Merge branch 'master' into plugins

README.md

@@ -1947,7 +1947,7 @@ Properties and methods in a Rust custom type registered with the [`Engine`] can
 ```rust
 let a = new_ts();           // constructor function
 a.field = 500;              // property access
-a.update();                 // method call
+a.update();                 // method call, 'a' can be changed
 
 update(a);                  // this works, but 'a' is unchanged because only
                             // a COPY of 'a' is passed to 'update' by VALUE

benches/eval_array.rs

@@ -51,7 +51,7 @@ fn bench_eval_array_large_set(bench: &mut Bencher) {
     let script = r#"let x = [ 1, 2.345, "hello", true,
                                 [ 1, 2, 3, [ "hey", [ "deeply", "nested" ], "jude" ] ]
                             ];
-                            x[4] = 42
+                            x[4][3][1][1] = 42
     "#;
 
     let mut engine = Engine::new();

scripts/mat_mul.rhai

@@ -16,9 +16,7 @@ fn mat_gen(n) {
 
     for i in range(0, n) {
         for j in range(0, n) {
-			let foo = m[i];
+            m[i][j] = tmp * (i.to_float() - j.to_float()) * (i.to_float() + j.to_float());
-            foo[j] = tmp * (i.to_float() - j.to_float()) * (i.to_float() + j.to_float());
-			m[i] = foo;
         }
     }
 	
@@ -34,9 +32,7 @@ fn mat_mul(a, b) {
 	
     for i in range(0, n) {
         for j in range(0, p) {
-			let foo = b2[j];
+            b2[j][i] = b[i][j];
-            foo[i] = b[i][j];
-			b2[j] = foo;
         }
     }
 

scripts/primes.rhai

@@ -2,7 +2,7 @@
 
 let now = timestamp();
 
-const MAX_NUMBER_TO_CHECK = 10_000;     // 1229 primes <= 10000
+const MAX_NUMBER_TO_CHECK = 100_000;     // 9592 primes <= 100000
 
 let prime_mask = [];
 prime_mask.pad(MAX_NUMBER_TO_CHECK, true);

src/any.rs

@@ -212,7 +212,7 @@ impl fmt::Display for Dynamic {
             #[cfg(not(feature = "no_float"))]
             Union::Float(value) => write!(f, "{}", value),
             Union::Array(value) => write!(f, "{:?}", value),
-            Union::Map(value) => write!(f, "{:?}", value),
+            Union::Map(value) => write!(f, "#{:?}", value),
             Union::Variant(_) => write!(f, "?"),
         }
     }
@@ -229,7 +229,7 @@ impl fmt::Debug for Dynamic {
             #[cfg(not(feature = "no_float"))]
             Union::Float(value) => write!(f, "{:?}", value),
             Union::Array(value) => write!(f, "{:?}", value),
-            Union::Map(value) => write!(f, "{:?}", value),
+            Union::Map(value) => write!(f, "#{:?}", value),
             Union::Variant(_) => write!(f, "<dynamic>"),
         }
     }
@@ -268,16 +268,6 @@ fn cast_box<X: Variant, T: Variant>(item: Box<X>) -> Result<T, Box<X>> {
 }
 
 impl Dynamic {
-    /// Get a reference to the inner `Union`.
-    pub(crate) fn get_ref(&self) -> &Union {
-        &self.0
-    }
-
-    /// Get a mutable reference to the inner `Union`.
-    pub(crate) fn get_mut(&mut self) -> &mut Union {
-        &mut self.0
-    }
-
     /// Create a `Dynamic` from any type.  A `Dynamic` value is simply returned as is.
     ///
     /// Beware that you need to pass in an `Array` type for it to be recognized as an `Array`.

src/api.rs

@@ -146,14 +146,8 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_object"))]
     pub fn register_type_with_name<T: Variant + Clone>(&mut self, name: &str) {
-        if self.type_names.is_none() {
-            self.type_names = Some(HashMap::new());
-        }
-
         // Add the pretty-print type name into the map
         self.type_names
-            .as_mut()
-            .unwrap()
             .insert(type_name::<T>().to_string(), name.to_string());
     }
 
@@ -804,7 +798,7 @@ impl Engine {
         ast.0
             .iter()
             .try_fold(().into(), |_, stmt| {
-                self.eval_stmt(scope, Some(ast.1.as_ref()), stmt, 0)
+                self.eval_stmt(scope, ast.1.as_ref(), stmt, 0)
             })
             .or_else(|err| match *err {
                 EvalAltResult::Return(out, _) => Ok(out),
@@ -867,7 +861,7 @@ impl Engine {
         ast.0
             .iter()
             .try_fold(().into(), |_, stmt| {
-                self.eval_stmt(scope, Some(ast.1.as_ref()), stmt, 0)
+                self.eval_stmt(scope, ast.1.as_ref(), stmt, 0)
             })
             .map_or_else(
                 |err| match *err {
@@ -930,8 +924,7 @@ impl Engine {
             .get_function(name, args.len())
             .ok_or_else(|| Box::new(EvalAltResult::ErrorFunctionNotFound(name.to_string(), pos)))?;
 
-        let result =
+        let result = self.call_fn_from_lib(Some(scope), fn_lib, fn_def, &mut args, pos, 0)?;
-            self.call_fn_from_lib(Some(scope), Some(&fn_lib), fn_def, &mut args, pos, 0)?;
 
         let return_type = self.map_type_name(result.type_name());
 
@@ -995,7 +988,7 @@ impl Engine {
     /// ```
     #[cfg(feature = "sync")]
     pub fn on_print(&mut self, callback: impl Fn(&str) + Send + Sync + 'static) {
-        self.on_print = Some(Box::new(callback));
+        self.print = Box::new(callback);
     }
     /// Override default action of `print` (print to stdout using `println!`)
     ///
@@ -1023,7 +1016,7 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "sync"))]
     pub fn on_print(&mut self, callback: impl Fn(&str) + 'static) {
-        self.on_print = Some(Box::new(callback));
+        self.print = Box::new(callback);
     }
 
     /// Override default action of `debug` (print to stdout using `println!`)
@@ -1052,7 +1045,7 @@ impl Engine {
     /// ```
     #[cfg(feature = "sync")]
     pub fn on_debug(&mut self, callback: impl Fn(&str) + Send + Sync + 'static) {
-        self.on_debug = Some(Box::new(callback));
+        self.debug = Box::new(callback);
     }
     /// Override default action of `debug` (print to stdout using `println!`)
     ///
@@ -1080,6 +1073,6 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "sync"))]
     pub fn on_debug(&mut self, callback: impl Fn(&str) + 'static) {
-        self.on_debug = Some(Box::new(callback));
+        self.debug = Box::new(callback);
     }
 }

src/error.rs

@@ -100,8 +100,6 @@ pub enum ParseErrorType {
     FnMissingBody(String),
     /// Assignment to an inappropriate LHS (left-hand-side) expression.
     AssignmentToInvalidLHS,
-    /// Assignment to a copy of a value.
-    AssignmentToCopy,
     /// Assignment to an a constant variable.
     AssignmentToConstant(String),
     /// Break statement not inside a loop.
@@ -150,7 +148,6 @@ impl ParseError {
             ParseErrorType::FnMissingBody(_) => "Expecting body statement block for function declaration",
             ParseErrorType::WrongFnDefinition => "Function definitions must be at global level and cannot be inside a block or another function",
             ParseErrorType::AssignmentToInvalidLHS => "Cannot assign to this expression",
-            ParseErrorType::AssignmentToCopy => "Cannot assign to this expression because it will only be changing a copy of the value",
             ParseErrorType::AssignmentToConstant(_) => "Cannot assign to a constant variable.",
             ParseErrorType::LoopBreak => "Break statement should only be used inside a loop"
         }

src/optimize.rs

@@ -646,12 +646,12 @@ fn optimize<'a>(
         .filter(|ScopeEntry { typ, expr, .. }| {
             // Get all the constants with definite constant expressions
             *typ == ScopeEntryType::Constant
-                && expr.as_ref().map(Expr::is_constant).unwrap_or(false)
+                && expr.as_ref().map(|v| v.is_constant()).unwrap_or(false)
         })
         .for_each(|ScopeEntry { name, expr, .. }| {
             state.push_constant(
                 name.as_ref(),
-                expr.as_ref().expect("should be Some(expr)").clone(),
+                (**expr.as_ref().expect("should be Some(expr)")).clone(),
             )
         });
 

src/packages/map_basic.rs

@@ -12,12 +12,10 @@ use crate::stdlib::{
 };
 
 fn map_get_keys(map: &mut Map) -> Vec<Dynamic> {
-    map.iter()
+    map.iter().map(|(k, _)| k.to_string().into()).collect()
-        .map(|(k, _)| k.to_string().into())
-        .collect::<Vec<_>>()
 }
 fn map_get_values(map: &mut Map) -> Vec<Dynamic> {
-    map.iter().map(|(_, v)| v.clone()).collect::<Vec<_>>()
+    map.iter().map(|(_, v)| v.clone()).collect()
 }
 
 #[cfg(not(feature = "no_object"))]

src/packages/string_more.rs

@@ -37,7 +37,7 @@ fn sub_string(s: &mut String, start: INT, len: INT) -> String {
         len as usize
     };
 
-    chars[offset..][..len].into_iter().collect::<String>()
+    chars[offset..][..len].into_iter().collect()
 }
 fn crop_string(s: &mut String, start: INT, len: INT) {
     let offset = if s.is_empty() || len <= 0 {

src/packages/time_basic.rs

@@ -87,10 +87,10 @@ def_package!(crate:BasicTimePackage:"Basic timing utilities.", lib, {
                 #[cfg(not(feature = "unchecked"))]
                 {
                     if seconds > (MAX_INT as u64) {
-                        return Err(EvalAltResult::ErrorArithmetic(
+                        return Err(Box::new(EvalAltResult::ErrorArithmetic(
                             format!("Integer overflow for timestamp.elapsed(): {}", seconds),
                             Position::none(),
-                        ));
+                        )));
                     }
                 }
                 return Ok(seconds as INT);

src/parser.rs

@@ -476,34 +476,42 @@ impl Expr {
     /// Is a particular token allowed as a postfix operator to this expression?
     pub fn is_valid_postfix(&self, token: &Token) -> bool {
         match self {
-            Expr::IntegerConstant(_, _)
+            Self::IntegerConstant(_, _)
-            | Expr::FloatConstant(_, _)
+            | Self::FloatConstant(_, _)
-            | Expr::CharConstant(_, _)
+            | Self::CharConstant(_, _)
-            | Expr::In(_, _, _)
+            | Self::In(_, _, _)
-            | Expr::And(_, _, _)
+            | Self::And(_, _, _)
-            | Expr::Or(_, _, _)
+            | Self::Or(_, _, _)
-            | Expr::True(_)
+            | Self::True(_)
-            | Expr::False(_)
+            | Self::False(_)
-            | Expr::Unit(_) => false,
+            | Self::Unit(_) => false,
 
-            Expr::StringConstant(_, _)
+            Self::StringConstant(_, _)
-            | Expr::Stmt(_, _)
+            | Self::Stmt(_, _)
-            | Expr::FunctionCall(_, _, _, _)
+            | Self::FunctionCall(_, _, _, _)
-            | Expr::Assignment(_, _, _)
+            | Self::Assignment(_, _, _)
-            | Expr::Dot(_, _, _)
+            | Self::Dot(_, _, _)
-            | Expr::Index(_, _, _)
+            | Self::Index(_, _, _)
-            | Expr::Array(_, _)
+            | Self::Array(_, _)
-            | Expr::Map(_, _) => match token {
+            | Self::Map(_, _) => match token {
                 Token::LeftBracket => true,
                 _ => false,
             },
 
-            Expr::Variable(_, _) | Expr::Property(_, _) => match token {
+            Self::Variable(_, _) | Self::Property(_, _) => match token {
                 Token::LeftBracket | Token::LeftParen => true,
                 _ => false,
             },
         }
     }
+
+    /// Convert a `Variable` into a `Property`.  All other variants are untouched.
+    pub(crate) fn into_property(self) -> Self {
+        match self {
+            Self::Variable(id, pos) => Self::Property(id, pos),
+            _ => self,
+        }
+    }
 }
 
 /// Consume a particular token, checking that it is the expected one.
@@ -619,9 +627,10 @@ fn parse_call_expr<'a, S: Into<Cow<'static, str>> + Display>(
     }
 }
 
-/// Parse an indexing expression.
+/// Parse an indexing chain.
-fn parse_index_expr<'a>(
+/// Indexing binds to the right, so this call parses all possible levels of indexing following in the input.
-    lhs: Box<Expr>,
+fn parse_index_chain<'a>(
+    lhs: Expr,
     input: &mut Peekable<TokenIterator<'a>>,
     pos: Position,
     allow_stmt_expr: bool,
@@ -638,7 +647,7 @@ fn parse_index_expr<'a>(
             ))
             .into_err(*pos))
         }
-        Expr::IntegerConstant(_, pos) => match *lhs {
+        Expr::IntegerConstant(_, pos) => match lhs {
             Expr::Array(_, _) | Expr::StringConstant(_, _) => (),
 
             Expr::Map(_, _) => {
@@ -667,7 +676,7 @@ fn parse_index_expr<'a>(
         },
 
         // lhs[string]
-        Expr::StringConstant(_, pos) => match *lhs {
+        Expr::StringConstant(_, pos) => match lhs {
             Expr::Map(_, _) => (),
 
             Expr::Array(_, _) | Expr::StringConstant(_, _) => {
@@ -734,7 +743,20 @@ fn parse_index_expr<'a>(
     match input.peek().unwrap() {
         (Token::RightBracket, _) => {
             eat_token(input, Token::RightBracket);
-            Ok(Expr::Index(lhs, Box::new(idx_expr), pos))
+
+            // Any more indexing following?
+            match input.peek().unwrap() {
+                // If another indexing level, right-bind it
+                (Token::LeftBracket, _) => {
+                    let follow_pos = eat_token(input, Token::LeftBracket);
+                    // Recursively parse the indexing chain, right-binding each
+                    let follow = parse_index_chain(idx_expr, input, follow_pos, allow_stmt_expr)?;
+                    // Indexing binds to right
+                    Ok(Expr::Index(Box::new(lhs), Box::new(follow), pos))
+                }
+                // Otherwise terminate the indexing chain
+                _ => Ok(Expr::Index(Box::new(lhs), Box::new(idx_expr), pos)),
+            }
         }
         (Token::LexError(err), pos) => return Err(PERR::BadInput(err.to_string()).into_err(*pos)),
         (_, pos) => Err(PERR::MissingToken(
@@ -926,9 +948,7 @@ fn parse_primary<'a>(
                 parse_call_expr(id, input, pos, allow_stmt_expr)?
             }
             // Indexing
-            (expr, Token::LeftBracket) => {
+            (expr, Token::LeftBracket) => parse_index_chain(expr, input, pos, allow_stmt_expr)?,
-                parse_index_expr(Box::new(expr), input, pos, allow_stmt_expr)?
-            }
             // Unknown postfix operator
             (expr, token) => panic!("unknown postfix operator {:?} for {:?}", token, expr),
         }
@@ -1005,71 +1025,6 @@ fn parse_unary<'a>(
     }
 }
 
-/// Parse an assignment.
-fn parse_assignment(lhs: Expr, rhs: Expr, pos: Position) -> Result<Expr, Box<ParseError>> {
-    // Is the LHS in a valid format for an assignment target?
-    fn valid_assignment_chain(expr: &Expr, is_top: bool) -> Option<Box<ParseError>> {
-        match expr {
-            // var
-            Expr::Variable(_, _) => {
-                assert!(is_top, "property expected but gets variable");
-                None
-            }
-            // property
-            Expr::Property(_, _) => {
-                assert!(!is_top, "variable expected but gets property");
-                None
-            }
-
-            // idx_lhs[...]
-            Expr::Index(idx_lhs, _, pos) => match idx_lhs.as_ref() {
-                // var[...]
-                Expr::Variable(_, _) => {
-                    assert!(is_top, "property expected but gets variable");
-                    None
-                }
-                // property[...]
-                Expr::Property(_, _) => {
-                    assert!(!is_top, "variable expected but gets property");
-                    None
-                }
-                // ???[...][...]
-                Expr::Index(_, _, _) => Some(ParseErrorType::AssignmentToCopy.into_err(*pos)),
-                // idx_lhs[...]
-                _ => Some(ParseErrorType::AssignmentToInvalidLHS.into_err(*pos)),
-            },
-
-            // dot_lhs.dot_rhs
-            Expr::Dot(dot_lhs, dot_rhs, pos) => match dot_lhs.as_ref() {
-                // var.dot_rhs
-                Expr::Variable(_, _) if is_top => valid_assignment_chain(dot_rhs, false),
-                // property.dot_rhs
-                Expr::Property(_, _) if !is_top => valid_assignment_chain(dot_rhs, false),
-                // idx_lhs[...].dot_rhs
-                Expr::Index(idx_lhs, _, _) => match idx_lhs.as_ref() {
-                    // var[...].dot_rhs
-                    Expr::Variable(_, _) if is_top => valid_assignment_chain(dot_rhs, false),
-                    // property[...].dot_rhs
-                    Expr::Property(_, _) if !is_top => valid_assignment_chain(dot_rhs, false),
-                    // ???[...][...].dot_rhs
-                    Expr::Index(_, _, _) => Some(ParseErrorType::AssignmentToCopy.into_err(*pos)),
-                    // idx_lhs[...].dot_rhs
-                    _ => Some(ParseErrorType::AssignmentToCopy.into_err(idx_lhs.position())),
-                },
-
-                expr => panic!("unexpected dot expression {:#?}", expr),
-            },
-
-            _ => Some(ParseErrorType::AssignmentToInvalidLHS.into_err(expr.position())),
-        }
-    }
-
-    match valid_assignment_chain(&lhs, true) {
-        None => Ok(Expr::Assignment(Box::new(lhs), Box::new(rhs), pos)),
-        Some(err) => Err(err),
-    }
-}
-
 fn parse_assignment_stmt<'a>(
     input: &mut Peekable<TokenIterator<'a>>,
     lhs: Expr,
@@ -1077,7 +1032,7 @@ fn parse_assignment_stmt<'a>(
 ) -> Result<Expr, Box<ParseError>> {
     let pos = eat_token(input, Token::Equals);
     let rhs = parse_expr(input, allow_stmt_expr)?;
-    parse_assignment(lhs, rhs, pos)
+    Ok(Expr::Assignment(Box::new(lhs), Box::new(rhs), pos))
 }
 
 /// Parse an operator-assignment expression.
@@ -1108,15 +1063,52 @@ fn parse_op_assignment_stmt<'a>(
     let rhs = parse_expr(input, allow_stmt_expr)?;
 
     // lhs op= rhs -> lhs = op(lhs, rhs)
-    parse_assignment(
+    let rhs_expr = Expr::FunctionCall(op.into(), vec![lhs_copy, rhs], None, pos);
-        lhs,
+    Ok(Expr::Assignment(Box::new(lhs), Box::new(rhs_expr), pos))
-        Expr::FunctionCall(op.into(), vec![lhs_copy, rhs], None, pos),
-        pos,
-    )
 }
 
-/// Parse an 'in' expression.
+/// Make a dot expression.
-fn parse_in_expr(lhs: Expr, rhs: Expr, op_pos: Position) -> Result<Expr, Box<ParseError>> {
+fn make_dot_expr(lhs: Expr, rhs: Expr, op_pos: Position, is_index: bool) -> Expr {
+    match (lhs, rhs) {
+        // idx_lhs[idx_rhs].rhs
+        // Attach dot chain to the bottom level of indexing chain
+        (Expr::Index(idx_lhs, idx_rhs, idx_pos), rhs) => Expr::Index(
+            idx_lhs,
+            Box::new(make_dot_expr(*idx_rhs, rhs, op_pos, true)),
+            idx_pos,
+        ),
+        // lhs.id
+        (lhs, rhs @ Expr::Variable(_, _)) | (lhs, rhs @ Expr::Property(_, _)) => {
+            let lhs = if is_index { lhs.into_property() } else { lhs };
+            Expr::Dot(Box::new(lhs), Box::new(rhs.into_property()), op_pos)
+        }
+        // lhs.dot_lhs.dot_rhs
+        (lhs, Expr::Dot(dot_lhs, dot_rhs, dot_pos)) => Expr::Dot(
+            Box::new(lhs),
+            Box::new(Expr::Dot(
+                Box::new(dot_lhs.into_property()),
+                Box::new(dot_rhs.into_property()),
+                dot_pos,
+            )),
+            op_pos,
+        ),
+        // lhs.idx_lhs[idx_rhs]
+        (lhs, Expr::Index(idx_lhs, idx_rhs, idx_pos)) => Expr::Dot(
+            Box::new(lhs),
+            Box::new(Expr::Index(
+                Box::new(idx_lhs.into_property()),
+                Box::new(idx_rhs.into_property()),
+                idx_pos,
+            )),
+            op_pos,
+        ),
+        // lhs.rhs
+        (lhs, rhs) => Expr::Dot(Box::new(lhs), Box::new(rhs.into_property()), op_pos),
+    }
+}
+
+/// Make an 'in' expression.
+fn make_in_expr(lhs: Expr, rhs: Expr, op_pos: Position) -> Result<Expr, Box<ParseError>> {
     match (&lhs, &rhs) {
         (_, Expr::IntegerConstant(_, pos))
         | (_, Expr::FloatConstant(_, pos))
@@ -1321,34 +1313,10 @@ fn parse_binary_op<'a>(
             Token::Pipe => Expr::FunctionCall("|".into(), vec![current_lhs, rhs], None, pos),
             Token::XOr => Expr::FunctionCall("^".into(), vec![current_lhs, rhs], None, pos),
 
-            Token::In => parse_in_expr(current_lhs, rhs, pos)?,
+            Token::In => make_in_expr(current_lhs, rhs, pos)?,
 
             #[cfg(not(feature = "no_object"))]
-            Token::Period => {
+            Token::Period => make_dot_expr(current_lhs, rhs, pos, false),
-                fn check_property(expr: Expr) -> Result<Expr, Box<ParseError>> {
-                    match expr {
-                        // xxx.lhs.rhs
-                        Expr::Dot(lhs, rhs, pos) => Ok(Expr::Dot(
-                            Box::new(check_property(*lhs)?),
-                            Box::new(check_property(*rhs)?),
-                            pos,
-                        )),
-                        // xxx.lhs[idx]
-                        Expr::Index(lhs, idx, pos) => {
-                            Ok(Expr::Index(Box::new(check_property(*lhs)?), idx, pos))
-                        }
-                        // xxx.id
-                        Expr::Variable(id, pos) => Ok(Expr::Property(id, pos)),
-                        // xxx.prop
-                        expr @ Expr::Property(_, _) => Ok(expr),
-                        // xxx.fn()
-                        expr @ Expr::FunctionCall(_, _, _, _) => Ok(expr),
-                        expr => Err(PERR::PropertyExpected.into_err(expr.position())),
-                    }
-                }
-
-                Expr::Dot(Box::new(current_lhs), Box::new(check_property(rhs)?), pos)
-            }
 
             token => return Err(PERR::UnknownOperator(token.syntax().into()).into_err(pos)),
         };

src/scope.rs

@@ -25,15 +25,7 @@ pub struct Entry<'a> {
     /// Current value of the entry.
     pub value: Dynamic,
     /// A constant expression if the initial value matches one of the recognized types.
-    pub expr: Option<Expr>,
+    pub expr: Option<Box<Expr>>,
-}
-
-/// Information about a particular entry in the Scope.
-#[derive(Debug, Hash, Copy, Clone)]
-pub(crate) struct EntryRef<'a> {
-    pub name: &'a str,
-    pub index: usize,
-    pub typ: EntryType,
 }
 
 /// A type containing information about the current scope.
@@ -226,15 +218,17 @@ impl<'a> Scope<'a> {
         value: Dynamic,
         map_expr: bool,
     ) {
+        let expr = if map_expr {
+            map_dynamic_to_expr(value.clone(), Position::none()).map(Box::new)
+        } else {
+            None
+        };
+
         self.0.push(Entry {
             name: name.into(),
             typ: entry_type,
-            value: value.clone(),
+            value: value.into(),
-            expr: if map_expr {
+            expr,
-                map_dynamic_to_expr(value, Position::none())
-            } else {
-                None
-            },
         });
     }
 
@@ -289,35 +283,18 @@ impl<'a> Scope<'a> {
     }
 
     /// Find an entry in the Scope, starting from the last.
-    pub(crate) fn get(&self, name: &str) -> Option<(EntryRef, Dynamic)> {
+    pub(crate) fn get(&self, name: &str) -> Option<(usize, EntryType)> {
         self.0
             .iter()
             .enumerate()
             .rev() // Always search a Scope in reverse order
-            .find_map(
+            .find_map(|(index, Entry { name: key, typ, .. })| {
-                |(
+                if name == key {
-                    index,
+                    Some((index, *typ))
-                    Entry {
+                } else {
-                        name: key,
+                    None
-                        typ,
+                }
-                        value,
+            })
-                        ..
-                    },
-                )| {
-                    if name == key {
-                        Some((
-                            EntryRef {
-                                name: key,
-                                index,
-                                typ: *typ,
-                            },
-                            value.clone(),
-                        ))
-                    } else {
-                        None
-                    }
-                },
-            )
     }
 
     /// Get the value of an entry in the Scope, starting from the last.
@@ -363,36 +340,23 @@ impl<'a> Scope<'a> {
     /// ```
     pub fn set_value<T: Variant + Clone>(&mut self, name: &'a str, value: T) {
         match self.get(name) {
-            Some((
+            Some((_, EntryType::Constant)) => panic!("variable {} is constant", name),
-                EntryRef {
+            Some((index, EntryType::Normal)) => {
-                    typ: EntryType::Constant,
+                self.0.get_mut(index).unwrap().value = Dynamic::from(value)
-                    ..
+            }
-                },
-                _,
-            )) => panic!("variable {} is constant", name),
-            Some((
-                EntryRef {
-                    index,
-                    typ: EntryType::Normal,
-                    ..
-                },
-                _,
-            )) => self.0.get_mut(index).unwrap().value = Dynamic::from(value),
             None => self.push(name, value),
         }
     }
 
     /// Get a mutable reference to an entry in the Scope.
-    pub(crate) fn get_mut(&mut self, key: EntryRef) -> &mut Dynamic {
+    pub(crate) fn get_mut(&mut self, index: usize) -> &mut Dynamic {
-        let entry = self.0.get_mut(key.index).expect("invalid index in Scope");
+        let entry = self.0.get_mut(index).expect("invalid index in Scope");
-        assert_eq!(entry.typ, key.typ, "entry type not matched");
 
         // assert_ne!(
         //     entry.typ,
         //     EntryType::Constant,
         //     "get mut of constant entry"
         // );
-        assert_eq!(entry.name, key.name, "incorrect key at Scope entry");
 
         &mut entry.value
     }
@@ -409,16 +373,13 @@ impl Default for Scope<'_> {
     }
 }
 
-impl<'a, K> iter::Extend<(K, EntryType, Dynamic)> for Scope<'a>
+impl<'a, K: Into<Cow<'a, str>>> iter::Extend<(K, EntryType, Dynamic)> for Scope<'a> {
-where
-    K: Into<Cow<'a, str>>,
-{
     fn extend<T: IntoIterator<Item = (K, EntryType, Dynamic)>>(&mut self, iter: T) {
         self.0
             .extend(iter.into_iter().map(|(name, typ, value)| Entry {
                 name: name.into(),
                 typ,
-                value,
+                value: value.into(),
                 expr: None,
             }));
     }

tests/maps.rs

@@ -143,6 +143,7 @@ fn test_map_return() -> Result<(), Box<EvalAltResult>> {
 }
 
 #[test]
+#[cfg(not(feature = "no_index"))]
 fn test_map_for() -> Result<(), Box<EvalAltResult>> {
     let engine = Engine::new();