+  m_stack.popC();
 }
 
 inline void OPTBLD_INLINE VMExecutionContext::iopFPushCufIter(PC& pc) {
diff --git a/hphp/runtime/vm/func.cpp b/hphp/runtime/vm/func.cpp
index d2c84a91b..a4467a185 100644
--- a/hphp/runtime/vm/func.cpp
+++ b/hphp/runtime/vm/func.cpp
@@ -479,8 +479,9 @@ void Func::prettyPrint(std::ostream& out) const {
     if (params[i].funcletOff() != InvalidAbsoluteOffset) {
       out << " DV for parameter " << i << " at " << params[i].funcletOff();
       if (params[i].phpCode()) {
-        out << " = " << params[i].phpCode()->data() << std::endl;
+        out << " = " << params[i].phpCode()->data();
       }
+      out << std::endl;
     }
   }
   const EHEntVec& ehtab = shared()->m_ehtab;
diff --git a/hphp/runtime/vm/hhbc.h b/hphp/runtime/vm/hhbc.h
index 61956c993..23dae657f 100644
--- a/hphp/runtime/vm/hhbc.h
+++ b/hphp/runtime/vm/hhbc.h
@@ -537,9 +537,9 @@ enum SetOpOp {
   O(IterNextK,       FOUR(IA,BA,HA,HA),NOV,             NOV,        CF) \
   O(MIterNextK,      FOUR(IA,BA,HA,HA),NOV,             NOV,        CF) \
   O(WIterNextK,      FOUR(IA,BA,HA,HA),NOV,             NOV,        CF) \
+  O(DecodeCufIter,   TWO(IA,BA),       ONE(CV),         NOV,        CF) \
   O(IterFree,        ONE(IA),          NOV,             NOV,        NF) \
   O(MIterFree,       ONE(IA),          NOV,             NOV,        NF) \
-  O(DecodeCufIter,   ONE(IA),          ONE(CV),         ONE(CV),    NF) \
   O(CIterFree,       ONE(IA),          NOV,             NOV,        NF) \
   O(Incl,            NA,               ONE(CV),         ONE(CV),    CF) \
   O(InclOnce,        NA,               ONE(CV),         ONE(CV),    CF) \
diff --git a/hphp/runtime/vm/jit/codegen.cpp b/hphp/runtime/vm/jit/codegen.cpp
index 64cca0ba3..c56661d15 100644
--- a/hphp/runtime/vm/jit/codegen.cpp
+++ b/hphp/runtime/vm/jit/codegen.cpp
@@ -5269,6 +5269,13 @@ void CodeGenerator::cgIterFree(IRInstruction* inst) {
                ArgGroup(m_regs).addr(fpReg, offset));
 }
 
+void CodeGenerator::cgDecodeCufIter(IRInstruction* inst) {
+  PhysReg fpReg = m_regs[inst->src(1)].reg();
+  int64_t offset = iterOffset(inst->extra<DecodeCufIter>()->iterId);
+  cgCallHelper(m_as, (TCA)decodeCufIterHelper, inst->dst(), kSyncPoint,
+               ArgGroup(m_regs).addr(fpReg, offset).typedValue(inst->src(0)));
+}
+
 void CodeGenerator::cgCIterFree(IRInstruction* inst) {
   PhysReg fpReg = m_regs[inst->src(0)].reg();
   int64_t  offset = iterOffset(inst->extra<CIterFree>()->iterId);
diff --git a/hphp/runtime/vm/jit/extradata.h b/hphp/runtime/vm/jit/extradata.h
index b9d1aac39..c9b9c73d9 100644
--- a/hphp/runtime/vm/jit/extradata.h
+++ b/hphp/runtime/vm/jit/extradata.h
@@ -312,6 +312,7 @@ X(StLoc,                        LocalId);
 X(StLocNT,                      LocalId);
 X(IterFree,                     IterId);
 X(CIterFree,                    IterId);
+X(DecodeCufIter,                IterId);
 X(CufIterSpillFrame,            FPushCufData);
 X(DefConst,                     ConstData);
 X(LdConst,                      ConstData);
diff --git a/hphp/runtime/vm/jit/hhbctranslator.cpp b/hphp/runtime/vm/jit/hhbctranslator.cpp
index 155247f94..37031cf7e 100644
--- a/hphp/runtime/vm/jit/hhbctranslator.cpp
+++ b/hphp/runtime/vm/jit/hhbctranslator.cpp
@@ -963,6 +963,20 @@ void HhbcTranslator::emitIterFree(uint32_t iterId) {
   gen(IterFree, IterId(iterId), m_tb->getFp());
 }
 
+void HhbcTranslator::emitDecodeCufIter(uint32_t iterId, int offset) {
+  SSATmp* src = popC();
+  Type type = src->type();
+  if (type.subtypeOfAny(Type::Arr, Type::Str, Type::Obj)) {
+    SSATmp* res = gen(DecodeCufIter, Type::Bool,
+                      IterId(iterId), src, m_tb->getFp());
+    gen(DecRef, src);
+    emitJmpCondHelper(offset, true, res);
+  } else {
+    gen(DecRef, src);
+    emitJmp(offset, true, false);
+  }
+}
+
 void HhbcTranslator::emitCIterFree(uint32_t iterId) {
   gen(CIterFree, IterId(iterId), m_tb->getFp());
 }
diff --git a/hphp/runtime/vm/jit/hhbctranslator.h b/hphp/runtime/vm/jit/hhbctranslator.h
index bc95bec11..606e2b02d 100644
--- a/hphp/runtime/vm/jit/hhbctranslator.h
+++ b/hphp/runtime/vm/jit/hhbctranslator.h
@@ -353,6 +353,7 @@ struct HhbcTranslator {
                       uint32_t keyLocalId);
 
   void emitIterFree(uint32_t iterId);
+  void emitDecodeCufIter(uint32_t iterId, int targetOffset);
   void emitCIterFree(uint32_t iterId);
   void emitVerifyParamType(uint32_t paramId);
 
diff --git a/hphp/runtime/vm/jit/ir.h b/hphp/runtime/vm/jit/ir.h
index b49657f75..1d052bb39 100644
--- a/hphp/runtime/vm/jit/ir.h
+++ b/hphp/runtime/vm/jit/ir.h
@@ -481,6 +481,8 @@ O(WIterNext,                   D(Bool), S(FramePtr)                           \
 O(WIterNextK,                  D(Bool), S(FramePtr)                           \
                                           C(Int) C(Int) C(Int), E|N|Mem|Refs) \
 O(IterFree,                         ND, S(FramePtr),            E|N|Mem|Refs) \
+O(DecodeCufIter,               D(Bool), S(Arr,Obj,Str)                        \
+                                          S(FramePtr),          E|N|Mem|Refs) \
 O(CIterFree,                        ND, S(FramePtr),            E|N|Mem|Refs) \
 O(DefMIStateBase,         D(PtrToCell), NA,                               NF) \
 O(BaseG,                   D(PtrToGen), C(TCA)                                \
diff --git a/hphp/runtime/vm/jit/irtranslator.cpp b/hphp/runtime/vm/jit/irtranslator.cpp
index 0cb34aa5a..80a3e12f9 100644
--- a/hphp/runtime/vm/jit/irtranslator.cpp
+++ b/hphp/runtime/vm/jit/irtranslator.cpp
@@ -1461,6 +1461,13 @@ TranslatorX64::irTranslateIterFree(const Tracelet& t,
   HHIR_EMIT(IterFree, i.imm[0].u_IVA);
 }
 
+void
+TranslatorX64::irTranslateDecodeCufIter(const Tracelet& t,
+                                        const NormalizedInstruction& i) {
+
+  HHIR_EMIT(DecodeCufIter, i.imm[0].u_IVA, i.offset() + i.imm[1].u_BA);
+}
+
 void
 TranslatorX64::irTranslateCIterFree(const Tracelet& t,
                                     const NormalizedInstruction& i) {
diff --git a/hphp/runtime/vm/jit/translator-x64-helpers.cpp b/hphp/runtime/vm/jit/translator-x64-helpers.cpp
index 5481c8df5..54118b3c4 100644
--- a/hphp/runtime/vm/jit/translator-x64-helpers.cpp
+++ b/hphp/runtime/vm/jit/translator-x64-helpers.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/vm/jit/targetcache.h"
 #include "hphp/runtime/eval/runtime/file_repository.h"
 #include "hphp/runtime/vm/event_hook.h"
+#include "hphp/runtime/base/builtin_functions.h"
 #include "hphp/runtime/base/stats.h"
 
 namespace HPHP {
@@ -269,4 +270,33 @@ void functionEnterHelper(const ActRec* ar) {
   sp = g_vmContext->m_stack.top();
 }
 
+HOT_FUNC_VM
+int64_t decodeCufIterHelper(Iter* it, TypedValue func) {
+  DECLARE_FRAME_POINTER(framePtr);
+
+  ObjectData* obj = nullptr;
+  HPHP::Class* cls = nullptr;
+  StringData* invName = nullptr;
+
+  auto ar = (ActRec*)framePtr->m_savedRbp;
+  if (LIKELY(ar->m_func->isBuiltin())) {
+    ar = g_vmContext->getOuterVMFrame(ar);
+  }
+  const Func* f = vm_decode_function(tvAsVariant(&func),
+                                     ar, false,
+                                     obj, cls, invName,
+                                     false);
+  if (UNLIKELY(!f)) return false;
+  CufIter &cit = it->cuf();
+  cit.setFunc(f);
+  if (obj) {
+    cit.setCtx(obj);
+    obj->incRefCount();
+  } else {
+    cit.setCtx(cls);
+  }
+  cit.setName(invName);
+  return true;
+}
+
 } } // HPHP::Transl
diff --git a/hphp/runtime/vm/jit/translator-x64.h b/hphp/runtime/vm/jit/translator-x64.h
index e43a2ccae..9f1f3ff03 100644
--- a/hphp/runtime/vm/jit/translator-x64.h
+++ b/hphp/runtime/vm/jit/translator-x64.h
@@ -445,6 +445,7 @@ private:
   CASE(IterFree) \
   CASE(FPassV) \
   CASE(UnsetN) \
+  CASE(DecodeCufIter) \
 
   // These are instruction-like functions which cover more than one
   // opcode.
@@ -828,6 +829,7 @@ const size_t kMaxNumTrampolines = kTrampolinesBlockSize /
 void fcallHelperThunk() asm ("__fcallHelperThunk");
 void funcBodyHelperThunk() asm ("__funcBodyHelperThunk");
 void functionEnterHelper(const ActRec* ar);
+int64_t decodeCufIterHelper(Iter* it, TypedValue func);
 
 // These could be static but are used in hopt/codegen.cpp
 void raiseUndefVariable(StringData* nm);
diff --git a/hphp/runtime/vm/jit/translator.cpp b/hphp/runtime/vm/jit/translator.cpp
index bd7b75a25..11783c7c2 100644
--- a/hphp/runtime/vm/jit/translator.cpp
+++ b/hphp/runtime/vm/jit/translator.cpp
@@ -1333,7 +1333,7 @@ static const struct {
                                       Stack1,       OutArray,         -2 }},
   { OpCufSafeReturn,{StackTop3|DontGuardAny,
                                       Stack1,       OutUnknown,       -2 }},
-  { OpDecodeCufIter,{Stack1,          Stack1,       OutBoolean,        0 }},
+  { OpDecodeCufIter,{Stack1,          None,         OutNone,          -1 }},
 
   /*** 11. Iterator instructions ***/
 
diff --git a/hphp/runtime/vm/jit/translator.h b/hphp/runtime/vm/jit/translator.h
index 96181eeda..638036052 100644
--- a/hphp/runtime/vm/jit/translator.h
+++ b/hphp/runtime/vm/jit/translator.h
@@ -1021,6 +1021,7 @@ opcodeControlFlowInfo(const Opcode instr) {
     case OpMIterInitK: // Ditto
     case OpWIterInit: // Ditto
     case OpWIterInitK: // Ditto
+    case OpDecodeCufIter: // Ditto
     case OpThrow:
     case OpUnwind:
     case OpEval:
diff --git a/hphp/runtime/vm/verifier/check_func.cpp b/hphp/runtime/vm/verifier/check_func.cpp
index f34ebfd81..e7580f11c 100644
--- a/hphp/runtime/vm/verifier/check_func.cpp
+++ b/hphp/runtime/vm/verifier/check_func.cpp
@@ -730,9 +730,6 @@ bool FuncChecker::checkIter(State* cur, PC pc) {
         "IterInit* or MIterInit* <%d> trying to double-initialize\n", id);
       ok = false;
     }
-    if (Op(*pc) == OpDecodeCufIter) {
-      cur->iters[id] = true;
-    }
   } else {
     if (!cur->iters[id]) {
       verify_error("Cannot access un-initialized iter %d\n", id);
diff --git a/hphp/test/slow/builtin_support/setwithref.php b/hphp/test/slow/builtin_support/setwithref.php
index 3033b9447..b811ea032 100644
--- a/hphp/test/slow/builtin_support/setwithref.php
+++ b/hphp/test/slow/builtin_support/setwithref.php
@@ -3,6 +3,7 @@
 require_once "support.hhas";
 
 class X {
+  private $p = true;
   function __destruct() { var_dump(__METHOD__); }
   static function s_test($x) { return $x !== true; }
   function o_test($x) { return $x === $this->p; }
@@ -25,12 +26,12 @@ function test() {
   $a = array(1, 'foo' => 'bar', 0, true, false);
   $b =& $a['foo'];
 
-  var_dump(fast_array_filter($a, null));
-  var_dump(fast_array_filter($a, function($a) { return !$a; }));
-  var_dump(fast_array_filter($a, array('X', 's_test')));
-  var_dump(fast_array_filter($a, array(new X, 'o_test')));
-  var_dump(fast_array_filter($a, array(new X, 'bar')));
-  var_dump(fast_array_filter($a, 'filt'));
+  var_dump("No function", fast_array_filter($a, null));
+  var_dump("Closure", fast_array_filter($a, function($a) { return !$a; }));
+  var_dump("Static Method", fast_array_filter($a, array('X', 's_test')));
+  var_dump("Dynamic Method", fast_array_filter($a, array(new X, 'o_test')));
+  var_dump("__call", fast_array_filter($a, array(new X, 'bar')));
+  var_dump("string", fast_array_filter($a, 'filt'));
 
   var_dump(fast_array_map(function($a) { return $a.$a; }, $a));
   var_dump(fast_array_map(function&(&$a) { return $a; }, $a));
diff --git a/hphp/test/slow/builtin_support/setwithref.php.expect b/hphp/test/slow/builtin_support/setwithref.php.expect
index bcfcdbcb1..8718996db 100644
--- a/hphp/test/slow/builtin_support/setwithref.php.expect
+++ b/hphp/test/slow/builtin_support/setwithref.php.expect
@@ -1,6 +1,8 @@
 array(1) {
   ["foo"]=>
-  object(X)#1 (0) {
+  object(X)#1 (1) {
+    ["p":"X":private]=>
+    bool(true)
   }
 }
 string(13) "X::__destruct"
@@ -12,6 +14,7 @@ array(1) {
   [0]=>
   &string(3) "bar"
 }
+string(11) "No function"
 array(3) {
   [0]=>
   int(1)
@@ -20,12 +23,14 @@ array(3) {
   [2]=>
   bool(true)
 }
+string(7) "Closure"
 array(2) {
   [1]=>
   int(0)
   [3]=>
   bool(false)
 }
+string(13) "Static Method"
 array(4) {
   [0]=>
   int(1)
@@ -37,9 +42,13 @@ array(4) {
   bool(false)
 }
 string(13) "X::__destruct"
-array(0) {
+string(14) "Dynamic Method"
+array(1) {
+  [2]=>
+  bool(true)
 }
 string(13) "X::__destruct"
+string(6) "__call"
 array(3) {
   ["foo"]=>
   &string(3) "bar"
@@ -48,6 +57,7 @@ array(3) {
   [2]=>
   bool(true)
 }
+string(6) "string"
 array(1) {
   [2]=>
   bool(true)
diff --git a/hphp/test/slow/builtin_support/support.hhas b/hphp/test/slow/builtin_support/support.hhas
index 7198e3615..97311a888 100644
--- a/hphp/test/slow/builtin_support/support.hhas
+++ b/hphp/test/slow/builtin_support/support.hhas
@@ -23,39 +23,59 @@
           RetC
 }
 
-.function fast_array_filter($arr, $func) {
+.function fast_array_filter($arr = no_args, $func = no_func, $res = entry) {
           .numiters 2;
 
-          NewArray
-          SetL $res
-          PopC
+# if we get here, a value was supplied for $res
+          String "array_filter() expects at most 2 parameters"
+          Jmp warning
+no_args:  String "array_filter() expects at least 1 parameter, 0 given"
+          Jmp warning
+not_array:String "array_filter() expects parameter 1 to be array"
+          Jmp warning
+bad_func: String "array_filter() expects parameter 2 to be a valid callback"
+          Jmp warning
+warning:  Cns "E_USER_WARNING"
+          FCallBuiltin 2 2 "trigger_error"
+          PopR
+          Null
+          RetC
+
+entry:    IsArrayL $arr
+          JmpZ not_array
 
           IssetL $func
-          JmpZ null_func
+          JmpZ no_func
 
           CGetL $func
-          DecodeCufIter 0
-          JmpZ bad_func
+          DecodeCufIter 0 bad_func
 .try_fault kill_iter_0 {
-          CGetL $arr
-          WIterInitK 1 endloop_a $v $k
-.try_fault kill_iter_1 {
-loop_a:   FPushCufIter 1 0
-          FPassL 0 $v
-          FCall 1
-          UnboxR
-          JmpZ skip_a
-          SetWithRefLM <L:$res EL:$k> $v
-skip_a:   WIterNextK 1 loop_a $v $k
-}
+            NewArray
+            SetL $res
+            PopC
+
+            CGetL $arr
+            WIterInitK 1 endloop_a $v $k
+  .try_fault kill_iter_1 1 {
+    loop_a:   FPushCufIter 1 0
+              FPassL 0 $v
+              FCall 1
+              UnboxR
+              JmpZ skip_a
+              SetWithRefLM <L:$res EL:$k> $v
+    skip_a:   WIterNextK 1 loop_a $v $k
+  }
 }
 endloop_a:CIterFree 0
 endloop_n:CGetL $res
           RetC
 
-null_func:CGetL $arr
+no_func:  NewArray
+          SetL $res
+          PopC
+          CGetL $arr
           WIterInitK 1 endloop_n $v $k
-.try_fault kill_iter_1 {
+.try_fault kill_iter_1_only 1 {
 loop_n:   CGetL $v
           JmpZ skip_n
           SetWithRefLM <L:$res EL:$k> $v
@@ -63,55 +83,87 @@ skip_n:   WIterNextK 1 loop_n $v $k
 }
           Jmp endloop_n
 
-bad_func: Null
-          RetC
-
 kill_iter_0:
           CIterFree 0
           Unwind
 kill_iter_1:
-          IterFree 0
+          IterFree 1
+          Unwind
+kill_iter_1_only:
+          IterFree 1
           Unwind
 }
 
-.function fast_array_map($func, $arr) {
+.function fast_array_map($func = no_args, $arr = one_arg, $res = one_array) {
           .numiters 2;
 
-          IssetL $func
+# If we get here, a value was supplied for $res
+# so we bail out to the c++ implementation
+          FPushFuncD   1   "__builtin_array_map"
+          FCallBuiltin 0 0 "func_get_args"
+          UnboxR
+          FPassC       0
+          FCallArray
+          UnboxR
+          RetC
+
+no_args:  String "array_map() expects at least 2 parameters, 0 given"
+          Jmp warning
+
+one_arg:  String "array_map() expects at least 2 parameters, 1 given"
+          Jmp warning
+
+not_array_citer_free:
+          CIterFree 0
+not_array:String "array_map() expects parameter 2 to be array"
+          Jmp warning
+bad_func: String "array_map() expects parameter 1 to be a valid callback"
+          Jmp warning
+warning:  Cns "E_USER_WARNING"
+          FCallBuiltin 2 2 "trigger_error"
+          PopR
+          Null
+          RetC
+
+# but if we get here, there was only one array,
+# so we use the fast, php version
+
+one_array:IssetL $func
           JmpZ ident
           CGetL $func
-          DecodeCufIter 0
-          JmpZ bad_func
-
+          DecodeCufIter 0 bad_func
 .try_fault kill_iter_0 {
-          NewArray
-          SetL $res
-          PopC
+            IsArrayL $arr
+            JmpZ not_array_citer_free
 
-          CGetL $arr
-          WIterInitK 1 endloop $v $k
+            NewArray
+            SetL $res
+            PopC
 
-.try_fault kill_iter_1 {
-loop_x:   FPushCufIter 1 0
-          FPassL 0 $v
-          FCall 1
-          SetWithRefRM <L:$res EL:$k>
-          WIterNextK 1 loop_x $v $k
-}
+            CGetL $arr
+            WIterInitK 1 endloop $v $k
+
+  .try_fault kill_iter_1 1 {
+    loop_x:   FPushCufIter 1 0
+              FPassL 0 $v
+              FCall 1
+              SetWithRefRM <L:$res EL:$k>
+              WIterNextK 1 loop_x $v $k
+  }
 }
 endloop:  CIterFree 0
           CGetL $res
           RetC
 
-ident:    CGetL $arr
+ident:    IsArrayL $arr
+          JmpZ not_array
+          CGetL $arr
           RetC
 
-bad_func: Null
-          RetC
 kill_iter_0:
           CIterFree 0
           Unwind
 kill_iter_1:
-          IterFree 0
+          IterFree 1
           Unwind
 }