Add scope command to repl.

examples/repl.rs

@@ -48,6 +48,7 @@ fn print_error(input: &str, err: EvalAltResult) {
 fn print_help() {
     println!("help       => print this help");
     println!("quit, exit => quit");
+    println!("scope      => print all variables in the scope");
     println!("ast        => print the last AST");
     println!("astu       => print the last raw, un-optimized AST");
     println!(r"end a line with '\' to continue to the next line.");
@@ -110,6 +111,13 @@ fn main() {
                 continue;
             }
             "exit" | "quit" => break, // quit
+            "scope" => {
+                scope
+                    .iter()
+                    .enumerate()
+                    .for_each(|(i, (name, value))| println!("[{}] {} = {:?}", i + 1, name, value));
+                continue;
+            }
             "astu" => {
                 // print the last un-optimized AST
                 println!("{:#?}", &ast_u);

src/scope.rs

@@ -444,9 +444,37 @@ impl<'a> Scope<'a> {
     }
 
     /// Get an iterator to entries in the Scope.
-    pub(crate) fn iter(&self) -> impl Iterator<Item = &Entry> {
+    pub(crate) fn to_iter(&self) -> impl Iterator<Item = &Entry> {
         self.0.iter().rev() // Always search a Scope in reverse order
     }
+
+    /// Get an iterator to entries in the Scope.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use rhai::{Dynamic, Scope};
+    ///
+    /// let mut my_scope = Scope::new();
+    ///
+    /// my_scope.push("x", 42_i64);
+    /// my_scope.push("foo", "hello".to_string());
+    ///
+    /// let mut iter = my_scope.iter();
+    ///
+    /// let (name, value) = iter.next().unwrap();
+    /// assert_eq!(name, "x");
+    /// assert_eq!(value.clone().cast::<i64>(), 42);
+    ///
+    /// let (name, value) = iter.next().unwrap();
+    /// assert_eq!(name, "foo");
+    /// assert_eq!(value.clone().cast::<String>(), "hello");
+    /// ```
+    pub fn iter(&self) -> impl Iterator<Item = (&str, &Dynamic)> {
+        self.0
+            .iter()
+            .map(|Entry { name, value, .. }| (name.as_ref(), value))
+    }
 }
 
 impl<'a, K: Into<Cow<'a, str>>> iter::Extend<(K, EntryType, Dynamic)> for Scope<'a> {