diff --git a/src/func/call.rs b/src/func/call.rs
index 87478c71..7e6b1c38 100644
--- a/src/func/call.rs
+++ b/src/func/call.rs
@@ -1,6 +1,7 @@
 //! Implement function-calling mechanism for [`Engine`].
 
-use super::native::{CallableFunction, FnAny};
+use super::callable_function::CallableFunction;
+use super::native::FnAny;
 use super::{get_builtin_binary_op_fn, get_builtin_op_assignment_fn};
 use crate::api::default_limits::MAX_DYNAMIC_PARAMETERS;
 use crate::ast::FnCallHashes;
diff --git a/src/func/callable_function.rs b/src/func/callable_function.rs
new file mode 100644
index 00000000..251c4d06
--- /dev/null
+++ b/src/func/callable_function.rs
@@ -0,0 +1,250 @@
+//! Module defining the standard Rhai function type.
+
+use super::native::{FnAny, FnPlugin, IteratorFn, SendSync};
+use crate::ast::FnAccess;
+use crate::plugin::PluginFunction;
+use crate::Shared;
+use std::fmt;
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+/// A type encapsulating a function callable by Rhai.
+#[derive(Clone)]
+pub enum CallableFunction {
+    /// A pure native Rust function with all arguments passed by value.
+    Pure(Shared<FnAny>),
+    /// A native Rust object method with the first argument passed by reference,
+    /// and the rest passed by value.
+    Method(Shared<FnAny>),
+    /// An iterator function.
+    Iterator(IteratorFn),
+    /// A plugin function,
+    Plugin(Shared<FnPlugin>),
+    /// A script-defined function.
+    ///
+    /// Not available under `no_function`.
+    #[cfg(not(feature = "no_function"))]
+    Script(Shared<crate::ast::ScriptFnDef>),
+}
+
+impl fmt::Debug for CallableFunction {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Pure(_) => write!(f, "NativePureFunction"),
+            Self::Method(_) => write!(f, "NativeMethod"),
+            Self::Iterator(_) => write!(f, "NativeIterator"),
+            Self::Plugin(_) => write!(f, "PluginFunction"),
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(fn_def) => fmt::Debug::fmt(fn_def, f),
+        }
+    }
+}
+
+impl fmt::Display for CallableFunction {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Pure(_) => write!(f, "NativePureFunction"),
+            Self::Method(_) => write!(f, "NativeMethod"),
+            Self::Iterator(_) => write!(f, "NativeIterator"),
+            Self::Plugin(_) => write!(f, "PluginFunction"),
+
+            #[cfg(not(feature = "no_function"))]
+            CallableFunction::Script(s) => fmt::Display::fmt(s, f),
+        }
+    }
+}
+
+impl CallableFunction {
+    /// Is this a pure native Rust function?
+    #[inline]
+    #[must_use]
+    pub fn is_pure(&self) -> bool {
+        match self {
+            Self::Pure(_) => true,
+            Self::Method(_) | Self::Iterator(_) => false,
+
+            Self::Plugin(p) => !p.is_method_call(),
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
+        }
+    }
+    /// Is this a native Rust method function?
+    #[inline]
+    #[must_use]
+    pub fn is_method(&self) -> bool {
+        match self {
+            Self::Method(_) => true,
+            Self::Pure(_) | Self::Iterator(_) => false,
+
+            Self::Plugin(p) => p.is_method_call(),
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
+        }
+    }
+    /// Is this an iterator function?
+    #[inline]
+    #[must_use]
+    pub const fn is_iter(&self) -> bool {
+        match self {
+            Self::Iterator(_) => true,
+            Self::Pure(_) | Self::Method(_) | Self::Plugin(_) => false,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
+        }
+    }
+    /// Is this a script-defined function?
+    #[inline]
+    #[must_use]
+    pub const fn is_script(&self) -> bool {
+        match self {
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => true,
+
+            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) | Self::Plugin(_) => false,
+        }
+    }
+    /// Is this a plugin function?
+    #[inline]
+    #[must_use]
+    pub const fn is_plugin_fn(&self) -> bool {
+        match self {
+            Self::Plugin(_) => true,
+            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => false,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
+        }
+    }
+    /// Is this a native Rust function?
+    #[inline]
+    #[must_use]
+    pub const fn is_native(&self) -> bool {
+        match self {
+            Self::Pure(_) | Self::Method(_) => true,
+            Self::Plugin(_) => true,
+            Self::Iterator(_) => true,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
+        }
+    }
+    /// Get the access mode.
+    #[inline]
+    #[must_use]
+    pub fn access(&self) -> FnAccess {
+        match self {
+            Self::Plugin(_) => FnAccess::Public,
+            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => FnAccess::Public,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(f) => f.access,
+        }
+    }
+    /// Get a shared reference to a native Rust function.
+    #[inline]
+    #[must_use]
+    pub fn get_native_fn(&self) -> Option<&Shared<FnAny>> {
+        match self {
+            Self::Pure(f) | Self::Method(f) => Some(f),
+            Self::Iterator(_) | Self::Plugin(_) => None,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => None,
+        }
+    }
+    /// Get a shared reference to a script-defined function definition.
+    ///
+    /// Not available under `no_function`.
+    #[cfg(not(feature = "no_function"))]
+    #[inline]
+    #[must_use]
+    pub const fn get_script_fn_def(&self) -> Option<&Shared<crate::ast::ScriptFnDef>> {
+        match self {
+            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) | Self::Plugin(_) => None,
+            Self::Script(f) => Some(f),
+        }
+    }
+    /// Get a reference to an iterator function.
+    #[inline]
+    #[must_use]
+    pub fn get_iter_fn(&self) -> Option<IteratorFn> {
+        match self {
+            Self::Iterator(f) => Some(*f),
+            Self::Pure(_) | Self::Method(_) | Self::Plugin(_) => None,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => None,
+        }
+    }
+    /// Get a shared reference to a plugin function.
+    #[inline]
+    #[must_use]
+    pub fn get_plugin_fn(&self) -> Option<&Shared<FnPlugin>> {
+        match self {
+            Self::Plugin(f) => Some(f),
+            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => None,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => None,
+        }
+    }
+    /// Create a new [`CallableFunction::Pure`].
+    #[inline(always)]
+    #[must_use]
+    pub fn from_pure(func: Box<FnAny>) -> Self {
+        Self::Pure(func.into())
+    }
+    /// Create a new [`CallableFunction::Method`].
+    #[inline(always)]
+    #[must_use]
+    pub fn from_method(func: Box<FnAny>) -> Self {
+        Self::Method(func.into())
+    }
+    /// Create a new [`CallableFunction::Plugin`].
+    #[inline(always)]
+    #[must_use]
+    pub fn from_plugin(func: impl PluginFunction + 'static + SendSync) -> Self {
+        Self::Plugin((Box::new(func) as Box<FnPlugin>).into())
+    }
+}
+
+impl From<IteratorFn> for CallableFunction {
+    #[inline(always)]
+    fn from(func: IteratorFn) -> Self {
+        Self::Iterator(func)
+    }
+}
+
+#[cfg(not(feature = "no_function"))]
+impl From<crate::ast::ScriptFnDef> for CallableFunction {
+    #[inline(always)]
+    fn from(_func: crate::ast::ScriptFnDef) -> Self {
+        Self::Script(_func.into())
+    }
+}
+
+#[cfg(not(feature = "no_function"))]
+impl From<Shared<crate::ast::ScriptFnDef>> for CallableFunction {
+    #[inline(always)]
+    fn from(_func: Shared<crate::ast::ScriptFnDef>) -> Self {
+        Self::Script(_func)
+    }
+}
+
+impl<T: PluginFunction + 'static + SendSync> From<T> for CallableFunction {
+    #[inline(always)]
+    fn from(func: T) -> Self {
+        Self::from_plugin(func)
+    }
+}
+
+impl From<Shared<FnPlugin>> for CallableFunction {
+    #[inline(always)]
+    fn from(func: Shared<FnPlugin>) -> Self {
+        Self::Plugin(func)
+    }
+}
diff --git a/src/func/mod.rs b/src/func/mod.rs
index 1d5a0841..dcae0482 100644
--- a/src/func/mod.rs
+++ b/src/func/mod.rs
@@ -3,6 +3,7 @@
 pub mod args;
 pub mod builtin;
 pub mod call;
+pub mod callable_function;
 pub mod func;
 pub mod hashing;
 pub mod native;
@@ -13,6 +14,7 @@ pub mod script;
 pub use args::FuncArgs;
 pub use builtin::{get_builtin_binary_op_fn, get_builtin_op_assignment_fn};
 pub use call::FnCallArgs;
+pub use callable_function::CallableFunction;
 #[cfg(not(feature = "no_function"))]
 pub use func::Func;
 pub use hashing::{
@@ -20,8 +22,8 @@ pub use hashing::{
     combine_hashes, get_hasher,
 };
 pub use native::{
-    shared_make_mut, shared_take, shared_take_or_clone, shared_try_take, shared_write_lock,
-    CallableFunction, FnAny, FnPlugin, IteratorFn, Locked, NativeCallContext, SendSync, Shared,
+    shared_make_mut, shared_take, shared_take_or_clone, shared_try_take, shared_write_lock, FnAny,
+    FnPlugin, IteratorFn, Locked, NativeCallContext, SendSync, Shared,
 };
 pub use plugin::PluginFunction;
 pub use register::RegisterNativeFunction;
diff --git a/src/func/native.rs b/src/func/native.rs
index f23d04b4..56a8edfc 100644
--- a/src/func/native.rs
+++ b/src/func/native.rs
@@ -1,7 +1,7 @@
 //! Module defining interfaces to native-Rust functions.
 
 use super::call::FnCallArgs;
-use crate::ast::{FnAccess, FnCallHashes};
+use crate::ast::FnCallHashes;
 use crate::engine::{EvalState, Imports};
 use crate::plugin::PluginFunction;
 use crate::tokenizer::{Token, TokenizeState};
@@ -10,9 +10,9 @@ use crate::{
     calc_fn_hash, Dynamic, Engine, EvalAltResult, EvalContext, FuncArgs, Module, Position,
     RhaiResult, StaticVec,
 };
+use std::any::type_name;
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
-use std::{any::type_name, fmt};
 
 /// Trait that maps to `Send + Sync` only under the `sync` feature.
 #[cfg(feature = "sync")]
@@ -414,244 +414,3 @@ pub type OnVarCallback = Box<
         + Sync
         + 'static,
 >;
-
-/// A type encapsulating a function callable by Rhai.
-#[derive(Clone)]
-pub enum CallableFunction {
-    /// A pure native Rust function with all arguments passed by value.
-    Pure(Shared<FnAny>),
-    /// A native Rust object method with the first argument passed by reference,
-    /// and the rest passed by value.
-    Method(Shared<FnAny>),
-    /// An iterator function.
-    Iterator(IteratorFn),
-    /// A plugin function,
-    Plugin(Shared<FnPlugin>),
-    /// A script-defined function.
-    ///
-    /// Not available under `no_function`.
-    #[cfg(not(feature = "no_function"))]
-    Script(Shared<crate::ast::ScriptFnDef>),
-}
-
-impl fmt::Debug for CallableFunction {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Pure(_) => write!(f, "NativePureFunction"),
-            Self::Method(_) => write!(f, "NativeMethod"),
-            Self::Iterator(_) => write!(f, "NativeIterator"),
-            Self::Plugin(_) => write!(f, "PluginFunction"),
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(fn_def) => fmt::Debug::fmt(fn_def, f),
-        }
-    }
-}
-
-impl fmt::Display for CallableFunction {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Pure(_) => write!(f, "NativePureFunction"),
-            Self::Method(_) => write!(f, "NativeMethod"),
-            Self::Iterator(_) => write!(f, "NativeIterator"),
-            Self::Plugin(_) => write!(f, "PluginFunction"),
-
-            #[cfg(not(feature = "no_function"))]
-            CallableFunction::Script(s) => fmt::Display::fmt(s, f),
-        }
-    }
-}
-
-impl CallableFunction {
-    /// Is this a pure native Rust function?
-    #[inline]
-    #[must_use]
-    pub fn is_pure(&self) -> bool {
-        match self {
-            Self::Pure(_) => true,
-            Self::Method(_) | Self::Iterator(_) => false,
-
-            Self::Plugin(p) => !p.is_method_call(),
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => false,
-        }
-    }
-    /// Is this a native Rust method function?
-    #[inline]
-    #[must_use]
-    pub fn is_method(&self) -> bool {
-        match self {
-            Self::Method(_) => true,
-            Self::Pure(_) | Self::Iterator(_) => false,
-
-            Self::Plugin(p) => p.is_method_call(),
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => false,
-        }
-    }
-    /// Is this an iterator function?
-    #[inline]
-    #[must_use]
-    pub const fn is_iter(&self) -> bool {
-        match self {
-            Self::Iterator(_) => true,
-            Self::Pure(_) | Self::Method(_) | Self::Plugin(_) => false,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => false,
-        }
-    }
-    /// Is this a script-defined function?
-    #[inline]
-    #[must_use]
-    pub const fn is_script(&self) -> bool {
-        match self {
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => true,
-
-            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) | Self::Plugin(_) => false,
-        }
-    }
-    /// Is this a plugin function?
-    #[inline]
-    #[must_use]
-    pub const fn is_plugin_fn(&self) -> bool {
-        match self {
-            Self::Plugin(_) => true,
-            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => false,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => false,
-        }
-    }
-    /// Is this a native Rust function?
-    #[inline]
-    #[must_use]
-    pub const fn is_native(&self) -> bool {
-        match self {
-            Self::Pure(_) | Self::Method(_) => true,
-            Self::Plugin(_) => true,
-            Self::Iterator(_) => true,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => false,
-        }
-    }
-    /// Get the access mode.
-    #[inline]
-    #[must_use]
-    pub fn access(&self) -> FnAccess {
-        match self {
-            Self::Plugin(_) => FnAccess::Public,
-            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => FnAccess::Public,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(f) => f.access,
-        }
-    }
-    /// Get a shared reference to a native Rust function.
-    #[inline]
-    #[must_use]
-    pub fn get_native_fn(&self) -> Option<&Shared<FnAny>> {
-        match self {
-            Self::Pure(f) | Self::Method(f) => Some(f),
-            Self::Iterator(_) | Self::Plugin(_) => None,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => None,
-        }
-    }
-    /// Get a shared reference to a script-defined function definition.
-    ///
-    /// Not available under `no_function`.
-    #[cfg(not(feature = "no_function"))]
-    #[inline]
-    #[must_use]
-    pub const fn get_script_fn_def(&self) -> Option<&Shared<crate::ast::ScriptFnDef>> {
-        match self {
-            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) | Self::Plugin(_) => None,
-            Self::Script(f) => Some(f),
-        }
-    }
-    /// Get a reference to an iterator function.
-    #[inline]
-    #[must_use]
-    pub fn get_iter_fn(&self) -> Option<IteratorFn> {
-        match self {
-            Self::Iterator(f) => Some(*f),
-            Self::Pure(_) | Self::Method(_) | Self::Plugin(_) => None,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => None,
-        }
-    }
-    /// Get a shared reference to a plugin function.
-    #[inline]
-    #[must_use]
-    pub fn get_plugin_fn(&self) -> Option<&Shared<FnPlugin>> {
-        match self {
-            Self::Plugin(f) => Some(f),
-            Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => None,
-
-            #[cfg(not(feature = "no_function"))]
-            Self::Script(_) => None,
-        }
-    }
-    /// Create a new [`CallableFunction::Pure`].
-    #[inline(always)]
-    #[must_use]
-    pub fn from_pure(func: Box<FnAny>) -> Self {
-        Self::Pure(func.into())
-    }
-    /// Create a new [`CallableFunction::Method`].
-    #[inline(always)]
-    #[must_use]
-    pub fn from_method(func: Box<FnAny>) -> Self {
-        Self::Method(func.into())
-    }
-    /// Create a new [`CallableFunction::Plugin`].
-    #[inline(always)]
-    #[must_use]
-    pub fn from_plugin(func: impl PluginFunction + 'static + SendSync) -> Self {
-        Self::Plugin((Box::new(func) as Box<FnPlugin>).into())
-    }
-}
-
-impl From<IteratorFn> for CallableFunction {
-    #[inline(always)]
-    fn from(func: IteratorFn) -> Self {
-        Self::Iterator(func)
-    }
-}
-
-#[cfg(not(feature = "no_function"))]
-impl From<crate::ast::ScriptFnDef> for CallableFunction {
-    #[inline(always)]
-    fn from(_func: crate::ast::ScriptFnDef) -> Self {
-        Self::Script(_func.into())
-    }
-}
-
-#[cfg(not(feature = "no_function"))]
-impl From<Shared<crate::ast::ScriptFnDef>> for CallableFunction {
-    #[inline(always)]
-    fn from(_func: Shared<crate::ast::ScriptFnDef>) -> Self {
-        Self::Script(_func)
-    }
-}
-
-impl<T: PluginFunction + 'static + SendSync> From<T> for CallableFunction {
-    #[inline(always)]
-    fn from(func: T) -> Self {
-        Self::from_plugin(func)
-    }
-}
-
-impl From<Shared<FnPlugin>> for CallableFunction {
-    #[inline(always)]
-    fn from(func: Shared<FnPlugin>) -> Self {
-        Self::Plugin(func)
-    }
-}
diff --git a/src/func/register.rs b/src/func/register.rs
index e317f51b..7230ab02 100644
--- a/src/func/register.rs
+++ b/src/func/register.rs
@@ -2,8 +2,9 @@
 
 #![allow(non_snake_case)]
 
-use crate::func::call::FnCallArgs;
-use crate::func::native::{CallableFunction, FnAny, SendSync};
+use super::call::FnCallArgs;
+use super::callable_function::CallableFunction;
+use super::native::{FnAny, SendSync};
 use crate::r#unsafe::unsafe_try_cast;
 use crate::tokenizer::Position;
 use crate::types::dynamic::{DynamicWriteLock, Variant};
diff --git a/src/func/script.rs b/src/func/script.rs
index 383dd400..1bb56e3f 100644
--- a/src/func/script.rs
+++ b/src/func/script.rs
@@ -1,9 +1,9 @@
 //! Implement script function-calling mechanism for [`Engine`].
 #![cfg(not(feature = "no_function"))]
 
+use super::call::FnCallArgs;
 use crate::ast::ScriptFnDef;
 use crate::engine::{EvalState, Imports};
-use crate::func::call::FnCallArgs;
 use crate::r#unsafe::unsafe_cast_var_name_to_lifetime;
 use crate::{Dynamic, Engine, EvalAltResult, Module, Position, RhaiResult, Scope, StaticVec};
 use std::mem;
diff --git a/src/types/dynamic.rs b/src/types/dynamic.rs
index 26251386..09d24950 100644
--- a/src/types/dynamic.rs
+++ b/src/types/dynamic.rs
@@ -611,14 +611,11 @@ impl fmt::Display for Dynamic {
             #[cfg(feature = "decimal")]
             Union::Decimal(ref value, _, _) => fmt::Display::fmt(value, f),
             #[cfg(not(feature = "no_index"))]
-            Union::Array(ref value, _, _) => fmt::Debug::fmt(value, f),
+            Union::Array(_, _, _) => fmt::Debug::fmt(self, f),
             #[cfg(not(feature = "no_index"))]
-            Union::Blob(ref value, _, _) => fmt::Debug::fmt(value, f),
+            Union::Blob(_, _, _) => fmt::Debug::fmt(self, f),
             #[cfg(not(feature = "no_object"))]
-            Union::Map(ref value, _, _) => {
-                f.write_str("#")?;
-                fmt::Debug::fmt(value, f)
-            }
+            Union::Map(_, _, _) => fmt::Debug::fmt(self, f),
             Union::FnPtr(ref value, _, _) => fmt::Display::fmt(value, f),
             #[cfg(not(feature = "no_std"))]
             Union::TimeStamp(_, _, _) => f.write_str("<timestamp>"),