Use turbofish for impl Trait.

examples/event_handler_main/main.rs

@@ -124,7 +124,7 @@ pub fn main() {
                 let scope = &mut handler.scope;
                 let ast = &handler.ast;
 
-                let result: Result<(), _> = engine.call_fn(scope, ast, event, (arg.to_string(),));
+                let result = engine.call_fn::<()>(scope, ast, event, (arg.to_string(),));
 
                 if let Err(err) = result {
                     eprintln!("! {}", err)

examples/event_handler_map/main.rs

@@ -100,7 +100,7 @@ pub fn main() {
     println!();
 
     // Run the 'init' function to initialize the state, retaining variables.
-    let result: Result<(), _> = engine.call_fn(&mut scope, &ast, "init", ());
+    let result = engine.call_fn::<()>(&mut scope, &ast, "init", ());
 
     if let Err(err) = result {
         eprintln!("! {}", err)
@@ -138,7 +138,7 @@ pub fn main() {
                 let scope = &mut handler.scope;
                 let ast = &handler.ast;
 
-                let result: Result<(), _> = engine.call_fn(scope, ast, event, (arg.to_string(),));
+                let result = engine.call_fn::<()>(scope, ast, event, (arg.to_string(),));
 
                 if let Err(err) = result {
                     eprintln!("! {}", err)

src/api/call_fn.rs

@@ -41,14 +41,14 @@ impl Engine {
     /// scope.push("foo", 42_i64);
     ///
     /// // Call the script-defined function
-    /// let result: i64 = engine.call_fn(&mut scope, &ast, "add", ( "abc", 123_i64 ) )?;
+    /// let result = engine.call_fn::<i64>(&mut scope, &ast, "add", ( "abc", 123_i64 ) )?;
     /// assert_eq!(result, 168);
     ///
-    /// let result: i64 = engine.call_fn(&mut scope, &ast, "add1", ( "abc", ) )?;
+    /// let result = engine.call_fn::<i64>(&mut scope, &ast, "add1", ( "abc", ) )?;
     /// //                                                           ^^^^^^^^^^ tuple of one
     /// assert_eq!(result, 46);
     ///
-    /// let result: i64 = engine.call_fn(&mut scope, &ast, "bar", () )?;
+    /// let result = engine.call_fn::<i64>(&mut scope, &ast, "bar", () )?;
     /// assert_eq!(result, 21);
     /// # }
     /// # Ok(())

src/api/files.rs

@@ -6,12 +6,18 @@ use crate::types::dynamic::Variant;
 use crate::{Engine, RhaiResultOf, Scope, AST, ERR};
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
-use std::{fs::File, io::Read, path::PathBuf};
+use std::{
+    fs::File,
+    io::Read,
+    path::{Path, PathBuf},
+};
 
 impl Engine {
     /// Read the contents of a file into a string.
-    fn read_file(path: PathBuf) -> RhaiResultOf<String> {
+    fn read_file(path: impl AsRef<Path>) -> RhaiResultOf<String> {
-        let mut f = File::open(path.clone()).map_err(|err| {
+        let path = path.as_ref();
+
+        let mut f = File::open(path).map_err(|err| {
             ERR::ErrorSystem(
                 format!("Cannot open script file '{}'", path.to_string_lossy()),
                 err.into(),
@@ -214,7 +220,7 @@ impl Engine {
     }
 }
 
-/// Evaluate a script file.
+/// Evaluate a script file, returning the result value or an error.
 ///
 /// Not available under `no_std` or `WASM`.
 ///
@@ -222,13 +228,12 @@ impl Engine {
 ///
 /// ```no_run
 /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
-/// // Notice that a PathBuf is required which can easily be constructed from a string.
+/// let result = rhai::eval_file::<i64>("script.rhai")?;
-/// let result: i64 = rhai::eval_file("script.rhai".into())?;
 /// # Ok(())
 /// # }
 /// ```
 #[inline]
-pub fn eval_file<T: Variant + Clone>(path: PathBuf) -> RhaiResultOf<T> {
+pub fn eval_file<T: Variant + Clone>(path: impl AsRef<Path>) -> RhaiResultOf<T> {
     Engine::read_file(path).and_then(|contents| Engine::new().eval::<T>(&contents))
 }
 
@@ -240,16 +245,11 @@ pub fn eval_file<T: Variant + Clone>(path: PathBuf) -> RhaiResultOf<T> {
 ///
 /// ```no_run
 /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
-/// use rhai::Engine;
+/// rhai::run_file("script.rhai")?;
-///
-/// let engine = Engine::new();
-///
-/// // Notice that a PathBuf is required which can easily be constructed from a string.
-/// rhai::run_file("script.rhai".into())?;
 /// # Ok(())
 /// # }
 /// ```
 #[inline]
-pub fn run_file(path: PathBuf) -> RhaiResultOf<()> {
+pub fn run_file(path: impl AsRef<Path>) -> RhaiResultOf<()> {
     Engine::read_file(path).and_then(|contents| Engine::new().run(&contents))
 }

tests/call_fn.rs

@@ -29,13 +29,13 @@ fn test_call_fn() -> Result<(), Box<EvalAltResult>> {
         ",
     )?;
 
-    let r: INT = engine.call_fn(&mut scope, &ast, "hello", (42 as INT, 123 as INT))?;
+    let r = engine.call_fn::<INT>(&mut scope, &ast, "hello", (42 as INT, 123 as INT))?;
     assert_eq!(r, 165);
 
-    let r: INT = engine.call_fn(&mut scope, &ast, "hello", (123 as INT,))?;
+    let r = engine.call_fn::<INT>(&mut scope, &ast, "hello", (123 as INT,))?;
     assert_eq!(r, 5166);
 
-    let r: INT = engine.call_fn(&mut scope, &ast, "hello", ())?;
+    let r = engine.call_fn::<INT>(&mut scope, &ast, "hello", ())?;
     assert_eq!(r, 42);
 
     assert_eq!(
@@ -45,7 +45,7 @@ fn test_call_fn() -> Result<(), Box<EvalAltResult>> {
         1
     );
 
-    let r: INT = engine.call_fn(&mut scope, &ast, "define_var", (2 as INT,))?;
+    let r = engine.call_fn::<INT>(&mut scope, &ast, "define_var", (2 as INT,))?;
     assert_eq!(r, 42);
 
     assert!(!scope.contains("bar"));
@@ -132,7 +132,7 @@ fn test_call_fn_args() -> Result<(), Box<EvalAltResult>> {
         ",
     )?;
 
-    let result: String = engine.call_fn(&mut scope, &ast, "hello", options)?;
+    let result = engine.call_fn::<String>(&mut scope, &ast, "hello", options)?;
 
     assert_eq!(result, "world42");
 
@@ -146,12 +146,12 @@ fn test_call_fn_private() -> Result<(), Box<EvalAltResult>> {
 
     let ast = engine.compile("fn add(x, n) { x + n }")?;
 
-    let r: INT = engine.call_fn(&mut scope, &ast, "add", (40 as INT, 2 as INT))?;
+    let r = engine.call_fn::<INT>(&mut scope, &ast, "add", (40 as INT, 2 as INT))?;
     assert_eq!(r, 42);
 
     let ast = engine.compile("private fn add(x, n, ) { x + n }")?;
 
-    let r: INT = engine.call_fn(&mut scope, &ast, "add", (40 as INT, 2 as INT))?;
+    let r = engine.call_fn::<INT>(&mut scope, &ast, "add", (40 as INT, 2 as INT))?;
     assert_eq!(r, 42);
 
     Ok(())

tests/closures.rs

@@ -338,7 +338,7 @@ fn test_closures_shared_obj() -> Result<(), Box<EvalAltResult>> {
     let res = engine.eval_ast::<Map>(&ast)?;
 
     // Make closure
-    let f = move |p1: TestStruct, p2: TestStruct| -> Result<(), Box<EvalAltResult>> {
+    let f = move |p1: TestStruct, p2: TestStruct| {
         let action_ptr = res["action"].clone_cast::<FnPtr>();
         let name = action_ptr.fn_name();
         engine.call_fn(&mut Scope::new(), &ast, name, (p1, p2))

tests/modules.rs

@@ -279,7 +279,7 @@ fn test_module_resolver() -> Result<(), Box<EvalAltResult>> {
 
         assert!(engine.eval::<INT>(script).is_err());
 
-        let result: INT = engine.call_fn(&mut Scope::new(), &ast, "foo", (2 as INT,))?;
+        let result = engine.call_fn::<INT>(&mut Scope::new(), &ast, "foo", (2 as INT,))?;
 
         assert_eq!(result, 84);
 
@@ -296,7 +296,7 @@ fn test_module_resolver() -> Result<(), Box<EvalAltResult>> {
             assert_eq!(ast2.resolver().unwrap().len(), len);
         }
 
-        let result: INT = engine.call_fn(&mut Scope::new(), &ast2, "foo", (2 as INT,))?;
+        let result = engine.call_fn::<INT>(&mut Scope::new(), &ast2, "foo", (2 as INT,))?;
 
         assert_eq!(result, 84);
     }