From d6062f7c450c2cde5aa37e1a9a883ffe90622941 Mon Sep 17 00:00:00 2001
From: Robert Stone <talby@trap.mtview.ca.us>
Date: Sat, 21 Oct 2017 12:15:08 -0700
Subject: [PATCH] [Perl] emulate Python zip() for Perl (#8192)

* [Perl] emulate Python zip() for Perl

* [Perl] retool zip() uses away from the callback form
---
 .../AI-MXNet/lib/AI/MXNet/AutoGrad.pm         |   8 +-
 perl-package/AI-MXNet/lib/AI/MXNet/Base.pm    |  23 ++--
 .../AI-MXNet/lib/AI/MXNet/Executor/Group.pm   |  74 ++++++------
 .../AI-MXNet/lib/AI/MXNet/Gluon/Block.pm      |  24 ++--
 .../AI-MXNet/lib/AI/MXNet/Gluon/Parameter.pm  |   8 +-
 .../AI-MXNet/lib/AI/MXNet/Gluon/RNN/Cell.pm   |  14 +--
 .../AI-MXNet/lib/AI/MXNet/Gluon/RNN/Layer.pm  |   6 +-
 .../AI-MXNet/lib/AI/MXNet/Gluon/Trainer.pm    |   8 +-
 .../AI-MXNet/lib/AI/MXNet/Gluon/Utils.pm      |   8 +-
 perl-package/AI-MXNet/lib/AI/MXNet/KVStore.pm |   6 +-
 perl-package/AI-MXNet/lib/AI/MXNet/Metric.pm  |  66 +++++------
 perl-package/AI-MXNet/lib/AI/MXNet/Module.pm  |  12 +-
 perl-package/AI-MXNet/lib/AI/MXNet/Monitor.pm |  12 +-
 perl-package/AI-MXNet/lib/AI/MXNet/NDArray.pm |  12 +-
 .../AI-MXNet/lib/AI/MXNet/NDArray/Slice.pm    |  20 ++--
 .../AI-MXNet/lib/AI/MXNet/RNN/Cell.pm         |  18 +--
 perl-package/AI-MXNet/lib/AI/MXNet/Symbol.pm  |   6 +-
 perl-package/AI-MXNet/t/test_autograd.t       |   6 +-
 perl-package/AI-MXNet/t/test_base.t           | 107 ++++++++++++++++++
 perl-package/AI-MXNet/t/test_model_parallel.t |   6 +-
 perl-package/AI-MXNet/t/test_module.t         |   8 +-
 .../AI-MXNet/t/test_multi_device_exec.t       |   6 +-
 perl-package/AI-MXNetCAPI/mxnet.i             |  37 ++++++
 23 files changed, 318 insertions(+), 177 deletions(-)
 create mode 100644 perl-package/AI-MXNet/t/test_base.t

diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/AutoGrad.pm b/perl-package/AI-MXNet/lib/AI/MXNet/AutoGrad.pm
index b49c0b69c52f..221840e300aa 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/AutoGrad.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/AutoGrad.pm
@@ -333,10 +333,10 @@ method grad(
     );
 
     my @ret;
-    zip(sub {
-        my ($handle, $stype) = @_;
+    for(zip($grad_vars, $grad_stypes)) {
+        my ($handle, $stype) = @$_;
         push @ret, AI::MXNet::NDArray->new(handle => $handle, stype => $stype);
-    }, $grad_vars, $grad_stypes);
+    }
     if(blessed $variables)
     {
         return $ret[0];
@@ -474,4 +474,4 @@ func _parse_head($heads, $head_grads)
     return (\@head_handles, \@hgrad_handles);
 }
 
-1;
\ No newline at end of file
+1;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Base.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Base.pm
index a8da8470f574..f748ecbe1f37 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Base.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Base.pm
@@ -120,12 +120,17 @@ use constant GRAD_REQ_MAP => {
 
 sub zip
 {
-    my ($sub, @arrays) = @_;
-    my $len = @{ $arrays[0] };
-    for (my $i = 0; $i < $len; $i++)
+    if('CODE' eq ref $_[0])
     {
-        $sub->(map { $_->[$i] } @arrays);
+        # continue supporting the callback style
+        my $code = shift;
+        $code->(@$_) for AI::MXNetCAPI::py_zip(map { \@$_ } @_);
+        return;
     }
+    # the map() here may seem like a no-op, but triggers overloading or
+    # whatever else is needed to make array-ish things actually arrays
+    # before entering the low level list builder.
+    return AI::MXNetCAPI::py_zip(map { \@$_ } @_);
 }
 
 =head2 enumerate
@@ -270,16 +275,14 @@ sub build_param_doc
     $remove_dup //= 1;
     my %param_keys;
     my @param_str;
-    zip(sub {
-            my ($key, $type_info, $desc) = @_;
-            return if exists $param_keys{$key} and $remove_dup;
+    for(zip($arg_names, $arg_types, $arg_descs)) {
+            my ($key, $type_info, $desc) = @$_;
+            next if exists $param_keys{$key} and $remove_dup;
             $param_keys{$key} = 1;
             my $ret = sprintf("%s : %s", $key, $type_info);
             $ret .= "\n    ".$desc if length($desc);
             push @param_str,  $ret;
-        },
-        $arg_names, $arg_types, $arg_descs
-    );
+    }
     return sprintf("Parameters\n----------\n%s\n", join("\n", @param_str));
 }
 
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Executor/Group.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Executor/Group.pm
index 7ac054333c13..acacffde1ee2 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Executor/Group.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Executor/Group.pm
@@ -57,18 +57,18 @@ func _split_input_slice($batch_size, $work_load_list)
 # Load a array ref of arrays into a array ref of arrays specified by slices
 func _load_general($data, $targets, $major_axis)
 {
-    zip(sub {
-        my ($d_src, $d_targets, $axis) = @_;
+    for(zip($data, $targets, $major_axis)) {
+        my ($d_src, $d_targets, $axis) = @$_;
         if(blessed($d_targets) and $d_targets->isa('AI::MXNet::NDarray'))
         {
             $d_src->copyto($d_targets);
         }
         elsif(ref $d_targets eq 'ARRAY' and blessed $d_targets->[0])
         {
-            zip(sub {
-                my ($src, $dst) = @_;
+            for(zip($d_src, $d_targets)) {
+                my ($src, $dst) = @$_;
                 $src->copyto($dst);
-            }, $d_src, $d_targets);
+            }
         }
         else
         {
@@ -124,7 +124,7 @@ func _load_general($data, $targets, $major_axis)
                 }
             }
         }
-    }, $data, $targets, $major_axis);
+    }
 }
 
 # Load data into sliced arrays
@@ -144,8 +144,8 @@ func _load_label($batch, $targets, $major_axis)
 func _merge_multi_context($outputs, $major_axis)
 {
     my @rets;
-    zip(sub {
-        my ($tensors, $axis) = @_;
+    for(zip($outputs, $major_axis)) {
+        my ($tensors, $axis) = @$_;
         if($axis >= 0)
         {
             if(@$tensors == 1)
@@ -165,7 +165,7 @@ func _merge_multi_context($outputs, $major_axis)
             # first one, without checking they are actually the same
             push @rets, $tensors->[0];
         }
-    }, $outputs, $major_axis);
+    }
     return \@rets;
 }
 
@@ -353,9 +353,9 @@ method decide_slices(ArrayRef[AI::MXNet::DataDesc] $data_shapes)
 {
     confess("empty data_shapes array") unless @{ $data_shapes } > 0;
     my $major_axis = [map { AI::MXNet::DataDesc->get_batch_axis($_->layout) } @{ $data_shapes }];
-    zip(sub {
-        my ($desc, $axis) = @_;
-        return if($axis == -1);
+    for(zip($data_shapes, $major_axis)) {
+        my ($desc, $axis) = @$_;
+        next if($axis == -1);
         my $batch_size = $desc->shape->[$axis];
         if(defined $self->_p->batch_size)
         {
@@ -370,7 +370,7 @@ method decide_slices(ArrayRef[AI::MXNet::DataDesc] $data_shapes)
             $self->_p->batch_size($batch_size);
             $self->_p->slices(AI::MXNet::Executor::Group::_split_input_slice($self->_p->batch_size, $self->workload));
         }
-    }, $data_shapes, $major_axis);
+    }
     return $major_axis;
 }
 
@@ -590,16 +590,16 @@ method set_params(HashRef[AI::MXNet::NDArray] $arg_params, HashRef[AI::MXNet::ND
 method get_params(HashRef[AI::MXNet::NDArray] $arg_params, HashRef[AI::MXNet::NDArray] $aux_params)
 {
     my $weight = 0;
-    zip(sub {
-        my ($name, $block) = @_;
+    for(zip($self->param_names, $self->_p->param_arrays)) {
+        my ($name, $block) = @$_;
             my $weight = sum(map { $_->copyto(AI::MXNet::Context->cpu) } @{ $block }) / @{ $block };
             $weight->astype($arg_params->{$name}->dtype)->copyto($arg_params->{$name});
-    }, $self->param_names, $self->_p->param_arrays);
-    zip(sub {
-        my ($name, $block) = @_;
+    }
+    for(zip($self->_p->aux_names, $self->_p->aux_arrays)) {
+        my ($name, $block) = @$_;
             my $weight = sum(map { $_->copyto(AI::MXNet::Context->cpu) } @{ $block }) / @{ $block };
             $weight->astype($aux_params->{$name}->dtype)->copyto($aux_params->{$name});
-    }, $self->_p->aux_names, $self->_p->aux_arrays);
+    }
 }
 
 
@@ -668,15 +668,15 @@ method get_output_shapes()
 {
     my @shapes = map { $_->shape } @{ $self->execs->[0]->outputs };
     my @concat_shapes;
-    zip(sub {
-        my ($key, $shape, $axis) = @_;
+    for(zip($self->symbol->list_outputs, \@shapes, $self->_p->output_layouts)) {
+        my ($key, $shape, $axis) = @$_;
         my @the_shape = @{ $shape };
         if($axis >= 0)
         {
             $the_shape[$axis] = $self->_p->batch_size;
         }
         push @concat_shapes, AI::MXNet::DataDesc->new(name => $key, shape => \@the_shape);
-    }, $self->symbol->list_outputs, \@shapes, $self->_p->output_layouts);
+    }
     return \@concat_shapes;
 }
 
@@ -765,11 +765,11 @@ method backward(Maybe[AI::MXNet::NDArray|ArrayRef[AI::MXNet::NDArray]] $out_grad
 {
     confess('re-bind with for_training=1 to run backward') unless $self->for_training;
     $out_grads //= [];
-    zip(sub {
-        my ($i, $exec, $islice) = @_;
+    for(zip([0..@{ $self->_p->execs }-1], $self->_p->execs, $self->_p->slices)) {
+        my ($i, $exec, $islice) = @$_;
         my @out_grads_slice;
-        zip(sub{
-            my ($grad, $axis) = @_;
+        for(zip($out_grads, $self->_p->output_layouts)) {
+            my ($grad, $axis) = @$_;
             if($axis >= 0)
             {
                 my $og_my_slice = $grad->slice_axis({
@@ -783,9 +783,9 @@ method backward(Maybe[AI::MXNet::NDArray|ArrayRef[AI::MXNet::NDArray]] $out_grad
             {
                 push @out_grads_slice, $grad->copyto($self->contexts->[$i]);
             }
-        }, $out_grads, $self->_p->output_layouts);
+        }
         $exec->backward(\@out_grads_slice);
-    }, [0..@{ $self->_p->execs }-1], $self->_p->execs, $self->_p->slices);
+    }
 }
 
 =head2 update_metric
@@ -802,11 +802,11 @@ method backward(Maybe[AI::MXNet::NDArray|ArrayRef[AI::MXNet::NDArray]] $out_grad
 
 method update_metric(AI::MXNet::EvalMetric $eval_metric, ArrayRef[AI::MXNet::NDArray] $labels)
 {
-    zip(sub {
-        my ($texec, $islice) = @_;
+    for(zip($self->_p->execs, $self->_p->slices)) {
+        my ($texec, $islice) = @$_;
         my @labels_slice;
-        zip(sub {
-            my ($label, $axis) = @_;
+        for(zip($labels, $self->_p->label_layouts)) {
+            my ($label, $axis) = @$_;
             if($axis == 0)
             {
                 # slicing NDArray along axis 0 can avoid copying
@@ -825,9 +825,9 @@ method update_metric(AI::MXNet::EvalMetric $eval_metric, ArrayRef[AI::MXNet::NDA
             {
                 push @labels_slice, $label;
             }
-        }, $labels, $self->_p->label_layouts);
+        }
         $eval_metric->update(\@labels_slice, $texec->outputs);
-    }, $self->_p->execs, $self->_p->slices);
+    }
 }
 
 method _bind_ith_exec(
@@ -874,8 +874,8 @@ method _bind_ith_exec(
 method _sliced_shape(ArrayRef[AI::MXNet::DataDesc] $shapes, Int $i, ArrayRef[Int] $major_axis)
 {
     my @sliced_shapes;
-    zip(sub {
-        my ($desc, $axis) = @_;
+    for(zip($shapes, $major_axis)) {
+        my ($desc, $axis) = @$_;
         my @shape = @{ $desc->shape };
         if($axis >= 0)
         {
@@ -887,7 +887,7 @@ method _sliced_shape(ArrayRef[AI::MXNet::DataDesc] $shapes, Int $i, ArrayRef[Int
             dtype   => $desc->dtype,
             layout  => $desc->layout
         );
-    }, $shapes, $major_axis);
+    }
     return \@sliced_shapes;
 }
 
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Block.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Block.pm
index 982822be5dc8..148df0471f2a 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Block.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Block.pm
@@ -565,21 +565,21 @@ method infer_shape(@args)
     my $args = \@args;
     ($args) = __PACKAGE__->_flatten($args);
     my %in;
-    zip(sub {
-        my ($i, $j) = @_;
+    for(zip($inputs, $args)) {
+        my ($i, $j) = @$_;
         $in{ $i->name } = $j->shape;
-    }, $inputs, $args);
+    }
     my ($arg_shapes, undef, $aux_shapes) = $out->infer_shape(%in);
     my %sdict;
-    zip(sub {
-        my ($i, $j) = @_;
+    for(zip($out->list_arguments(), $arg_shapes)) {
+        my ($i, $j) = @$_;
         $sdict{ $i } = $j;
-    }, $out->list_arguments(), $arg_shapes);
+    }
     my %aux;
-    zip(sub {
-        my ($i, $j) = @_;
+    for(zip($out->list_auxiliary_states(), $aux_shapes)) {
+        my ($i, $j) = @$_;
         $aux{ $i } = $j;
-    }, $out->list_auxiliary_states(), $aux_shapes);
+    }
     %sdict = (%sdict, %aux);
     for my $i ($self->collect_params->values)
     {
@@ -878,10 +878,10 @@ method forward($x, @args)
     assert((Data::Dumper::Dumper($in_fmt) eq Data::Dumper::Dumper($self->_in_format)), "Invalid input format");
     my $ret = $self->_cached_graph->[1]->deepcopy;
     my %in;
-    zip(sub {
-        my ($k, $v) = @_;
+    for(zip($self->_cached_graph->[0], $args)) {
+        my ($k, $v) = @$_;
         $in{$k->name} = $v;
-    }, $self->_cached_graph->[0], $args);
+    }
     $ret->_compose(%in);
     $ret = (__PACKAGE__->_regroup($ret, $self->_out_format))[0];
     if(ref($ret) eq 'ARRAY' and wantarray)
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Parameter.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Parameter.pm
index 0341fd7e6636..d241aa196a96 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Parameter.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Parameter.pm
@@ -194,8 +194,8 @@ method _load_init($data, $ctx)
 {
     if($self->shape)
     {
-        zip(sub {
-            my ($i, $j) = @_;
+        for(zip($self->shape, $data->shape)) {
+            my ($i, $j) = @$_;
             assert(
                 ($i == 0 or $i == $j),
                 sprintf(
@@ -204,7 +204,7 @@ method _load_init($data, $ctx)
                     $self->name, "@{$self->shape}", "@{$data->shape}"
                 )
             );
-        }, $self->shape, $data->shape);
+        }
     }
     if($self->dtype)
     {
@@ -923,4 +923,4 @@ method load(
     }
 }
 
-1;
\ No newline at end of file
+1;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Cell.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Cell.pm
index d2e7db280aaa..a3fb3c51a147 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Cell.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Cell.pm
@@ -1047,10 +1047,10 @@ method hybrid_forward(GluonClass $F, GluonInput $inputs, GluonInput $states)
     if($p_states != 0)
     {
         my @tmp;
-        zip(sub {
-            my ($new_s, $old_s) = @_;
+        for(zip($next_states, $states)) {
+            my ($new_s, $old_s) = @$_;
             push @tmp, $F->where($mask->($p_states, $new_s), $new_s, $old_s);
-        }, $next_states, $states);
+        }
         $states = \@tmp;
     }
     else
@@ -1109,10 +1109,10 @@ method unroll(Int $length, GluonInput $inputs, Maybe[GluonInput] :$begin_state=,
     else
     {
         my @tmp;
-        zip(sub {
-            my ($i, $j) = @_;
+        for(zip($outputs, $inputs)) {
+            my ($i, $j) = @$_;
             push @tmp, $F->elemwise_add($i, $j);
-        }, $outputs, $inputs);
+        }
         $outputs = \@tmp;
     }
     return ($outputs, $states);
@@ -1222,4 +1222,4 @@ method unroll(Int $length, GluonInput $inputs, Maybe[GluonInput] :$begin_state=,
 
 __PACKAGE__->register('AI::MXNet::Gluon::RNN');
 
-1;
\ No newline at end of file
+1;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Layer.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Layer.pm
index fa850e62a76a..2b6e8a5bdae4 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Layer.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/RNN/Layer.pm
@@ -230,14 +230,14 @@ method forward(GluonInput $inputs, Maybe[GluonInput] $states=)
     {
         $states = [$states];
     }
-    zip(sub {
-        my ($state, $info) = @_;
+    for(zip($states, $self->state_info($batch_size))) {
+        my ($state, $info) = @$_;
         if(Dumper($state->shape) ne Dumper($info->{shape}))
         {
             my @state_shape = @{ $state->shape };
             confess("Invalid recurrent state shape. Expecting @{$info->{shape}}, got @state_shape.");
         }
-    }, $states, $self->state_info($batch_size));
+    }
     if($self->input_size == 0)
     {
         for my $i (0..$self->dir-1)
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Trainer.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Trainer.pm
index 405c6d29aa38..63f521c5c699 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Trainer.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Trainer.pm
@@ -231,14 +231,14 @@ method step(Int $batch_size, Bool $ignore_stale_grad=0)
                 $self->_kv_store->pull($i, out => $param->list_grad, priority => -$i);
             }
         }
-        zip(sub {
-            my ($upd, $arr, $grad) = @_;
+        for(zip($self->_updaters, $param->list_data, $param->list_grad)) {
+            my ($upd, $arr, $grad) = @$_;
             if(not $ignore_stale_grad or $arr->_fresh_grad)
             {
                 $upd->($i, $grad, $arr);
                 $arr->_fresh_grad(0);
             }
-        }, $self->_updaters, $param->list_data, $param->list_grad);
+        }
     }, $self->_params);
 }
 
@@ -331,4 +331,4 @@ method load_states(Str $fname)
     }
 }
 
-1;
\ No newline at end of file
+1;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Utils.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Utils.pm
index eee3cb5a907b..6acb66237195 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Utils.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Gluon/Utils.pm
@@ -163,10 +163,10 @@ method split_and_load(
     }
     my $slices = __PACKAGE__->split_data($data, scalar(@$ctx_list), $batch_axis, $even_split);
     my @ret;
-    zip(sub {
-        my ($i, $ctx) = @_;
+    for(zip($slices, $ctx_list)) {
+        my ($i, $ctx) = @$_;
         push @ret, $i->as_in_context($ctx);
-    }, $slices, $ctx_list);
+    }
     return \@ret;
 }
 
@@ -277,4 +277,4 @@ func download(Str $url, Maybe[Str] :$path=, Bool :$overwrite=0, Maybe[Str] :$sha
     return $fname
 }
 
-1;
\ No newline at end of file
+1;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/KVStore.pm b/perl-package/AI-MXNet/lib/AI/MXNet/KVStore.pm
index 4410eb3d7a7a..84a890dcc908 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/KVStore.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/KVStore.pm
@@ -481,12 +481,12 @@ sub _key_value
         assert(not blessed($vals) and @$keys == @$vals);
         my @c_keys;
         my @c_vals;
-        zip(sub {
-            my ($key, $val) = @_;
+        for(zip($keys, $vals)) {
+            my ($key, $val) = @$_;
             my ($c_key, $c_val) = _key_value($key, $val);
             push @c_keys, @$c_key;
             push @c_vals, @$c_val;
-        }, $keys, $vals);
+        }
         return (\@c_keys, \@c_vals);
     }
 }
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Metric.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Metric.pm
index a6b440be6eb3..3b9345d8baf9 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Metric.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Metric.pm
@@ -241,8 +241,8 @@ has '+name'   => (default => 'accuracy');
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred_label) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred_label) = @$_;
         if(join(',', @{$pred_label->shape}) ne join(',', @{$label->shape}))
         {
             $pred_label = AI::MXNet::NDArray->argmax_channel($pred_label);
@@ -251,7 +251,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         my $sum = ($pred_label->aspdl->flat == $label->aspdl->flat)->sum;
         $self->sum_metric($self->sum_metric + $sum);
         $self->num_inst($self->num_inst + $pred_label->size);
-    }, $labels, $preds);
+    }
 }
 
 package AI::MXNet::TopKAccuracy;
@@ -274,8 +274,8 @@ sub BUILD
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred_label) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred_label) = @$_;
         confess('Predictions should be no more than 2 dims')
             unless @{ $pred_label->shape } <= 2;
         $pred_label = $pred_label->aspdl->qsorti;
@@ -299,7 +299,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
             }
         }
         $self->num_inst($self->num_inst + $num_samples);
-    }, $labels, $preds);
+    }
 }
 
 # Calculate the F1 score of a binary classification problem.
@@ -312,16 +312,16 @@ has '+name'   => (default => 'f1');
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred_label) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred_label) = @$_;
         AI::MXNet::Metric::check_label_shapes($label, $pred_label);
         $pred_label = $pred_label->aspdl->maximum_ind;
         $label = $label->astype('int32')->aspdl;
         confess("F1 currently only supports binary classification.")
             if $label->uniq->shape->at(0) > 2;
         my ($true_positives, $false_positives, $false_negatives) = (0,0,0);
-        zip(sub{
-            my ($y_pred, $y_true) = @_;
+        for(zip($pred_label->unpdl, $label->unpdl)) {
+            my ($y_pred, $y_true) = @$_;
             if($y_pred == 1 and $y_true == 1)
             {
                 $true_positives += 1;
@@ -334,7 +334,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
             {
                 $false_negatives += 1;
             }
-        }, $pred_label->unpdl, $label->unpdl);
+        }
         my $precision;
         my $recall;
         if($true_positives + $false_positives > 0)
@@ -364,7 +364,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         }
         $self->sum_metric($self->sum_metric + $f1_score);
         $self->num_inst($self->num_inst + 1);
-    }, $labels, $preds);
+    }
 }
 
 package AI::MXNet::Perplexity;
@@ -408,8 +408,8 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
     my ($loss, $num) = (0, 0);
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         my $label_shape = $label->shape;
         my $pred_shape  = $pred->shape;
         assert(
@@ -426,7 +426,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         }
         $loss -= $pred->maximum(1e-10)->log->sum->asscalar;
         $num  += $pred->size;
-    }, $labels, $preds);
+    }
     $self->sum_metric($self->sum_metric + $loss);
     $self->num_inst($self->num_inst + $num);
 }
@@ -450,8 +450,8 @@ has '+name'   => (default => 'mae');
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         $label = $label->aspdl;
         $pred =  $pred->aspdl;
         if($label->ndims == 1)
@@ -460,7 +460,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         }
         $self->sum_metric($self->sum_metric + ($label - $pred)->abs->avg);
         $self->num_inst($self->num_inst + 1);
-    }, $labels, $preds);
+    }
 }
 
 # Calculate Mean Squared Error loss
@@ -473,8 +473,8 @@ has '+name'   => (default => 'mse');
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         $label = $label->aspdl;
         $pred =  $pred->aspdl;
         if($label->ndims == 1)
@@ -483,7 +483,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         }
         $self->sum_metric($self->sum_metric + (($label - $pred)**2)->avg);
         $self->num_inst($self->num_inst + 1);
-    }, $labels, $preds);
+    }
 }
 
 # Calculate Root Mean Squred Error loss
@@ -496,8 +496,8 @@ has '+name'   => (default => 'rmse');
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         $label = $label->aspdl;
         $pred =  $pred->aspdl;
         if($label->ndims == 1)
@@ -506,7 +506,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         }
         $self->sum_metric($self->sum_metric + sqrt((($label - $pred)**2)->avg));
         $self->num_inst($self->num_inst + 1);
-    }, $labels, $preds);
+    }
 }
 
 # Calculate Cross Entropy loss
@@ -521,8 +521,8 @@ method python_constructor_arguments() { ['eps'] }
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         $label = $label->aspdl->flat;
         $pred =  $pred->aspdl;
         my $label_shape = $label->shape->at(0);
@@ -534,7 +534,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         my $prob = $pred->index($label);
         $self->sum_metric($self->sum_metric + (-($prob + $self->eps)->log)->sum);
         $self->num_inst($self->num_inst + $label_shape);
-    }, $labels, $preds);
+    }
 }
 
 package AI::MXNet::PearsonCorrelation;
@@ -570,8 +570,8 @@ has '+name'   => (default => 'pearson-correlation');
 method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray] $preds)
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds);
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         AI::MXNet::Metric::check_label_shapes($label, $pred);
         $label = $label->aspdl->flat;
         $pred  = $pred->aspdl->flat;
@@ -583,7 +583,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
             ((($label-$label_mean)*($pred-$pred_mean))->sum/$label->nelem)/(($label_stdv*$pred_stdv)->at(0))
         );
         $self->num_inst($self->num_inst + 1);
-    }, $labels, $preds);
+    }
 }
 
 package AI::MXNet::Loss;
@@ -749,8 +749,8 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
 {
     AI::MXNet::Metric::check_label_shapes($labels, $preds)
         unless $self->allow_extra_outputs;
-    zip(sub {
-        my ($label, $pred) = @_;
+    for(zip($labels, $preds)) {
+        my ($label, $pred) = @$_;
         $label = $label->aspdl;
         $pred =  $pred->aspdl;
         my $value = $self->eval_function->($label, $pred);
@@ -758,7 +758,7 @@ method update(ArrayRef[AI::MXNet::NDArray] $labels, ArrayRef[AI::MXNet::NDArray]
         my $num_inst   = ref $value ? $value->[1] : 1;
         $self->sum_metric($self->sum_metric + $sum_metric);
         $self->num_inst($self->num_inst + $num_inst);
-    }, $labels, $preds);
+    }
 }
 
 package AI::MXNet::Metric;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Module.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Module.pm
index a1aa1b2f9769..3229d22597d0 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Module.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Module.pm
@@ -809,12 +809,12 @@ method forward(
         else
         {
             $new_dshape = [];
-            zip(sub {
-                my ($i, $shape) = @_;
+            for(zip($self->data_shapes, \@new_data_shapes)) {
+                my ($i, $shape) = @$_;
                 push @{ $new_dshape }, AI::MXNet::DataDesc->new(
                     $i->name, $shape, $i->dtype, $i->layout
                 );
-            }, $self->data_shapes, \@new_data_shapes);
+            }
         }
         my $new_lshape;
         if($data_batch->can('provide_label') and $data_batch->provide_label)
@@ -824,12 +824,12 @@ method forward(
         elsif($data_batch->can('label') and $data_batch->label)
         {
             $new_lshape = [];
-            zip(sub {
-                my ($i, $j) = @_;
+            for(zip($self->label_shapes, $data_batch->label)) {
+                my ($i, $j) = @$_;
                 push @{ $new_lshape }, AI::MXNet::DataDesc->new(
                     $i->name, $j->shape, $i->dtype, $i->layout
                 );
-            }, $self->label_shapes, $data_batch->label);
+            }
         }
         $self->reshape(data_shapes => $new_dshape, label_shapes => $new_lshape);
     }
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Monitor.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Monitor.pm
index 993461713cb6..386164112e65 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Monitor.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Monitor.pm
@@ -145,14 +145,14 @@ method toc()
     }
     for my $exe (@{ $self->exes })
     {
-        zip(sub {
-            my ($name, $array) = @_;
+        for(zip($exe->_symbol->list_arguments, $exe->arg_arrays)) {
+            my ($name, $array) = @$_;
             push @{ $self->queue }, [$self->step, $name, $self->stat_func->($array)];
-        }, $exe->_symbol->list_arguments, $exe->arg_arrays);
-        zip(sub {
-            my ($name, $array) = @_;
+        }
+        for(zip($exe->_symbol->list_auxiliary_states, $exe->aux_arrays)) {
+            my ($name, $array) = @$_;
             push @{ $self->queue }, [$self->step, $name, $self->stat_func->($array)];
-        }, $exe->_symbol->list_auxiliary_states, $exe->aux_arrays);
+        }
     }
     $self->activated(0);
     my @res;
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/NDArray.pm b/perl-package/AI-MXNet/lib/AI/MXNet/NDArray.pm
index 7193f526b892..ffee1295d0db 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/NDArray.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/NDArray.pm
@@ -96,12 +96,12 @@ method at(Index @indices)
                    or full crop")
         if $isize > 1 and $dsize != $isize;
     my $i = 0;
-    zip(sub {
-        my ($idx, $dim_size) = @_;
+    for(zip(\@indices, $shape)) {
+        my ($idx, $dim_size) = @$_;
         confess("Dimension $i mismatch Idx: $idx >= Dim Size: $dim_size")
             if $idx >= $dim_size or ($idx + $dim_size) < 0;
         ++$i;
-    }, \@indices, $shape);
+    }
     $i = 0;
     for my $v (@indices)
     {
@@ -151,8 +151,8 @@ method slice(Slice|AdvancedSlice @slices)
         ++$i;
         ref $_ ? (@$_ == 1 ? [$_->[0], $_->[0]] : $_) : ($_ eq 'X' ? [0, $shape->[$i] - 1] : [$_, $_]);
     } @slices;
-    zip(sub {
-        my ($slice, $dim_size) = @_;
+    for(zip(\@slices, $shape)) {
+        my ($slice, $dim_size) = @$_;
         my ($begin, $end, $stride) = @$slice;
         confess("NDArray does not support slice strides != 1")
             if ($stride//0) > 1;
@@ -160,7 +160,7 @@ method slice(Slice|AdvancedSlice @slices)
             if $begin >= $dim_size or ($begin + $dim_size) < 0;
         confess("Dimension $i mismatch slice end : $end >= Dim Size: $dim_size")
             if $end >= $dim_size or ($end + $dim_size) < 0;
-    }, \@slices, $shape);
+    }
     $i = 0;
     my ($begin, $end) = ([], []);
     for my $s (@slices)
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/NDArray/Slice.pm b/perl-package/AI-MXNet/lib/AI/MXNet/NDArray/Slice.pm
index ea49ac5960a4..1a3ea7e0a460 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/NDArray/Slice.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/NDArray/Slice.pm
@@ -55,12 +55,10 @@ method set(AcceptableInput $value, $reverse=)
 {
     confess("set value must be defined") unless defined $value;
     confess("${\ $self->parent } is not writable") unless $self->parent->writable;
-    my $shape = [];
-    zip(
-        sub { my ($begin, $end) = @_; push @$shape, ($end-$begin); },
-        $self->begin,
-        $self->end
-    );
+    my $shape = [ map {
+        my($begin, $end) = @$_;
+        ($end-$begin);
+    } zip($self->begin, $self->end) ];
     if(ref $value)
     {
         if(blessed($value) and $value->isa('AI::MXNet::NDArray'))
@@ -77,15 +75,11 @@ method set(AcceptableInput $value, $reverse=)
         }
         confess("value $value does not match slice dim sizes [@$shape]")
             if @{$value->shape} != @$shape;
-        zip(
-            sub {
-                my ($dsize, $vdsize) = @_;
+        for(zip($shape, $value->shape)) {
+                my ($dsize, $vdsize) = @$_;
                 confess("Slice [@$shape]  != $value given as value")
                     if $dsize != $vdsize;
-            },
-            $shape,
-            $value->shape
-        );
+        }
         AI::MXNet::NDArray->_crop_assign(
             $self->parent,
             $value,
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/RNN/Cell.pm b/perl-package/AI-MXNet/lib/AI/MXNet/RNN/Cell.pm
index 38db4090556e..f2d8b5369e99 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/RNN/Cell.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/RNN/Cell.pm
@@ -1412,15 +1412,15 @@ method unroll(
         $r_outputs = [reverse(@{ $r_outputs })];
     }
     my $outputs = [];
-    zip(sub {
-        my ($i, $l_o, $r_o) = @_;
+    for(zip([0..@{ $l_outputs }-1], [@{ $l_outputs }], [@{ $r_outputs }])) {
+        my ($i, $l_o, $r_o) = @$_;
         push @$outputs, AI::MXNet::Symbol->Concat(
             $l_o, $r_o, dim=>(1+($merge_outputs?1:0)),
             name => $merge_outputs
                         ? sprintf('%sout', $self->_output_prefix)
                         : sprintf('%st%d', $self->_output_prefix, $i)
         );
-    }, [0..@{ $l_outputs }-1], [@{ $l_outputs }], [@{ $r_outputs }]);
+    }
     if($merge_outputs)
     {
         $outputs = @{ $outputs }[0];
@@ -1907,14 +1907,14 @@ method call(AI::MXNet::Symbol $inputs, SymbolOrArrayOfSymbols $states)
     my @states;
     if($p_states != 0)
     {
-        zip(sub {
-            my ($new_s, $old_s) = @_;
+        for(zip($next_states, $states)) {
+            my ($new_s, $old_s) = @$_;
             push @states, AI::MXNet::Symbol->where(
                 $mask->($p_states, $new_s),
                 $new_s,
                 $old_s
             );
-        }, $next_states, $states);
+        }
     }
     $self->prev_output($output);
     return ($output, @states ? \@states : $next_states);
@@ -1968,11 +1968,11 @@ method unroll(
     else
     {
         my @temp;
-        zip(sub {
-            my ($output_sym, $input_sym) = @_;
+        for(zip([@{ $outputs }], [@{ $inputs }])) {
+            my ($output_sym, $input_sym) = @$_;
             push @temp, AI::MXNet::Symbol->elemwise_add($output_sym, $input_sym,
                             name=>$output_sym->name."_plus_residual");
-        }, [@{ $outputs }], [@{ $inputs }]);
+        }
         $outputs = \@temp;
     }
     return ($outputs, $states);
diff --git a/perl-package/AI-MXNet/lib/AI/MXNet/Symbol.pm b/perl-package/AI-MXNet/lib/AI/MXNet/Symbol.pm
index d35bdaea62cd..8fd885a1d2c8 100644
--- a/perl-package/AI-MXNet/lib/AI/MXNet/Symbol.pm
+++ b/perl-package/AI-MXNet/lib/AI/MXNet/Symbol.pm
@@ -585,8 +585,8 @@ method infer_shape(Maybe[Str|Shape] @args)
         my ($arg_shapes) = $self->_infer_shape_impl(1, @args);
         my $arg_names    = $self->list_arguments;
         my @unknowns;
-        zip(sub {
-            my ($name, $shape) = @_;
+        for(zip($arg_names, $arg_shapes)) {
+            my ($name, $shape) = @$_;
             if(not ref $shape or not @$shape or not product(@$shape))
             {
                 if(@unknowns >= 10)
@@ -599,7 +599,7 @@ method infer_shape(Maybe[Str|Shape] @args)
                     push @unknowns, "$name @shape";
                 }
             }
-        }, $arg_names, $arg_shapes);
+        }
         AI::MXNet::Logging->warning(
             "Cannot decide shape for the following arguments "
             ."(0s in shape means unknown dimensions). "
diff --git a/perl-package/AI-MXNet/t/test_autograd.t b/perl-package/AI-MXNet/t/test_autograd.t
index 32225bfd2728..b45d233d79a0 100644
--- a/perl-package/AI-MXNet/t/test_autograd.t
+++ b/perl-package/AI-MXNet/t/test_autograd.t
@@ -37,10 +37,10 @@ sub autograd_assert
     ok(same($output->aspdl, $res->aspdl));
     my $grad_res = $grad_f->(@args);
     ok(@$grad_vals == @$grad_res);
-    zip(sub {
-        my ($a, $b) = @_;
+    for(zip($grad_vals, $grad_res)) {
+        my ($a, $b) = @$_;
         ok(same($a->aspdl, $b->aspdl));
-    }, $grad_vals, $grad_res);
+    }
 }
 
 sub test_unary_func
diff --git a/perl-package/AI-MXNet/t/test_base.t b/perl-package/AI-MXNet/t/test_base.t
new file mode 100644
index 000000000000..ea0bd0ef98f3
--- /dev/null
+++ b/perl-package/AI-MXNet/t/test_base.t
@@ -0,0 +1,107 @@
+use strict;
+use warnings;
+use Test::More;
+use AI::MXNet qw(mx);
+
+sub test_builtin_zip()
+{
+    is_deeply(
+        [ AI::MXNet::zip([ 0 .. 9 ], [ 10 .. 19 ]) ],
+        [ map { [ $_, 10 + $_ ] } 0 .. 9 ]);
+    is_deeply(
+        [ AI::MXNet::zip([ 0 .. 9 ], [ 10 .. 19 ], [ 20 .. 29 ]) ],
+        [ map { [ $_, 10 + $_, 20 + $_ ] } 0 .. 9 ]);
+    my $over = ListOverload->new(10 .. 19);
+    is_deeply(
+        [ AI::MXNet::zip([ 0 .. 9 ], \@$over) ],
+        [ map { [ $_, 10 + $_ ] } 0 .. 9 ]);
+    my $tied = ListTied->new(10 .. 19);
+    is_deeply(
+        [ AI::MXNet::zip([ 0 .. 9 ], \@$tied) ],
+        [ map { [ $_, 10 + $_ ] } 0 .. 9 ]);
+}
+
+
+test_builtin_zip();
+done_testing();
+
+package ListTied {
+    sub new {
+        my($class, @list) = @_;
+        my @tied;
+        tie @tied, $class, @list;
+        return \@tied;
+    }
+    sub TIEARRAY {
+        my($class, @list) = @_;
+        return bless { list => \@list }, $class;
+    }
+    sub FETCH {
+        my($self, $index) = @_;
+        return $self->{list}[$index];
+    }
+    sub STORE {
+        my($self, $index, $value) = @_;
+        return $self->{list}[$index] = $value;
+    }
+    sub FETCHSIZE {
+        my($self) = @_;
+        return scalar @{$self->{list}};
+    }
+    sub STORESIZE {
+        my($self, $count) = @_;
+        return $self->{list}[$count - 1] //= undef;
+    }
+    sub EXTEND {
+        my($self, $count) = @_;
+        return $self->STORESIZE($count);
+    }
+    sub EXISTS {
+        my($self, $key) = @_;
+        return exists $self->{list}[$key];
+    }
+    sub DELETE {
+        my($self, $key) = @_;
+        return delete $self->{list}[$key];
+    }
+    sub CLEAR {
+        my($self) = @_;
+        return @{$self->{list}} = ();
+    }
+    sub PUSH {
+        my($self, @list) = @_;
+        return push @{$self->{list}}, @list;
+    }
+    sub POP {
+        my($self) = @_;
+        return pop @{$self->{list}};
+    }
+    sub SHIFT {
+        my($self) = @_;
+        return shift @{$self->{list}};
+    }
+    sub UNSHIFT {
+        my($self, @list) = @_;
+        return unshift @{$self->{list}}, @list;
+    }
+    sub SPLICE {
+        my($self, $offset, $length, @list) = @_;
+        return splice @{$self->{list}}, $offset, $length, @list;
+    }
+    sub UNTIE {
+        my($self) = @_;
+    }
+    sub DESTROY {
+        my($self) = @_;
+    }
+}
+
+package ListOverload {
+    use overload '@{}' => \&as_list;
+    sub new {
+        my($class, @list) = @_;
+        return bless { list => \@list }, $class;
+    }
+    sub as_list { return $_[0]{list} }
+}
+
diff --git a/perl-package/AI-MXNet/t/test_model_parallel.t b/perl-package/AI-MXNet/t/test_model_parallel.t
index 6a8aba7aab06..76fe25625be3 100644
--- a/perl-package/AI-MXNet/t/test_model_parallel.t
+++ b/perl-package/AI-MXNet/t/test_model_parallel.t
@@ -65,10 +65,10 @@ sub test_chain
     $out_grad .= 1;
     $exec1->backward([$out_grad]);
     $exec2->backward([$out_grad->copyto($ctx1)]);
-    zip(sub {
-        my ($a, $b) = @_;
+    for(zip($arr_grad, $arr_grad2)) {
+        my ($a, $b) = @$_;
         ok(reldiff($a->aspdl, $b->aspdl) < 1e-6);
-    }, $arr_grad, $arr_grad2);
+    }
 }
 
 test_chain();
diff --git a/perl-package/AI-MXNet/t/test_module.t b/perl-package/AI-MXNet/t/test_module.t
index 7c5690a68b15..305b232a7222 100644
--- a/perl-package/AI-MXNet/t/test_module.t
+++ b/perl-package/AI-MXNet/t/test_module.t
@@ -148,10 +148,10 @@ sub test_module_states
     $mod->forward($batch);
     my $out2 = $mod->get_outputs(1);
 
-    zip(sub {
-        my ($x1, $x2) = @_;
+    for(zip($out1, $out2)) {
+        my ($x1, $x2) = @$_;
         ok(not almost_equal($x1->aspdl, $x2->aspdl, 1e-3));
-    }, $out1, $out2);
+    }
 }
 
 sub test_module_switch_bucket
@@ -619,4 +619,4 @@ test_module_reshape();
 test_save_load();
 test_executor_group();
 test_module_set_params();
-test_forward_reshape();
\ No newline at end of file
+test_forward_reshape();
diff --git a/perl-package/AI-MXNet/t/test_multi_device_exec.t b/perl-package/AI-MXNet/t/test_multi_device_exec.t
index 87ca25778c92..15111a7a5d80 100644
--- a/perl-package/AI-MXNet/t/test_multi_device_exec.t
+++ b/perl-package/AI-MXNet/t/test_multi_device_exec.t
@@ -41,8 +41,8 @@ sub test_ctx_group
         shapes    => { data => [1,200] }
     );
 
-    zip(sub {
-        my ($arr, $name) = @_;
+    for(zip($texec->arg_arrays, $mlp->list_arguments())) {
+        my ($arr, $name) = @$_;
         if(exists $set_stage1{ $name })
         {
             ok($arr->context == $group2ctx->{stage1});
@@ -51,7 +51,7 @@ sub test_ctx_group
         {
             ok($arr->context == $group2ctx->{stage2});
         }
-    }, $texec->arg_arrays, $mlp->list_arguments());
+    }
 }
 
 test_ctx_group();
diff --git a/perl-package/AI-MXNetCAPI/mxnet.i b/perl-package/AI-MXNetCAPI/mxnet.i
index e466e98b7842..663a0c285f0b 100644
--- a/perl-package/AI-MXNetCAPI/mxnet.i
+++ b/perl-package/AI-MXNetCAPI/mxnet.i
@@ -106,7 +106,44 @@ static void ExecutorMonitor_callback(const char* name, NDArrayHandle handle, voi
 
 %}
 
+%{
+
+/* this is an adaptation of Python/bltinmodule.c's builtin_zip() */
+XS(py_zip) {
+    dXSARGS;
+    I32 i;
+    I32 len = -1;
+    AV *l[items];
+
+    for(i = 0; i < items; i++) {
+        AV *av = (AV *)SvRV(ST(i));
+        I32 thislen;
+
+        if(SvTYPE(av) != SVt_PVAV)
+            croak("zip argument#%d must be an array", i);
+        thislen = av_len(av) + 1;
+        if(len < 0 || thislen < len)
+            len = thislen;
+        l[i] = av;
+    }
+    EXTEND(SP, len);
+    for(i = 0; i < len; i++) {
+        I32 j;
+        SV *next[items];
+
+        for(j = 0; j < items; j++) {
+            SV **sv = av_fetch(l[j], i, 0);
+            next[j] = sv ? *sv : &PL_sv_undef;
+        }
+        ST(i) = sv_2mortal(newRV_noinc((SV *)av_make(items, next)));
+    }
+    XSRETURN(len);
+}
+
+%}
+
 %init %{
+    newXS(SWIG_prefix "py_zip", py_zip, (char *)__FILE__);
     /* These SWIG_TypeClientData() calls might break in the future, but
      * %rename should work on these types before that happens. */
     SWIG_TypeClientData(SWIGTYPE_p_MXNDArray, (void *)"NDArrayHandle");