diff --git a/Cargo.toml b/Cargo.toml
index b7580ea4..4ba4d03e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,7 @@
 [package]
 name = "rhai"
 version = "0.9.1"
+edition = "2018"
 authors = ["Jonathan Turner", "Lukáš Hozda"]
 description = "Embedded scripting for Rust"
 homepage = "https://github.com/jonathandturner/rhai"
diff --git a/README.md b/README.md
index 114746db..98f4d748 100644
--- a/README.md
+++ b/README.md
@@ -266,7 +266,7 @@ use rhai::{Engine, Scope};
 
 fn main() {
     let mut engine = Engine::new();
-    let mut scope: Scope = Vec::new();
+    let mut scope = Scope::new();
 
     if let Ok(_) = engine.eval_with_scope::<()>(&mut scope, "let x = 4 + 5") { } else { assert!(false); }
 
diff --git a/examples/arrays_and_structs.rs b/examples/arrays_and_structs.rs
index 987e177f..215abc8d 100644
--- a/examples/arrays_and_structs.rs
+++ b/examples/arrays_and_structs.rs
@@ -1,4 +1,3 @@
-extern crate rhai;
 use rhai::{Engine, RegisterFn};
 
 #[derive(Clone, Debug)]
@@ -24,6 +23,12 @@ fn main() {
     engine.register_fn("update", TestStruct::update);
     engine.register_fn("new_ts", TestStruct::new);
 
-    println!("{:?}", engine.eval::<TestStruct>("let x = new_ts(); x.update(); x"));
-    println!("{:?}", engine.eval::<TestStruct>("let x = [new_ts()]; x[0].update(); x[0]"));
+    println!(
+        "{:?}",
+        engine.eval::<TestStruct>("let x = new_ts(); x.update(); x")
+    );
+    println!(
+        "{:?}",
+        engine.eval::<TestStruct>("let x = [new_ts()]; x[0].update(); x[0]")
+    );
 }
diff --git a/examples/custom_types_and_methods.rs b/examples/custom_types_and_methods.rs
index 65cf3225..85cb2b60 100644
--- a/examples/custom_types_and_methods.rs
+++ b/examples/custom_types_and_methods.rs
@@ -1,4 +1,3 @@
-extern crate rhai;
 use rhai::{Engine, RegisterFn};
 
 #[derive(Clone)]
diff --git a/examples/hello.rs b/examples/hello.rs
index 925902b8..cb889fe5 100644
--- a/examples/hello.rs
+++ b/examples/hello.rs
@@ -1,4 +1,3 @@
-extern crate rhai;
 use rhai::Engine;
 
 fn main() {
diff --git a/examples/repl.rs b/examples/repl.rs
index 145c288b..8a75c3d5 100644
--- a/examples/repl.rs
+++ b/examples/repl.rs
@@ -1,9 +1,7 @@
-extern crate rhai;
-
-use std::fmt::Display;
-use std::process::exit;
-use std::io::{stdin, stdout, Write};
 use rhai::{Engine, RegisterFn, Scope};
+use std::fmt::Display;
+use std::io::{stdin, stdout, Write};
+use std::process::exit;
 
 fn showit<T: Display>(x: &mut T) -> () {
     println!("{}", x)
diff --git a/examples/reuse_scope.rs b/examples/reuse_scope.rs
index b01ec107..071eb9f3 100644
--- a/examples/reuse_scope.rs
+++ b/examples/reuse_scope.rs
@@ -1,11 +1,12 @@
-extern crate rhai;
 use rhai::{Engine, Scope};
 
 fn main() {
     let mut engine = Engine::new();
-    let mut scope: Scope = Vec::new();
+    let mut scope = Scope::new();
 
-    assert!(engine.eval_with_scope::<()>(&mut scope, "let x = 4 + 5").is_ok());
+    assert!(engine
+        .eval_with_scope::<()>(&mut scope, "let x = 4 + 5")
+        .is_ok());
 
     if let Ok(result) = engine.eval_with_scope::<i64>(&mut scope, "x") {
         println!("result: {}", result);
diff --git a/examples/rhai_runner.rs b/examples/rhai_runner.rs
index 6637844a..2e0da794 100644
--- a/examples/rhai_runner.rs
+++ b/examples/rhai_runner.rs
@@ -1,9 +1,7 @@
+use rhai::{Engine, RegisterFn};
 use std::env;
 use std::fmt::Display;
 
-extern crate rhai;
-use rhai::{Engine, RegisterFn};
-
 fn showit<T: Display>(x: &mut T) -> () {
     println!("{}", x)
 }
diff --git a/examples/simple_fn.rs b/examples/simple_fn.rs
index 04b55b68..ccef105e 100644
--- a/examples/simple_fn.rs
+++ b/examples/simple_fn.rs
@@ -1,4 +1,3 @@
-extern crate rhai;
 use rhai::{Engine, RegisterFn};
 
 fn add(x: i64, y: i64) -> i64 {
diff --git a/src/any.rs b/src/any.rs
index d0b3d8fb..ac2d9f68 100644
--- a/src/any.rs
+++ b/src/any.rs
@@ -4,7 +4,7 @@ use std::fmt;
 pub trait Any: StdAny {
     fn type_id(&self) -> TypeId;
 
-    fn box_clone(&self) -> Box<Any>;
+    fn box_clone(&self) -> Box<dyn Any>;
 
     /// This type may only be implemented by `rhai`.
     #[doc(hidden)]
@@ -12,8 +12,8 @@ pub trait Any: StdAny {
 }
 
 impl<T> Any for T
-    where
-        T: Clone + StdAny + ?Sized
+where
+    T: Clone + StdAny + ?Sized,
 {
     #[inline]
     fn type_id(&self) -> TypeId {
@@ -21,23 +21,24 @@ impl<T> Any for T
     }
 
     #[inline]
-    fn box_clone(&self) -> Box<Any> {
+    fn box_clone(&self) -> Box<dyn Any> {
         Box::new(self.clone())
     }
 
-    fn _closed(&self) -> _Private { _Private }
+    fn _closed(&self) -> _Private {
+        _Private
+    }
 }
 
-impl Any {
-    #[inline]
-    fn box_clone(&self) -> Box<Any> {
-        Any::box_clone(self)
-    }
-
+impl dyn Any {
+    //#[inline]
+    // fn box_clone(&self) -> Box<dyn Any> {
+    //     Any::box_clone(self)
+    // }
     #[inline]
     pub fn is<T: Any>(&self) -> bool {
         let t = TypeId::of::<T>();
-        let boxed = <Any as Any>::type_id(self);
+        let boxed = <dyn Any as Any>::type_id(self);
 
         t == boxed
     }
@@ -45,9 +46,7 @@ impl Any {
     #[inline]
     pub fn downcast_ref<T: Any>(&self) -> Option<&T> {
         if self.is::<T>() {
-            unsafe {
-                Some(&*(self as *const Any as *const T))
-            }
+            unsafe { Some(&*(self as *const dyn Any as *const T)) }
         } else {
             None
         }
@@ -56,23 +55,21 @@ impl Any {
     #[inline]
     pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T> {
         if self.is::<T>() {
-            unsafe {
-                Some(&mut *(self as *mut Any as *mut T))
-            }
+            unsafe { Some(&mut *(self as *mut dyn Any as *mut T)) }
         } else {
             None
         }
     }
 }
 
-impl Clone for Box<Any> {
+impl Clone for Box<dyn Any> {
     fn clone(&self) -> Self {
-        Any::box_clone(self.as_ref() as &Any)
+        Any::box_clone(self.as_ref() as &dyn Any)
     }
 }
 
-impl fmt::Debug for Any {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+impl fmt::Debug for dyn Any {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("Any")
     }
 }
@@ -81,11 +78,11 @@ pub trait AnyExt: Sized {
     fn downcast<T: Any + Clone>(self) -> Result<Box<T>, Self>;
 }
 
-impl AnyExt for Box<Any> {
+impl AnyExt for Box<dyn Any> {
     fn downcast<T: Any + Clone>(self) -> Result<Box<T>, Self> {
         if self.is::<T>() {
             unsafe {
-                let raw: *mut Any = Box::into_raw(self);
+                let raw: *mut dyn Any = Box::into_raw(self);
                 Ok(Box::from_raw(raw as *mut T))
             }
         } else {
diff --git a/src/call.rs b/src/call.rs
index cf3313e3..fa2439e9 100644
--- a/src/call.rs
+++ b/src/call.rs
@@ -1,10 +1,10 @@
 //! Helper module which defines `FnArgs`
 //! to make function calling easier.
 
-use any::Any;
+use crate::any::Any;
 
 pub trait FunArgs<'a> {
-    fn into_vec(self) -> Vec<&'a mut Any>;
+    fn into_vec(self) -> Vec<&'a mut dyn Any>;
 }
 
 macro_rules! impl_args {
@@ -13,11 +13,12 @@ macro_rules! impl_args {
         where
             $($p: Any + Clone),*
         {
-            fn into_vec(self) -> Vec<&'a mut Any> {
+            fn into_vec(self) -> Vec<&'a mut dyn Any> {
                 let ($($p,)*) = self;
 
+                #[allow(unused_variables, unused_mut)]
                 let mut v = Vec::new();
-                $(v.push($p as &mut Any);)*
+                $(v.push($p as &mut dyn Any);)*
 
                 v
             }
diff --git a/src/engine.rs b/src/engine.rs
index 4bff3753..1186afe1 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -1,16 +1,15 @@
 use std::any::TypeId;
-use std::borrow::Borrow;
 use std::cmp::{PartialEq, PartialOrd};
 use std::collections::HashMap;
 use std::error::Error;
 use std::fmt;
+use std::ops::{Add, BitAnd, BitOr, BitXor, Div, Mul, Neg, Rem, Shl, Shr, Sub};
 use std::sync::Arc;
-use std::ops::{Add, BitAnd, BitOr, BitXor, Deref, Div, Mul, Neg, Rem, Shl, Shr, Sub};
 
-use any::{Any, AnyExt};
-use fn_register::{Mut, RegisterFn};
-use parser::{lex, parse, Expr, FnDef, Stmt};
-use call::FunArgs;
+use crate::any::{Any, AnyExt};
+use crate::call::FunArgs;
+use crate::fn_register::RegisterFn;
+use crate::parser::{lex, parse, Expr, FnDef, Stmt};
 
 #[derive(Debug)]
 pub enum EvalAltResult {
@@ -26,7 +25,7 @@ pub enum EvalAltResult {
     ErrorCantOpenScriptFile,
     InternalErrorMalformedDotExpression,
     LoopBreak,
-    Return(Box<Any>),
+    Return(Box<dyn Any>),
 }
 
 impl EvalAltResult {
@@ -35,7 +34,7 @@ impl EvalAltResult {
             EvalAltResult::ErrorVariableNotFound(ref s) => Some(s.as_str()),
             EvalAltResult::ErrorFunctionNotFound(ref s) => Some(s.as_str()),
             EvalAltResult::ErrorMismatchOutputType(ref s) => Some(s.as_str()),
-            _ => None
+            _ => None,
         }
     }
 }
@@ -89,13 +88,13 @@ impl Error for EvalAltResult {
         }
     }
 
-    fn cause(&self) -> Option<&Error> {
+    fn cause(&self) -> Option<&dyn Error> {
         None
     }
 }
 
 impl fmt::Display for EvalAltResult {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let Some(s) = self.as_str() {
             write!(f, "{}: {}", self.description(), s)
         } else {
@@ -128,7 +127,7 @@ pub struct FnSpec {
 pub struct Engine {
     /// A hashmap containing all functions known to the engine
     pub fns: HashMap<FnSpec, Arc<FnIntExt>>,
-    pub type_names: HashMap<TypeId,String>,
+    pub type_names: HashMap<TypeId, String>,
 }
 
 pub enum FnIntExt {
@@ -136,7 +135,7 @@ pub enum FnIntExt {
     Int(FnDef),
 }
 
-pub type FnAny = Fn(Vec<&mut Any>) -> Result<Box<Any>, EvalAltResult>;
+pub type FnAny = dyn Fn(Vec<&mut dyn Any>) -> Result<Box<dyn Any>, EvalAltResult>;
 
 /// A type containing information about current scope.
 /// Useful for keeping state between `Engine` runs
@@ -152,7 +151,7 @@ pub type FnAny = Fn(Vec<&mut Any>) -> Result<Box<Any>, EvalAltResult>;
 /// ```
 ///
 /// Between runs, `Engine` only remembers functions when not using own `Scope`.
-pub type Scope = Vec<(String, Box<Any>)>;
+pub type Scope = Vec<(String, Box<dyn Any>)>;
 
 impl Engine {
     pub fn call_fn<'a, I, A, T>(&self, ident: I, args: A) -> Result<T, EvalAltResult>
@@ -174,8 +173,8 @@ impl Engine {
     pub fn call_fn_raw(
         &self,
         ident: String,
-        args: Vec<&mut Any>,
-    ) -> Result<Box<Any>, EvalAltResult> {
+        args: Vec<&mut dyn Any>,
+    ) -> Result<Box<dyn Any>, EvalAltResult> {
         debug_println!(
             "Trying to call function {:?} with args {:?}",
             ident,
@@ -184,17 +183,27 @@ impl Engine {
 
         let spec = FnSpec {
             ident: ident.clone(),
-            args: Some(args.iter().map(|a| <Any as Any>::type_id(&**a)).collect()),
+            args: Some(
+                args.iter()
+                    .map(|a| <dyn Any as Any>::type_id(&**a))
+                    .collect(),
+            ),
         };
 
         self.fns
             .get(&spec)
             .or_else(|| {
-                let spec1 = FnSpec { ident: ident.clone(), args: None };
+                let spec1 = FnSpec {
+                    ident: ident.clone(),
+                    args: None,
+                };
                 self.fns.get(&spec1)
             })
             .ok_or_else(|| {
-                let typenames = args.iter().map(|x| self.nice_type_name((&**x).box_clone())).collect::<Vec<_>>();
+                let typenames = args
+                    .iter()
+                    .map(|x| self.nice_type_name((&**x).box_clone()))
+                    .collect::<Vec<_>>();
                 EvalAltResult::ErrorFunctionNotFound(format!("{} ({})", ident, typenames.join(",")))
             })
             .and_then(move |f| match **f {
@@ -272,14 +281,15 @@ impl Engine {
     fn get_dot_val_helper(
         &self,
         scope: &mut Scope,
-        this_ptr: &mut Any,
+        this_ptr: &mut dyn Any,
         dot_rhs: &Expr,
-    ) -> Result<Box<Any>, EvalAltResult> {
+    ) -> Result<Box<dyn Any>, EvalAltResult> {
         use std::iter::once;
 
         match *dot_rhs {
             Expr::FnCall(ref fn_name, ref args) => {
-                let mut args: Vec<Box<Any>> = args.iter()
+                let mut args: Vec<Box<dyn Any>> = args
+                    .iter()
                     .map(|arg| self.eval_expr(scope, arg))
                     .collect::<Result<Vec<_>, _>>()?;
                 let args = once(this_ptr)
@@ -299,7 +309,7 @@ impl Engine {
 
                 let mut val = self.call_fn_raw(get_fn_name, vec![this_ptr])?;
 
-                ((*val).downcast_mut() as Option<&mut Vec<Box<Any>>>)
+                ((*val).downcast_mut() as Option<&mut Vec<Box<dyn Any>>>)
                     .and_then(|arr| idx.downcast_ref::<i64>().map(|idx| (arr, *idx as usize)))
                     .map(|(arr, idx)| arr[idx].clone())
                     .ok_or(EvalAltResult::ErrorIndexMismatch)
@@ -322,7 +332,7 @@ impl Engine {
         map: F,
     ) -> Result<(usize, T), EvalAltResult>
     where
-        F: FnOnce(&'a mut Any) -> Result<T, EvalAltResult>,
+        F: FnOnce(&'a mut dyn Any) -> Result<T, EvalAltResult>,
     {
         scope
             .iter_mut()
@@ -338,13 +348,14 @@ impl Engine {
         scope: &mut Scope,
         id: &str,
         idx: &Expr,
-    ) -> Result<(usize, usize, Box<Any>), EvalAltResult> {
-        let idx_boxed = self.eval_expr(scope, idx)?
+    ) -> Result<(usize, usize, Box<dyn Any>), EvalAltResult> {
+        let idx_boxed = self
+            .eval_expr(scope, idx)?
             .downcast::<i64>()
             .map_err(|_| EvalAltResult::ErrorIndexMismatch)?;
         let idx = *idx_boxed as usize;
         let (idx_sc, val) = Self::search_scope(scope, id, |val| {
-            ((*val).downcast_mut() as Option<&mut Vec<Box<Any>>>)
+            ((*val).downcast_mut() as Option<&mut Vec<Box<dyn Any>>>)
                 .map(|arr| arr[idx].clone())
                 .ok_or(EvalAltResult::ErrorIndexMismatch)
         })?;
@@ -357,7 +368,7 @@ impl Engine {
         scope: &mut Scope,
         dot_lhs: &Expr,
         dot_rhs: &Expr,
-    ) -> Result<Box<Any>, EvalAltResult> {
+    ) -> Result<Box<dyn Any>, EvalAltResult> {
         match *dot_lhs {
             Expr::Identifier(ref id) => {
                 let (sc_idx, mut target) = Self::search_scope(scope, id, |x| Ok(x.box_clone()))?;
@@ -375,7 +386,7 @@ impl Engine {
 
                 // In case the expression mutated `target`, we need to reassign it because
                 // of the above `clone`.
-                scope[sc_idx].1.downcast_mut::<Vec<Box<Any>>>().unwrap()[idx] = target;
+                scope[sc_idx].1.downcast_mut::<Vec<Box<dyn Any>>>().unwrap()[idx] = target;
 
                 value
             }
@@ -385,10 +396,10 @@ impl Engine {
 
     fn set_dot_val_helper(
         &self,
-        this_ptr: &mut Any,
+        this_ptr: &mut dyn Any,
         dot_rhs: &Expr,
-        mut source_val: Box<Any>,
-    ) -> Result<Box<Any>, EvalAltResult> {
+        mut source_val: Box<dyn Any>,
+    ) -> Result<Box<dyn Any>, EvalAltResult> {
         match *dot_rhs {
             Expr::Identifier(ref id) => {
                 let set_fn_name = "set$".to_string() + id;
@@ -419,8 +430,8 @@ impl Engine {
         scope: &mut Scope,
         dot_lhs: &Expr,
         dot_rhs: &Expr,
-        source_val: Box<Any>,
-    ) -> Result<Box<Any>, EvalAltResult> {
+        source_val: Box<dyn Any>,
+    ) -> Result<Box<dyn Any>, EvalAltResult> {
         match *dot_lhs {
             Expr::Identifier(ref id) => {
                 let (sc_idx, mut target) = Self::search_scope(scope, id, |x| Ok(x.box_clone()))?;
@@ -438,7 +449,7 @@ impl Engine {
 
                 // In case the expression mutated `target`, we need to reassign it because
                 // of the above `clone`.
-                scope[sc_idx].1.downcast_mut::<Vec<Box<Any>>>().unwrap()[idx] = target;
+                scope[sc_idx].1.downcast_mut::<Vec<Box<dyn Any>>>().unwrap()[idx] = target;
 
                 value
             }
@@ -446,7 +457,7 @@ impl Engine {
         }
     }
 
-    fn eval_expr(&self, scope: &mut Scope, expr: &Expr) -> Result<Box<Any>, EvalAltResult> {
+    fn eval_expr(&self, scope: &mut Scope, expr: &Expr) -> Result<Box<dyn Any>, EvalAltResult> {
         match *expr {
             Expr::IntConst(i) => Ok(Box::new(i)),
             Expr::FloatConst(i) => Ok(Box::new(i)),
@@ -484,7 +495,7 @@ impl Engine {
                             if *id == *name {
                                 if let Some(i) = idx.downcast_ref::<i64>() {
                                     if let Some(arr_typed) =
-                                        (*val).downcast_mut() as Option<&mut Vec<Box<Any>>>
+                                        (*val).downcast_mut() as Option<&mut Vec<Box<dyn Any>>>
                                     {
                                         arr_typed[*i as usize] = rhs_val;
                                         return Ok(Box::new(()));
@@ -520,7 +531,7 @@ impl Engine {
                 fn_name.to_owned(),
                 args.iter()
                     .map(|ex| self.eval_expr(scope, ex))
-                    .collect::<Result<Vec<Box<Any>>, _>>()?
+                    .collect::<Result<Vec<Box<dyn Any>>, _>>()?
                     .iter_mut()
                     .map(|b| b.as_mut())
                     .collect(),
@@ -531,12 +542,12 @@ impl Engine {
         }
     }
 
-    fn eval_stmt(&self, scope: &mut Scope, stmt: &Stmt) -> Result<Box<Any>, EvalAltResult> {
+    fn eval_stmt(&self, scope: &mut Scope, stmt: &Stmt) -> Result<Box<dyn Any>, EvalAltResult> {
         match *stmt {
             Stmt::Expr(ref e) => self.eval_expr(scope, e),
             Stmt::Block(ref b) => {
                 let prev_len = scope.len();
-                let mut last_result: Result<Box<Any>, EvalAltResult> = Ok(Box::new(()));
+                let mut last_result: Result<Box<dyn Any>, EvalAltResult> = Ok(Box::new(()));
 
                 for s in b.iter() {
                     last_result = self.eval_stmt(scope, s);
@@ -621,8 +632,8 @@ impl Engine {
         }
     }
 
-    fn nice_type_name(&self, b: Box<Any>) -> String {
-        let tid = <Any as Any>::type_id(&*b);
+    fn nice_type_name(&self, b: Box<dyn Any>) -> String {
+        let tid = <dyn Any as Any>::type_id(&*b);
         if let Some(name) = self.type_names.get(&tid) {
             name.to_string()
         } else {
@@ -650,7 +661,7 @@ impl Engine {
 
     /// Evaluate a string
     pub fn eval<T: Any + Clone>(&mut self, input: &str) -> Result<T, EvalAltResult> {
-        let mut scope: Scope = Vec::new();
+        let mut scope = Scope::new();
 
         self.eval_with_scope(&mut scope, input)
     }
@@ -668,7 +679,7 @@ impl Engine {
 
         match tree {
             Ok((ref os, ref fns)) => {
-                let mut x: Result<Box<Any>, EvalAltResult> = Ok(Box::new(()));
+                let mut x: Result<Box<dyn Any>, EvalAltResult> = Ok(Box::new(()));
 
                 for f in fns {
                     let name = f.name.clone();
@@ -693,7 +704,9 @@ impl Engine {
 
                 match x.downcast::<T>() {
                     Ok(out) => Ok(*out),
-                    Err(a) => Err(EvalAltResult::ErrorMismatchOutputType(self.nice_type_name(a))),
+                    Err(a) => Err(EvalAltResult::ErrorMismatchOutputType(
+                        self.nice_type_name(a),
+                    )),
                 }
             }
             Err(_) => Err(EvalAltResult::ErrorFunctionArgMismatch),
@@ -786,12 +799,12 @@ impl Engine {
         engine.register_type_name::<String>("string");
         engine.register_type_name::<char>("char");
         engine.register_type_name::<bool>("boolean");
-        engine.register_type_name::<Vec<Box<Any>>>("array");
+        engine.register_type_name::<Vec<Box<dyn Any>>>("array");
 
         macro_rules! reg_op {
             ($engine:expr, $x:expr, $op:expr, $( $y:ty ),*) => (
                 $(
-                    $engine.register_fn($x, ($op as fn(x: $y, y: $y)->$y));
+                    $engine.register_fn($x, $op as fn(x: $y, y: $y)->$y);
                 )*
             )
         }
@@ -799,7 +812,7 @@ impl Engine {
         macro_rules! reg_un {
             ($engine:expr, $x:expr, $op:expr, $( $y:ty ),*) => (
                 $(
-                    $engine.register_fn($x, ($op as fn(x: $y)->$y));
+                    $engine.register_fn($x, $op as fn(x: $y)->$y);
                 )*
             )
         }
@@ -807,36 +820,86 @@ impl Engine {
         macro_rules! reg_cmp {
             ($engine:expr, $x:expr, $op:expr, $( $y:ty ),*) => (
                 $(
-                    $engine.register_fn($x, ($op as fn(x: $y, y: $y)->bool));
+                    $engine.register_fn($x, $op as fn(x: $y, y: $y)->bool);
                 )*
             )
         }
 
-        fn add<T: Add>(x: T, y: T) -> <T as Add>::Output { x + y }
-        fn sub<T: Sub>(x: T, y: T) -> <T as Sub>::Output { x - y }
-        fn mul<T: Mul>(x: T, y: T) -> <T as Mul>::Output { x * y }
-        fn div<T: Div>(x: T, y: T) -> <T as Div>::Output { x / y }
-        fn neg<T: Neg>(x: T) -> <T as Neg>::Output       { -x }
-        fn lt<T: PartialOrd>(x: T, y: T) -> bool  { x < y  }
-        fn lte<T: PartialOrd>(x: T, y: T) -> bool { x <= y }
-        fn gt<T: PartialOrd>(x: T, y: T) -> bool  { x > y  }
-        fn gte<T: PartialOrd>(x: T, y: T) -> bool { x >= y }
-        fn eq<T: PartialEq>(x: T, y: T) -> bool   { x == y }
-        fn ne<T: PartialEq>(x: T, y: T) -> bool   { x != y }
-        fn and(x: bool, y: bool) -> bool { x && y }
-        fn or(x: bool, y: bool) -> bool  { x || y }
-        fn not(x: bool) -> bool { !x }
-        fn concat(x: String, y: String) -> String { x + &y }
-        fn binary_and<T: BitAnd>(x: T, y: T) -> <T as BitAnd>::Output  { x & y }
-        fn binary_or<T: BitOr>(x: T, y: T) -> <T as BitOr>::Output     { x | y }
-        fn binary_xor<T: BitXor>(x: T, y: T) -> <T as BitXor>::Output  { x ^ y }
-        fn left_shift<T: Shl<T>>(x: T, y: T) -> <T as Shl<T>>::Output  { x.shl(y) }
-        fn right_shift<T: Shr<T>>(x: T, y: T) -> <T as Shr<T>>::Output { x.shr(y) }
-        fn modulo<T: Rem<T>>(x: T, y: T) -> <T as Rem<T>>::Output { x % y }
-        fn pow_i64_i64(x: i64, y: i64) -> i64 { x.pow(y as u32) }
-        fn pow_f64_f64(x: f64, y: f64) -> f64 { x.powf(y) }
-        fn pow_f64_i64(x: f64, y: i64) -> f64 { x.powi(y as i32) }
-        fn unit_eq(a: (), b: ()) -> bool { true }
+        fn add<T: Add>(x: T, y: T) -> <T as Add>::Output {
+            x + y
+        }
+        fn sub<T: Sub>(x: T, y: T) -> <T as Sub>::Output {
+            x - y
+        }
+        fn mul<T: Mul>(x: T, y: T) -> <T as Mul>::Output {
+            x * y
+        }
+        fn div<T: Div>(x: T, y: T) -> <T as Div>::Output {
+            x / y
+        }
+        fn neg<T: Neg>(x: T) -> <T as Neg>::Output {
+            -x
+        }
+        fn lt<T: PartialOrd>(x: T, y: T) -> bool {
+            x < y
+        }
+        fn lte<T: PartialOrd>(x: T, y: T) -> bool {
+            x <= y
+        }
+        fn gt<T: PartialOrd>(x: T, y: T) -> bool {
+            x > y
+        }
+        fn gte<T: PartialOrd>(x: T, y: T) -> bool {
+            x >= y
+        }
+        fn eq<T: PartialEq>(x: T, y: T) -> bool {
+            x == y
+        }
+        fn ne<T: PartialEq>(x: T, y: T) -> bool {
+            x != y
+        }
+        fn and(x: bool, y: bool) -> bool {
+            x && y
+        }
+        fn or(x: bool, y: bool) -> bool {
+            x || y
+        }
+        fn not(x: bool) -> bool {
+            !x
+        }
+        fn concat(x: String, y: String) -> String {
+            x + &y
+        }
+        fn binary_and<T: BitAnd>(x: T, y: T) -> <T as BitAnd>::Output {
+            x & y
+        }
+        fn binary_or<T: BitOr>(x: T, y: T) -> <T as BitOr>::Output {
+            x | y
+        }
+        fn binary_xor<T: BitXor>(x: T, y: T) -> <T as BitXor>::Output {
+            x ^ y
+        }
+        fn left_shift<T: Shl<T>>(x: T, y: T) -> <T as Shl<T>>::Output {
+            x.shl(y)
+        }
+        fn right_shift<T: Shr<T>>(x: T, y: T) -> <T as Shr<T>>::Output {
+            x.shr(y)
+        }
+        fn modulo<T: Rem<T>>(x: T, y: T) -> <T as Rem<T>>::Output {
+            x % y
+        }
+        fn pow_i64_i64(x: i64, y: i64) -> i64 {
+            x.pow(y as u32)
+        }
+        fn pow_f64_f64(x: f64, y: f64) -> f64 {
+            x.powf(y)
+        }
+        fn pow_f64_i64(x: f64, y: i64) -> f64 {
+            x.powi(y as i32)
+        }
+        fn unit_eq(_a: (), _b: ()) -> bool {
+            true
+        }
 
         reg_op!(engine, "+", add, i32, i64, u32, u64, f32, f64);
         reg_op!(engine, "-", sub, i32, i64, u32, u64, f32, f64);
@@ -874,7 +937,6 @@ impl Engine {
         // FIXME?  Registering array lookups are a special case because we want to return boxes
         // directly let ent = engine.fns.entry("[]".to_string()).or_insert_with(Vec::new);
         // (*ent).push(FnType::ExternalFn2(Box::new(idx)));
-
     }
 
     /// Make a new engine
diff --git a/src/fn_register.rs b/src/fn_register.rs
index ad4fbe03..0dcf6fe4 100644
--- a/src/fn_register.rs
+++ b/src/fn_register.rs
@@ -1,7 +1,7 @@
 use std::any::TypeId;
 
-use any::Any;
-use engine::{Engine, EvalAltResult};
+use crate::any::Any;
+use crate::engine::{Engine, EvalAltResult};
 
 pub trait RegisterFn<FN, ARGS, RET> {
     fn register_fn(&mut self, name: &str, f: FN);
@@ -27,13 +27,14 @@ macro_rules! def_register {
             RET: Any,
         {
             fn register_fn(&mut self, name: &str, f: FN) {
-                let fun = move |mut args: Vec<&mut Any>| {
+                let fun = move |mut args: Vec<&mut dyn Any>| {
                     // Check for length at the beginning to avoid
                     // per-element bound checks.
                     if args.len() != count_args!($($par)*) {
                         return Err(EvalAltResult::ErrorFunctionArgMismatch);
                     }
 
+                    #[allow(unused_variables, unused_mut)]
                     let mut drain = args.drain(..);
                     $(
                     // Downcast every element, return in case of a type mismatch
@@ -43,7 +44,7 @@ macro_rules! def_register {
 
                     // Call the user-supplied function using ($clone) to
                     // potentially clone the value, otherwise pass the reference.
-                    Ok(Box::new(f($(($clone)($par)),*)) as Box<Any>)
+                    Ok(Box::new(f($(($clone)($par)),*)) as Box<dyn Any>)
                 };
                 self.register_fn_raw(name.to_owned(), Some(vec![$(TypeId::of::<$par>()),*]), Box::new(fun));
             }
diff --git a/src/lib.rs b/src/lib.rs
index a012216e..6aa339bd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -30,9 +30,7 @@
 //!
 //! [Check out the README on GitHub for more information!](https://github.com/jonathandturner/rhai)
 
-// lints required by Rhai
-#![allow(warnings, unknown_lints, type_complexity, new_without_default_derive,
-         needless_pass_by_value, too_many_arguments)]
+#![allow(non_snake_case)]
 
 // needs to be here, because order matters for macros
 macro_rules! debug_println {
@@ -50,4 +48,3 @@ mod parser;
 pub use any::Any;
 pub use engine::{Engine, EvalAltResult, Scope};
 pub use fn_register::RegisterFn;
-
diff --git a/src/parser.rs b/src/parser.rs
index 34ed60f4..0e82f0f4 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,8 +1,8 @@
+use std::char;
 use std::error::Error;
 use std::fmt;
 use std::iter::Peekable;
 use std::str::Chars;
-use std::char;
 
 #[derive(Debug, Clone)]
 pub enum LexError {
@@ -10,7 +10,7 @@ pub enum LexError {
     MalformedEscapeSequence,
     MalformedNumber,
     MalformedChar,
-    Nothing
+    Nothing,
 }
 
 impl Error for LexError {
@@ -20,13 +20,13 @@ impl Error for LexError {
             LexError::MalformedEscapeSequence => "Unexpected values in escape sequence",
             LexError::MalformedNumber => "Unexpected characters in number",
             LexError::MalformedChar => "Char constant not a single character",
-            LexError::Nothing => "This error is for internal use only"
+            LexError::Nothing => "This error is for internal use only",
         }
     }
 }
 
 impl fmt::Display for LexError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{}", self.description())
     }
 }
@@ -65,11 +65,13 @@ impl Error for ParseError {
         }
     }
 
-    fn cause(&self) -> Option<&Error> { None }
+    fn cause(&self) -> Option<&dyn Error> {
+        None
+    }
 }
 
 impl fmt::Display for ParseError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{}", self.description())
     }
 }
@@ -268,11 +270,7 @@ impl Token {
         use self::Token::*;
 
         match *self {
-            UnaryPlus        |
-            UnaryMinus       |
-            Equals           |
-            Bang             |
-            Return => true,
+            UnaryPlus | UnaryMinus | Equals | Bang | Return => true,
             _ => false,
         }
     }
@@ -390,14 +388,14 @@ impl<'a> TokenIterator<'a> {
     fn inner_next(&mut self) -> Option<Token> {
         while let Some(c) = self.char_stream.next() {
             match c {
-                '0'...'9' => {
+                '0'..='9' => {
                     let mut result = Vec::new();
                     let mut radix_base: Option<u32> = None;
                     result.push(c);
 
                     while let Some(&nxt) = self.char_stream.peek() {
                         match nxt {
-                            '0'...'9' => {
+                            '0'..='9' => {
                                 result.push(nxt);
                                 self.char_stream.next();
                             }
@@ -406,7 +404,7 @@ impl<'a> TokenIterator<'a> {
                                 self.char_stream.next();
                                 while let Some(&nxt_float) = self.char_stream.peek() {
                                     match nxt_float {
-                                        '0'...'9' => {
+                                        '0'..='9' => {
                                             result.push(nxt_float);
                                             self.char_stream.next();
                                         }
@@ -419,7 +417,7 @@ impl<'a> TokenIterator<'a> {
                                 self.char_stream.next();
                                 while let Some(&nxt_hex) = self.char_stream.peek() {
                                     match nxt_hex {
-                                        '0'...'9' | 'a'...'f' | 'A'...'F' => {
+                                        '0'..='9' | 'a'..='f' | 'A'..='F' => {
                                             result.push(nxt_hex);
                                             self.char_stream.next();
                                         }
@@ -433,7 +431,7 @@ impl<'a> TokenIterator<'a> {
                                 self.char_stream.next();
                                 while let Some(&nxt_oct) = self.char_stream.peek() {
                                     match nxt_oct {
-                                        '0'...'8' => {
+                                        '0'..='8' => {
                                             result.push(nxt_oct);
                                             self.char_stream.next();
                                         }
@@ -461,7 +459,12 @@ impl<'a> TokenIterator<'a> {
                     }
 
                     if let Some(radix) = radix_base {
-                        let out: String = result.iter().cloned().skip(2).filter(|c| c != &'_').collect();
+                        let out: String = result
+                            .iter()
+                            .cloned()
+                            .skip(2)
+                            .filter(|c| c != &'_')
+                            .collect();
                         if let Ok(val) = i64::from_str_radix(&out, radix) {
                             return Some(Token::IntConst(val));
                         }
@@ -476,7 +479,7 @@ impl<'a> TokenIterator<'a> {
                     }
                     return Some(Token::LexErr(LexError::MalformedNumber));
                 }
-                'A'...'Z' | 'a'...'z' | '_' => {
+                'A'..='Z' | 'a'..='z' | '_' => {
                     let mut result = Vec::new();
                     result.push(c);
 
@@ -505,30 +508,26 @@ impl<'a> TokenIterator<'a> {
                         x => return Some(Token::Identifier(x.to_string())),
                     }
                 }
-                '"' => {
-                    match self.parse_string_const('"') {
-                        Ok(out) => return Some(Token::StringConst(out)),
-                        Err(e) => return Some(Token::LexErr(e)),
-                    }
-                }
-                '\'' => {
-                    match self.parse_string_const('\'') {
-                        Ok(result) => {
-                            let mut chars = result.chars();
+                '"' => match self.parse_string_const('"') {
+                    Ok(out) => return Some(Token::StringConst(out)),
+                    Err(e) => return Some(Token::LexErr(e)),
+                },
+                '\'' => match self.parse_string_const('\'') {
+                    Ok(result) => {
+                        let mut chars = result.chars();
 
-                            if let Some(out) = chars.next() {
-                                println!("result: {}", result);
-                                if chars.count() != 0 {
-                                    return Some(Token::LexErr(LexError::MalformedChar));
-                                }
-                                return Some(Token::CharConst(out));
-                            } else {
+                        if let Some(out) = chars.next() {
+                            println!("result: {}", result);
+                            if chars.count() != 0 {
                                 return Some(Token::LexErr(LexError::MalformedChar));
                             }
+                            return Some(Token::CharConst(out));
+                        } else {
+                            return Some(Token::LexErr(LexError::MalformedChar));
                         }
-                        Err(e) => return Some(Token::LexErr(e)),
                     }
-                }
+                    Err(e) => return Some(Token::LexErr(e)),
+                },
                 '{' => return Some(Token::LCurly),
                 '}' => return Some(Token::RCurly),
                 '(' => return Some(Token::LParen),
@@ -540,182 +539,168 @@ impl<'a> TokenIterator<'a> {
                         Some(&'=') => {
                             self.char_stream.next();
                             Some(Token::PlusAssign)
-                        },
+                        }
                         _ if self.last.is_next_unary() => Some(Token::UnaryPlus),
                         _ => Some(Token::Plus),
                     }
-                },
+                }
                 '-' => {
                     return match self.char_stream.peek() {
                         Some(&'=') => {
                             self.char_stream.next();
                             Some(Token::MinusAssign)
-                        },
+                        }
                         _ if self.last.is_next_unary() => Some(Token::UnaryMinus),
                         _ => Some(Token::Minus),
                     }
-                },
+                }
                 '*' => {
                     return match self.char_stream.peek() {
                         Some(&'=') => {
                             self.char_stream.next();
                             Some(Token::MultiplyAssign)
-                        },
-                        _ => Some(Token::Multiply)
-                    }
-                },
-                '/' => {
-                    match self.char_stream.peek() {
-                        Some(&'/') => {
-                            self.char_stream.next();
-                            while let Some(c) = self.char_stream.next() {
-                                if c == '\n' { break; }
-                            }
                         }
-                        Some(&'*') => {
-                            let mut level = 1;
-                            self.char_stream.next();
-                            while let Some(c) = self.char_stream.next() {
-                                match c {
-                                    '/' => if let Some('*') = self.char_stream.next() {
-                                        level+=1;
-                                    }
-                                    '*' => if let Some('/') = self.char_stream.next() {
-                                        level-=1;
-                                    }
-                                    _ => (),
-                                }
-
-                                if level == 0 {
-                                    break;
-                                }
-                            }
-                        }
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::DivideAssign);
-                        }
-                        _ => return Some(Token::Divide),
+                        _ => Some(Token::Multiply),
                     }
                 }
+                '/' => match self.char_stream.peek() {
+                    Some(&'/') => {
+                        self.char_stream.next();
+                        while let Some(c) = self.char_stream.next() {
+                            if c == '\n' {
+                                break;
+                            }
+                        }
+                    }
+                    Some(&'*') => {
+                        let mut level = 1;
+                        self.char_stream.next();
+                        while let Some(c) = self.char_stream.next() {
+                            match c {
+                                '/' => {
+                                    if let Some('*') = self.char_stream.next() {
+                                        level += 1;
+                                    }
+                                }
+                                '*' => {
+                                    if let Some('/') = self.char_stream.next() {
+                                        level -= 1;
+                                    }
+                                }
+                                _ => (),
+                            }
+
+                            if level == 0 {
+                                break;
+                            }
+                        }
+                    }
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::DivideAssign);
+                    }
+                    _ => return Some(Token::Divide),
+                },
                 ';' => return Some(Token::Semicolon),
                 ':' => return Some(Token::Colon),
                 ',' => return Some(Token::Comma),
                 '.' => return Some(Token::Period),
-                '=' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::EqualTo);
-                        }
-                        _ => return Some(Token::Equals),
-                    }
-                }
-                '<' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::LessThanEqual);
-                        }
-                        Some(&'<') => {
-                            self.char_stream.next();
-                            return match self.char_stream.peek() {
-                                Some(&'=') => {
-                                    self.char_stream.next();
-                                    Some(Token::LeftShiftAssign)
-                                },
-                                _ => {
-                                    self.char_stream.next();
-                                    Some(Token::LeftShift)
-                                }
-                            }
-                        }
-                        _ => return Some(Token::LessThan),
-                    }
-                }
-                '>' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::GreaterThanEqual);
-                        }
-                        Some(&'>') => {
-                            self.char_stream.next();
-                            return match self.char_stream.peek() {
-                                Some(&'=') => {
-                                    self.char_stream.next();
-                                    Some(Token::RightShiftAssign)
-                                },
-                                _ => {
-                                    self.char_stream.next();
-                                    Some(Token::RightShift)
-                                }
-                            }
-                        }
-                        _ => return Some(Token::GreaterThan),
-                    }
-                }
-                '!' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::NotEqualTo);
-                        }
-                        _ => return Some(Token::Bang),
-                    }
-                }
-                '|' => {
-                    match self.char_stream.peek() {
-                        Some(&'|') => {
-                            self.char_stream.next();
-                            return Some(Token::Or);
-                        }
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::OrAssign);
-                        }
-                        _ => return Some(Token::Pipe),
-                    }
-                }
-                '&' => {
-                    match self.char_stream.peek() {
-                        Some(&'&') => {
-                            self.char_stream.next();
-                            return Some(Token::And);
-                        }
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::AndAssign);
-                        }
-                        _ => return Some(Token::Ampersand),
-                    }
-                }
-                '^' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::XOrAssign);
-                        }
-                        _ => return Some(Token::XOr)
+                '=' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::EqualTo);
                     }
+                    _ => return Some(Token::Equals),
                 },
-                '%' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::ModuloAssign);
-                        }
-                        _ => return Some(Token::Modulo)
+                '<' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::LessThanEqual);
                     }
+                    Some(&'<') => {
+                        self.char_stream.next();
+                        return match self.char_stream.peek() {
+                            Some(&'=') => {
+                                self.char_stream.next();
+                                Some(Token::LeftShiftAssign)
+                            }
+                            _ => {
+                                self.char_stream.next();
+                                Some(Token::LeftShift)
+                            }
+                        };
+                    }
+                    _ => return Some(Token::LessThan),
                 },
-                '~' => {
-                    match self.char_stream.peek() {
-                        Some(&'=') => {
-                            self.char_stream.next();
-                            return Some(Token::PowerOfAssign);
-                        }
-                        _ => return Some(Token::PowerOf)
+                '>' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::GreaterThanEqual);
                     }
+                    Some(&'>') => {
+                        self.char_stream.next();
+                        return match self.char_stream.peek() {
+                            Some(&'=') => {
+                                self.char_stream.next();
+                                Some(Token::RightShiftAssign)
+                            }
+                            _ => {
+                                self.char_stream.next();
+                                Some(Token::RightShift)
+                            }
+                        };
+                    }
+                    _ => return Some(Token::GreaterThan),
+                },
+                '!' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::NotEqualTo);
+                    }
+                    _ => return Some(Token::Bang),
+                },
+                '|' => match self.char_stream.peek() {
+                    Some(&'|') => {
+                        self.char_stream.next();
+                        return Some(Token::Or);
+                    }
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::OrAssign);
+                    }
+                    _ => return Some(Token::Pipe),
+                },
+                '&' => match self.char_stream.peek() {
+                    Some(&'&') => {
+                        self.char_stream.next();
+                        return Some(Token::And);
+                    }
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::AndAssign);
+                    }
+                    _ => return Some(Token::Ampersand),
+                },
+                '^' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::XOrAssign);
+                    }
+                    _ => return Some(Token::XOr),
+                },
+                '%' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::ModuloAssign);
+                    }
+                    _ => return Some(Token::Modulo),
+                },
+                '~' => match self.char_stream.peek() {
+                    Some(&'=') => {
+                        self.char_stream.next();
+                        return Some(Token::PowerOfAssign);
+                    }
+                    _ => return Some(Token::PowerOf),
                 },
                 _x if _x.is_whitespace() => (),
                 _ => return Some(Token::LexErr(LexError::UnexpectedChar)),
@@ -739,8 +724,11 @@ impl<'a> Iterator for TokenIterator<'a> {
     }
 }
 
-pub fn lex(input: &str) -> TokenIterator {
-    TokenIterator { last: Token::LexErr(LexError::Nothing), char_stream: input.chars().peekable() }
+pub fn lex(input: &str) -> TokenIterator<'_> {
+    TokenIterator {
+        last: Token::LexErr(LexError::Nothing),
+        char_stream: input.chars().peekable(),
+    }
 }
 
 fn get_precedence(token: &Token) -> i32 {
@@ -757,24 +745,17 @@ fn get_precedence(token: &Token) -> i32 {
         | Token::XOrAssign
         | Token::ModuloAssign
         | Token::PowerOfAssign => 10,
-        Token::Or
-        | Token::XOr
-        | Token::Pipe  => 11,
-        Token::And
-        | Token::Ampersand => 12,
+        Token::Or | Token::XOr | Token::Pipe => 11,
+        Token::And | Token::Ampersand => 12,
         Token::LessThan
         | Token::LessThanEqual
         | Token::GreaterThan
         | Token::GreaterThanEqual
         | Token::EqualTo
         | Token::NotEqualTo => 15,
-        Token::Plus
-        | Token::Minus => 20,
-        Token::Divide
-        | Token::Multiply
-        | Token::PowerOf => 40,
-        Token::LeftShift
-        | Token::RightShift => 50,
+        Token::Plus | Token::Minus => 20,
+        Token::Divide | Token::Multiply | Token::PowerOf => 40,
+        Token::LeftShift | Token::RightShift => 50,
         Token::Modulo => 60,
         Token::Period => 100,
         _ => -1,
@@ -782,7 +763,7 @@ fn get_precedence(token: &Token) -> i32 {
 }
 
 fn parse_paren_expr<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr, ParseError> {
-    let expr = try!(parse_expr(input));
+    let expr = parse_expr(input)?;
 
     match input.next() {
         Some(Token::RParen) => Ok(expr),
@@ -790,9 +771,10 @@ fn parse_paren_expr<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr,
     }
 }
 
-fn parse_call_expr<'a>(id: String,
-                       input: &mut Peekable<TokenIterator<'a>>)
-                       -> Result<Expr, ParseError> {
+fn parse_call_expr<'a>(
+    id: String,
+    input: &mut Peekable<TokenIterator<'a>>,
+) -> Result<Expr, ParseError> {
     let mut args = Vec::new();
 
     if let Some(&Token::RParen) = input.peek() {
@@ -820,9 +802,10 @@ fn parse_call_expr<'a>(id: String,
     }
 }
 
-fn parse_index_expr<'a>(id: String,
-                        input: &mut Peekable<TokenIterator<'a>>)
-                        -> Result<Expr, ParseError> {
+fn parse_index_expr<'a>(
+    id: String,
+    input: &mut Peekable<TokenIterator<'a>>,
+) -> Result<Expr, ParseError> {
     if let Ok(idx) = parse_expr(input) {
         match input.peek() {
             Some(&Token::RSquare) => {
@@ -836,9 +819,10 @@ fn parse_index_expr<'a>(id: String,
     }
 }
 
-fn parse_ident_expr<'a>(id: String,
-                        input: &mut Peekable<TokenIterator<'a>>)
-                        -> Result<Expr, ParseError> {
+fn parse_ident_expr<'a>(
+    id: String,
+    input: &mut Peekable<TokenIterator<'a>>,
+) -> Result<Expr, ParseError> {
     match input.peek() {
         Some(&Token::LParen) => {
             input.next();
@@ -862,12 +846,14 @@ fn parse_array_expr<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr,
 
     if !skip_contents {
         while let Some(_) = input.peek() {
-            arr.push(try!(parse_expr(input)));
+            arr.push(parse_expr(input)?);
             if let Some(&Token::Comma) = input.peek() {
                 input.next();
             }
 
-            if let Some(&Token::RSquare) = input.peek() { break }
+            if let Some(&Token::RSquare) = input.peek() {
+                break;
+            }
         }
     }
 
@@ -878,7 +864,6 @@ fn parse_array_expr<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr,
         }
         _ => Err(ParseError::MissingRSquare),
     }
-
 }
 
 fn parse_primary<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr, ParseError> {
@@ -914,17 +899,27 @@ fn parse_unary<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr, Pars
     };
 
     match tok {
-        Token::UnaryMinus => { input.next(); Ok(Expr::FnCall("-".to_string(), vec![parse_primary(input)?])) }
-        Token::UnaryPlus => { input.next(); parse_primary(input) }
-        Token::Bang => { input.next(); Ok(Expr::FnCall("!".to_string(), vec![parse_primary(input)?])) }
-        _ => parse_primary(input)
+        Token::UnaryMinus => {
+            input.next();
+            Ok(Expr::FnCall("-".to_string(), vec![parse_primary(input)?]))
+        }
+        Token::UnaryPlus => {
+            input.next();
+            parse_primary(input)
+        }
+        Token::Bang => {
+            input.next();
+            Ok(Expr::FnCall("!".to_string(), vec![parse_primary(input)?]))
+        }
+        _ => parse_primary(input),
     }
 }
 
-fn parse_binop<'a>(input: &mut Peekable<TokenIterator<'a>>,
-                   prec: i32,
-                   lhs: Expr)
-                   -> Result<Expr, ParseError> {
+fn parse_binop<'a>(
+    input: &mut Peekable<TokenIterator<'a>>,
+    prec: i32,
+    lhs: Expr,
+) -> Result<Expr, ParseError> {
     let mut lhs_curr = lhs;
 
     loop {
@@ -939,7 +934,7 @@ fn parse_binop<'a>(input: &mut Peekable<TokenIterator<'a>>,
         }
 
         if let Some(op_token) = input.next() {
-            let mut rhs = try!(parse_unary(input));
+            let mut rhs = parse_unary(input)?;
 
             let mut next_prec = -1;
 
@@ -948,10 +943,10 @@ fn parse_binop<'a>(input: &mut Peekable<TokenIterator<'a>>,
             }
 
             if curr_prec < next_prec {
-                rhs = try!(parse_binop(input, curr_prec + 1, rhs));
+                rhs = parse_binop(input, curr_prec + 1, rhs)?;
             } else if curr_prec >= 100 {
                 // Always bind right to left for precedence over 100
-                rhs = try!(parse_binop(input, curr_prec, rhs));
+                rhs = parse_binop(input, curr_prec, rhs)?;
             }
 
             lhs_curr = match op_token {
@@ -960,31 +955,27 @@ fn parse_binop<'a>(input: &mut Peekable<TokenIterator<'a>>,
                 Token::Multiply => Expr::FnCall("*".to_string(), vec![lhs_curr, rhs]),
                 Token::Divide => Expr::FnCall("/".to_string(), vec![lhs_curr, rhs]),
                 Token::Equals => Expr::Assignment(Box::new(lhs_curr), Box::new(rhs)),
-                Token::PlusAssign  => {
+                Token::PlusAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("+".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("+".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
-                Token::MinusAssign  => {
+                }
+                Token::MinusAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("-".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("-".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::Period => Expr::Dot(Box::new(lhs_curr), Box::new(rhs)),
                 Token::EqualTo => Expr::FnCall("==".to_string(), vec![lhs_curr, rhs]),
                 Token::NotEqualTo => Expr::FnCall("!=".to_string(), vec![lhs_curr, rhs]),
                 Token::LessThan => Expr::FnCall("<".to_string(), vec![lhs_curr, rhs]),
-                Token::LessThanEqual => {
-                    Expr::FnCall("<=".to_string(), vec![lhs_curr, rhs])
-                }
+                Token::LessThanEqual => Expr::FnCall("<=".to_string(), vec![lhs_curr, rhs]),
                 Token::GreaterThan => Expr::FnCall(">".to_string(), vec![lhs_curr, rhs]),
-                Token::GreaterThanEqual => {
-                    Expr::FnCall(">=".to_string(), vec![lhs_curr, rhs])
-                }
+                Token::GreaterThanEqual => Expr::FnCall(">=".to_string(), vec![lhs_curr, rhs]),
                 Token::Or => Expr::FnCall("||".to_string(), vec![lhs_curr, rhs]),
                 Token::And => Expr::FnCall("&&".to_string(), vec![lhs_curr, rhs]),
                 Token::XOr => Expr::FnCall("^".to_string(), vec![lhs_curr, rhs]),
@@ -992,73 +983,71 @@ fn parse_binop<'a>(input: &mut Peekable<TokenIterator<'a>>,
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("|".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("|".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::AndAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("&".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("&".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::XOrAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("^".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("^".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::MultiplyAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("*".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("*".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::DivideAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("/".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("/".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
-                Token::Pipe => {
-                    Expr::FnCall("|".to_string(), vec![lhs_curr, rhs])
-                },
+                }
+                Token::Pipe => Expr::FnCall("|".to_string(), vec![lhs_curr, rhs]),
                 Token::LeftShift => Expr::FnCall("<<".to_string(), vec![lhs_curr, rhs]),
                 Token::RightShift => Expr::FnCall(">>".to_string(), vec![lhs_curr, rhs]),
                 Token::LeftShiftAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("<<".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("<<".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::RightShiftAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall(">>".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall(">>".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::Ampersand => Expr::FnCall("&".to_string(), vec![lhs_curr, rhs]),
                 Token::Modulo => Expr::FnCall("%".to_string(), vec![lhs_curr, rhs]),
                 Token::ModuloAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("%".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("%".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 Token::PowerOf => Expr::FnCall("~".to_string(), vec![lhs_curr, rhs]),
                 Token::PowerOfAssign => {
                     let lhs_copy = lhs_curr.clone();
                     Expr::Assignment(
                         Box::new(lhs_curr),
-                        Box::new(Expr::FnCall("~".to_string(), vec![lhs_copy, rhs]))
+                        Box::new(Expr::FnCall("~".to_string(), vec![lhs_copy, rhs])),
                     )
-                },
+                }
                 _ => return Err(ParseError::UnknownOperator),
             };
         }
@@ -1069,7 +1058,7 @@ fn parse_expr<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr, Parse
     match input.peek() {
         Some(Token::RParen) => Ok(Expr::Unit),
         _ => {
-            let lhs = try!(parse_unary(input));
+            let lhs = parse_unary(input)?;
 
             parse_binop(input, 0, lhs)
         }
@@ -1079,14 +1068,18 @@ fn parse_expr<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Expr, Parse
 fn parse_if<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, ParseError> {
     input.next();
 
-    let guard = try!(parse_expr(input));
-    let body = try!(parse_block(input));
+    let guard = parse_expr(input)?;
+    let body = parse_block(input)?;
 
     match input.peek() {
         Some(&Token::Else) => {
             input.next();
-            let else_body = try!(parse_block(input));
-            Ok(Stmt::IfElse(Box::new(guard), Box::new(body), Box::new(else_body)))
+            let else_body = parse_block(input)?;
+            Ok(Stmt::IfElse(
+                Box::new(guard),
+                Box::new(body),
+                Box::new(else_body),
+            ))
         }
         _ => Ok(Stmt::If(Box::new(guard), Box::new(body))),
     }
@@ -1095,8 +1088,8 @@ fn parse_if<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, ParseEr
 fn parse_while<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, ParseError> {
     input.next();
 
-    let guard = try!(parse_expr(input));
-    let body = try!(parse_block(input));
+    let guard = parse_expr(input)?;
+    let body = parse_block(input)?;
 
     Ok(Stmt::While(Box::new(guard), Box::new(body)))
 }
@@ -1104,7 +1097,7 @@ fn parse_while<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, Pars
 fn parse_loop<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, ParseError> {
     input.next();
 
-    let body = try!(parse_block(input));
+    let body = parse_block(input)?;
 
     Ok(Stmt::Loop(Box::new(body)))
 }
@@ -1120,7 +1113,7 @@ fn parse_var<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, ParseE
     match input.peek() {
         Some(&Token::Equals) => {
             input.next();
-            let initializer = try!(parse_expr(input));
+            let initializer = parse_expr(input)?;
             Ok(Stmt::Var(name, Some(Box::new(initializer))))
         }
         _ => Ok(Stmt::Var(name, None)),
@@ -1144,13 +1137,15 @@ fn parse_block<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, Pars
 
     if !skip_body {
         while let Some(_) = input.peek() {
-            stmts.push(try!(parse_stmt(input)));
+            stmts.push(parse_stmt(input)?);
 
             if let Some(&Token::Semicolon) = input.peek() {
                 input.next();
             }
 
-            if let Some(&Token::RCurly) = input.peek() { break }
+            if let Some(&Token::RCurly) = input.peek() {
+                break;
+            }
         }
     }
 
@@ -1164,7 +1159,7 @@ fn parse_block<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, Pars
 }
 
 fn parse_expr_stmt<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, ParseError> {
-    let expr = try!(parse_expr(input));
+    let expr = parse_expr(input)?;
     Ok(Stmt::Expr(Box::new(expr)))
 }
 
@@ -1182,7 +1177,7 @@ fn parse_stmt<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<Stmt, Parse
             match input.peek() {
                 Some(&Token::Semicolon) => Ok(Stmt::Return),
                 _ => {
-                    let ret = try!(parse_expr(input));
+                    let ret = parse_expr(input)?;
                     Ok(Stmt::ReturnWithVal(Box::new(ret)))
                 }
             }
@@ -1240,15 +1235,16 @@ fn parse_fn<'a>(input: &mut Peekable<TokenIterator<'a>>) -> Result<FnDef, ParseE
     })
 }
 
-fn parse_top_level<'a>(input: &mut Peekable<TokenIterator<'a>>)
-                       -> Result<(Vec<Stmt>, Vec<FnDef>), ParseError> {
+fn parse_top_level<'a>(
+    input: &mut Peekable<TokenIterator<'a>>,
+) -> Result<(Vec<Stmt>, Vec<FnDef>), ParseError> {
     let mut stmts = Vec::new();
     let mut fndefs = Vec::new();
 
     while let Some(_) = input.peek() {
         match input.peek() {
-            Some(&Token::Fn) => fndefs.push(try!(parse_fn(input))),
-            _ => stmts.push(try!(parse_stmt(input))),
+            Some(&Token::Fn) => fndefs.push(parse_fn(input)?),
+            _ => stmts.push(parse_stmt(input)?),
         }
 
         if let Some(&Token::Semicolon) = input.peek() {
@@ -1259,7 +1255,8 @@ fn parse_top_level<'a>(input: &mut Peekable<TokenIterator<'a>>)
     Ok((stmts, fndefs))
 }
 
-pub fn parse<'a>(input: &mut Peekable<TokenIterator<'a>>)
-                 -> Result<(Vec<Stmt>, Vec<FnDef>), ParseError> {
+pub fn parse<'a>(
+    input: &mut Peekable<TokenIterator<'a>>,
+) -> Result<(Vec<Stmt>, Vec<FnDef>), ParseError> {
     parse_top_level(input)
 }
diff --git a/tests/arrays.rs b/tests/arrays.rs
index 37a4e823..2845678a 100644
--- a/tests/arrays.rs
+++ b/tests/arrays.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 use rhai::RegisterFn;
 
@@ -59,8 +57,10 @@ fn test_array_with_structs() {
         assert!(false);
     }
 
-    if let Ok(result) = engine.eval::<i64>("let a = [new_ts()]; a[0].x = 100; a[0].update(); \
-                                            a[0].x") {
+    if let Ok(result) = engine.eval::<i64>(
+        "let a = [new_ts()]; a[0].x = 100; a[0].update(); \
+         a[0].x",
+    ) {
         assert_eq!(result, 1100);
     } else {
         assert!(false);
diff --git a/tests/binary_ops.rs b/tests/binary_ops.rs
index a9cb58e2..611f12d2 100644
--- a/tests/binary_ops.rs
+++ b/tests/binary_ops.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/bit_shift.rs b/tests/bit_shift.rs
index c35de15d..c0043082 100644
--- a/tests/bit_shift.rs
+++ b/tests/bit_shift.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/bool_op.rs b/tests/bool_op.rs
index a9ecf84b..4803cf18 100644
--- a/tests/bool_op.rs
+++ b/tests/bool_op.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/chars.rs b/tests/chars.rs
index 7e0100fe..7352b203 100644
--- a/tests/chars.rs
+++ b/tests/chars.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/comments.rs b/tests/comments.rs
index 48d25c1b..0b871944 100644
--- a/tests/comments.rs
+++ b/tests/comments.rs
@@ -1,12 +1,14 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
 fn test_comments() {
-	let mut engine = Engine::new();
+    let mut engine = Engine::new();
 
-	assert!(engine.eval::<i64>("let x = 5; x // I am a single line comment, yay!").is_ok());
+    assert!(engine
+        .eval::<i64>("let x = 5; x // I am a single line comment, yay!")
+        .is_ok());
 
-	assert!(engine.eval::<i64>("let /* I am a multiline comment, yay! */ x = 5; x").is_ok());
+    assert!(engine
+        .eval::<i64>("let /* I am a multiline comment, yay! */ x = 5; x")
+        .is_ok());
 }
diff --git a/tests/compound_equality.rs b/tests/compound_equality.rs
index dc8cc3ed..096756f0 100644
--- a/tests/compound_equality.rs
+++ b/tests/compound_equality.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/decrement.rs b/tests/decrement.rs
index 87bb8c1f..874e2675 100644
--- a/tests/decrement.rs
+++ b/tests/decrement.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/float.rs b/tests/float.rs
index eb4003c7..87fd19f1 100644
--- a/tests/float.rs
+++ b/tests/float.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 use rhai::RegisterFn;
 
diff --git a/tests/get_set.rs b/tests/get_set.rs
index 58076fca..8e76bc27 100644
--- a/tests/get_set.rs
+++ b/tests/get_set.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 use rhai::RegisterFn;
 
@@ -74,7 +72,9 @@ fn test_big_get_set() {
         }
 
         fn new() -> TestParent {
-            TestParent { child: TestChild::new() }
+            TestParent {
+                child: TestChild::new(),
+            }
         }
     }
 
@@ -88,5 +88,8 @@ fn test_big_get_set() {
 
     engine.register_fn("new_tp", TestParent::new);
 
-    assert_eq!(engine.eval::<i64>("let a = new_tp(); a.child.x = 500; a.child.x"), Ok(500));
+    assert_eq!(
+        engine.eval::<i64>("let a = new_tp(); a.child.x = 500; a.child.x"),
+        Ok(500)
+    );
 }
diff --git a/tests/if_block.rs b/tests/if_block.rs
index 4202940f..c6de6c8d 100644
--- a/tests/if_block.rs
+++ b/tests/if_block.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/increment.rs b/tests/increment.rs
index 3dc4593b..3c541802 100644
--- a/tests/increment.rs
+++ b/tests/increment.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/internal_fn.rs b/tests/internal_fn.rs
index 5dcb37f6..48409635 100644
--- a/tests/internal_fn.rs
+++ b/tests/internal_fn.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
@@ -23,8 +21,10 @@ fn test_internal_fn() {
 fn test_big_internal_fn() {
     let mut engine = Engine::new();
 
-    if let Ok(result) = engine.eval::<i64>("fn mathme(a, b, c, d, e, f) { a - b * c + d * e - f \
-                                            } mathme(100, 5, 2, 9, 6, 32)") {
+    if let Ok(result) = engine.eval::<i64>(
+        "fn mathme(a, b, c, d, e, f) { a - b * c + d * e - f \
+         } mathme(100, 5, 2, 9, 6, 32)",
+    ) {
         assert_eq!(result, 112);
     } else {
         assert!(false);
diff --git a/tests/looping.rs b/tests/looping.rs
index 76990dcc..4359df16 100644
--- a/tests/looping.rs
+++ b/tests/looping.rs
@@ -1,13 +1,12 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
 fn test_loop() {
-	let mut engine = Engine::new();
+    let mut engine = Engine::new();
 
-	assert!(
-		engine.eval::<bool>("
+    assert!(engine
+        .eval::<bool>(
+            "
 			let x = 0;
 			let i = 0;
 
@@ -22,6 +21,7 @@ fn test_loop() {
 			}
 
 			x == 45
-		").unwrap()
-	)
+		"
+        )
+        .unwrap())
 }
diff --git a/tests/method_call.rs b/tests/method_call.rs
index 9208459d..ee6b3dc0 100644
--- a/tests/method_call.rs
+++ b/tests/method_call.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 use rhai::RegisterFn;
 
@@ -32,5 +30,4 @@ fn test_method_call() {
     } else {
         assert!(false);
     }
-
 }
diff --git a/tests/mismatched_op.rs b/tests/mismatched_op.rs
index ef35e3a3..0c455d99 100644
--- a/tests/mismatched_op.rs
+++ b/tests/mismatched_op.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::{Engine, EvalAltResult};
 
 #[test]
@@ -8,6 +6,8 @@ fn test_mismatched_op() {
 
     assert_eq!(
         engine.eval::<i64>("60 + \"hello\""),
-        Err(EvalAltResult::ErrorFunctionNotFound("+ (integer,string)".into()))
+        Err(EvalAltResult::ErrorFunctionNotFound(
+            "+ (integer,string)".into()
+        ))
     );
 }
diff --git a/tests/not.rs b/tests/not.rs
index 81c0d217..9a7cafba 100644
--- a/tests/not.rs
+++ b/tests/not.rs
@@ -1,15 +1,21 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
 fn test_not() {
-	let mut engine = Engine::new();
+    let mut engine = Engine::new();
 
-	assert_eq!(engine.eval::<bool>("let not_true = !true; not_true").unwrap(), false);
+    assert_eq!(
+        engine
+            .eval::<bool>("let not_true = !true; not_true")
+            .unwrap(),
+        false
+    );
 
-	assert_eq!(engine.eval::<bool>("fn not(x) { !x } not(false)").unwrap(), true);
+    assert_eq!(
+        engine.eval::<bool>("fn not(x) { !x } not(false)").unwrap(),
+        true
+    );
 
-	// TODO - do we allow stacking unary operators directly? e.g '!!!!!!!true'
-	assert_eq!(engine.eval::<bool>("!(!(!(!(true))))").unwrap(), true)
+    // TODO - do we allow stacking unary operators directly? e.g '!!!!!!!true'
+    assert_eq!(engine.eval::<bool>("!(!(!(!(true))))").unwrap(), true)
 }
diff --git a/tests/number_literals.rs b/tests/number_literals.rs
index 7f9a0cbe..4e5e3d09 100644
--- a/tests/number_literals.rs
+++ b/tests/number_literals.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/ops.rs b/tests/ops.rs
index 5d30580a..ceb5e6fe 100644
--- a/tests/ops.rs
+++ b/tests/ops.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/power_of.rs b/tests/power_of.rs
index 14d6a030..bcac45df 100644
--- a/tests/power_of.rs
+++ b/tests/power_of.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
@@ -8,7 +6,10 @@ fn test_power_of() {
 
     assert_eq!(engine.eval::<i64>("2 ~ 3").unwrap(), 8);
     assert_eq!(engine.eval::<i64>("(-2 ~ 3)").unwrap(), -8);
-    assert_eq!(engine.eval::<f64>("2.2 ~ 3.3").unwrap(), 13.489468760533386_f64);
+    assert_eq!(
+        engine.eval::<f64>("2.2 ~ 3.3").unwrap(),
+        13.489468760533386_f64
+    );
     assert_eq!(engine.eval::<f64>("2.0~-2.0").unwrap(), 0.25_f64);
     assert_eq!(engine.eval::<f64>("(-2.0~-2.0)").unwrap(), 0.25_f64);
     assert_eq!(engine.eval::<f64>("(-2.0~-2)").unwrap(), 0.25_f64);
@@ -21,9 +22,21 @@ fn test_power_of_equals() {
 
     assert_eq!(engine.eval::<i64>("let x = 2; x ~= 3; x").unwrap(), 8);
     assert_eq!(engine.eval::<i64>("let x = -2; x ~= 3; x").unwrap(), -8);
-    assert_eq!(engine.eval::<f64>("let x = 2.2; x ~= 3.3; x").unwrap(), 13.489468760533386_f64);
-    assert_eq!(engine.eval::<f64>("let x = 2.0; x ~= -2.0; x").unwrap(), 0.25_f64);
-    assert_eq!(engine.eval::<f64>("let x = -2.0; x ~= -2.0; x").unwrap(), 0.25_f64);
-    assert_eq!(engine.eval::<f64>("let x = -2.0; x ~= -2; x").unwrap(), 0.25_f64);
+    assert_eq!(
+        engine.eval::<f64>("let x = 2.2; x ~= 3.3; x").unwrap(),
+        13.489468760533386_f64
+    );
+    assert_eq!(
+        engine.eval::<f64>("let x = 2.0; x ~= -2.0; x").unwrap(),
+        0.25_f64
+    );
+    assert_eq!(
+        engine.eval::<f64>("let x = -2.0; x ~= -2.0; x").unwrap(),
+        0.25_f64
+    );
+    assert_eq!(
+        engine.eval::<f64>("let x = -2.0; x ~= -2; x").unwrap(),
+        0.25_f64
+    );
     assert_eq!(engine.eval::<i64>("let x =4; x ~= 3; x").unwrap(), 64);
 }
diff --git a/tests/string.rs b/tests/string.rs
index 975b7adc..26f97441 100644
--- a/tests/string.rs
+++ b/tests/string.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/unary_after_binary.rs b/tests/unary_after_binary.rs
index 848ff2c3..0a1cc169 100644
--- a/tests/unary_after_binary.rs
+++ b/tests/unary_after_binary.rs
@@ -1,12 +1,9 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
 // TODO also add test case for unary after compound
 // Hah, turns out unary + has a good use after all!
-fn test_unary_after_binary()
-{
+fn test_unary_after_binary() {
     let mut engine = Engine::new();
 
     if let Ok(result) = engine.eval::<i64>("10 % +4") {
diff --git a/tests/unary_minus.rs b/tests/unary_minus.rs
index 0306067f..21f49ad4 100644
--- a/tests/unary_minus.rs
+++ b/tests/unary_minus.rs
@@ -1,14 +1,12 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
 fn test_unary_minus() {
-	let mut engine = Engine::new();
+    let mut engine = Engine::new();
 
-	assert_eq!(engine.eval::<i64>("let x = -5; x").unwrap(), -5);
+    assert_eq!(engine.eval::<i64>("let x = -5; x").unwrap(), -5);
 
-	assert_eq!(engine.eval::<i64>("fn n(x) { -x } n(5)").unwrap(), -5);
+    assert_eq!(engine.eval::<i64>("fn n(x) { -x } n(5)").unwrap(), -5);
 
-	assert_eq!(engine.eval::<i64>("5 - -(-5)").unwrap(), 0);
+    assert_eq!(engine.eval::<i64>("5 - -(-5)").unwrap(), 0);
 }
diff --git a/tests/unit.rs b/tests/unit.rs
index ad2aff08..0f8fda65 100644
--- a/tests/unit.rs
+++ b/tests/unit.rs
@@ -1,5 +1,3 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
diff --git a/tests/var_scope.rs b/tests/var_scope.rs
index 0243671d..c32cd07d 100644
--- a/tests/var_scope.rs
+++ b/tests/var_scope.rs
@@ -1,11 +1,9 @@
-extern crate rhai;
-
 use rhai::{Engine, Scope};
 
 #[test]
 fn test_var_scope() {
     let mut engine = Engine::new();
-    let mut scope: Scope = Vec::new();
+    let mut scope = Scope::new();
 
     if let Ok(_) = engine.eval_with_scope::<()>(&mut scope, "let x = 4 + 5") {
     } else {
diff --git a/tests/while_loop.rs b/tests/while_loop.rs
index c34d72d3..464ff982 100644
--- a/tests/while_loop.rs
+++ b/tests/while_loop.rs
@@ -1,13 +1,13 @@
-extern crate rhai;
-
 use rhai::Engine;
 
 #[test]
 fn test_while() {
     let mut engine = Engine::new();
 
-    if let Ok(result) = engine.eval::<i64>("let x = 0; while x < 10 { x = x + 1; if x > 5 { \
-                                            break } } x") {
+    if let Ok(result) = engine.eval::<i64>(
+        "let x = 0; while x < 10 { x = x + 1; if x > 5 { \
+         break } } x",
+    ) {
         assert_eq!(result, 6);
     } else {
         assert!(false);