diff --git a/src/api.rs b/src/api.rs
index 14fb4083..8018e447 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -177,10 +177,12 @@ impl Engine {
     /// Register an iterator adapter for an iterable type with the `Engine`.
     /// This is an advanced feature.
     #[inline(always)]
-    pub fn register_iterator<T: Variant + Clone + IntoIterator<Item = U>, U: Variant + Clone>(
-        &mut self,
-    ) -> &mut Self {
-        self.global_module.set_iterable::<T, U>();
+    pub fn register_iterator<T>(&mut self) -> &mut Self
+    where
+        T: Variant + Clone + Iterator,
+        <T as Iterator>::Item: Variant + Clone,
+    {
+        self.global_module.set_iterable::<T>();
         self
     }
 
diff --git a/src/module/mod.rs b/src/module/mod.rs
index ed135f71..d7cc40d9 100644
--- a/src/module/mod.rs
+++ b/src/module/mod.rs
@@ -1469,18 +1469,22 @@ impl Module {
     }
 
     /// Set a type iterator into the module.
-    pub fn set_iterable<T: Variant + Clone + IntoIterator<Item = U>, U: Variant + Clone>(
-        &mut self,
-    ) -> &mut Self {
+    pub fn set_iterable<T>(&mut self) -> &mut Self
+    where
+        T: Variant + Clone + IntoIterator,
+        <T as IntoIterator>::Item: Variant + Clone,
+    {
         self.set_iter(TypeId::of::<T>(), |obj: Dynamic| {
             Box::new(obj.cast::<T>().into_iter().map(Dynamic::from))
         })
     }
 
     /// Set an iterator type into the module as a type iterator.
-    pub fn set_iterator<T: Variant + Clone + Iterator<Item = U>, U: Variant + Clone>(
-        &mut self,
-    ) -> &mut Self {
+    pub fn set_iterator<T>(&mut self) -> &mut Self
+    where
+        T: Variant + Clone + Iterator,
+        <T as Iterator>::Item: Variant + Clone,
+    {
         self.set_iter(TypeId::of::<T>(), |obj: Dynamic| {
             Box::new(obj.cast::<T>().map(Dynamic::from))
         })
diff --git a/src/packages/array_basic.rs b/src/packages/array_basic.rs
index 43543ad8..de5bdfcc 100644
--- a/src/packages/array_basic.rs
+++ b/src/packages/array_basic.rs
@@ -86,7 +86,7 @@ def_package!(crate:BasicArrayPackage:"Basic array utilities.", lib, {
     combine_with_exported_module!(lib, "array", array_functions);
 
     // Register array iterator
-    lib.set_iterable::<Array, Dynamic>();
+    lib.set_iterable::<Array>();
 });
 
 #[export_module]
diff --git a/src/packages/iter_basic.rs b/src/packages/iter_basic.rs
index eaf74fe0..c4832c95 100644
--- a/src/packages/iter_basic.rs
+++ b/src/packages/iter_basic.rs
@@ -1,18 +1,10 @@
 use crate::any::Variant;
 use crate::def_package;
-use crate::module::{FuncReturn, Module};
+use crate::module::FuncReturn;
 use crate::parser::INT;
 
 use crate::stdlib::ops::{Add, Range};
 
-// Register range function
-fn reg_range<T: Variant + Clone>(lib: &mut Module)
-where
-    Range<T>: Iterator<Item = T>,
-{
-    lib.set_iterator::<Range<T>, T>();
-}
-
 fn get_range<T: Variant + Clone>(from: T, to: T) -> FuncReturn<Range<T>> {
     Ok(from..to)
 }
@@ -42,15 +34,6 @@ where
     }
 }
 
-fn reg_step<T>(lib: &mut Module)
-where
-    for<'a> &'a T: Add<&'a T, Output = T>,
-    T: Variant + Clone + PartialOrd,
-    StepRange<T>: Iterator<Item = T>,
-{
-    lib.set_iterator::<StepRange<T>, T>();
-}
-
 fn get_step_range<T>(from: T, to: T, step: T) -> FuncReturn<StepRange<T>>
 where
     for<'a> &'a T: Add<&'a T, Output = T>,
@@ -60,14 +43,15 @@ where
 }
 
 def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
-    reg_range::<INT>(lib);
+    lib.set_iterator::<Range<INT>>();
+
     lib.set_fn_2("range", get_range::<INT>);
 
     if cfg!(not(feature = "only_i32")) && cfg!(not(feature = "only_i64")) {
         macro_rules! reg_range {
             ($lib:expr, $x:expr, $( $y:ty ),*) => (
                 $(
-                    reg_range::<$y>($lib);
+                    $lib.set_iterator::<Range<$y>>();
                     $lib.set_fn_2($x, get_range::<$y>);
                 )*
             )
@@ -80,14 +64,14 @@ def_package!(crate:BasicIteratorPackage:"Basic range iterators.", lib, {
         }
     }
 
-    reg_step::<INT>(lib);
+    lib.set_iterator::<StepRange<INT>>();
     lib.set_fn_3("range", get_step_range::<INT>);
 
     if cfg!(not(feature = "only_i32")) && cfg!(not(feature = "only_i64")) {
         macro_rules! reg_step {
             ($lib:expr, $x:expr, $( $y:ty ),*) => (
                 $(
-                    reg_step::<$y>($lib);
+                    $lib.set_iterator::<StepRange<$y>>();
                     $lib.set_fn_3($x, get_step_range::<$y>);
                 )*
             )
diff --git a/src/packages/map_basic.rs b/src/packages/map_basic.rs
index 099f546c..26fc3fe3 100644
--- a/src/packages/map_basic.rs
+++ b/src/packages/map_basic.rs
@@ -6,7 +6,8 @@ use crate::engine::Map;
 use crate::parser::{ImmutableString, INT};
 use crate::plugin::*;
 
-use crate::stdlib::vec::Vec;
+#[cfg(not(feature = "no_index"))]
+use crate::engine::Array;
 
 def_package!(crate:BasicMapPackage:"Basic object map utilities.", lib, {
     combine_with_exported_module!(lib, "map", map_functions);
@@ -47,10 +48,10 @@ mod map_functions {
 
     #[cfg(not(feature = "no_index"))]
     pub mod indexing {
-        pub fn keys(map: &mut Map) -> Vec<Dynamic> {
+        pub fn keys(map: &mut Map) -> Array {
             map.iter().map(|(k, _)| k.clone().into()).collect()
         }
-        pub fn values(map: &mut Map) -> Vec<Dynamic> {
+        pub fn values(map: &mut Map) -> Array {
             map.iter().map(|(_, v)| v.clone()).collect()
         }
     }