Minor refactor.

src/custom_syntax.rs

@@ -335,7 +335,6 @@ impl Engine {
     /// * `Ok(None)`: parsing complete and there are no more symbols to match.
     /// * `Ok(Some(symbol))`: the next symbol to match, which can also be `$expr$`, `$ident$` or `$block$`.
     /// * `Err(ParseError)`: error that is reflected back to the [`Engine`], normally `ParseError(ParseErrorType::BadInput(LexError::ImproperSymbol(message)), Position::NONE)` to indicate a syntax error, but it can be any [`ParseError`].
-    ///
     pub fn register_custom_syntax_raw(
         &mut self,
         key: impl Into<Identifier>,

src/func/call.rs

@@ -313,7 +313,7 @@ impl Engine {
         name: impl AsRef<str>,
         hash: u64,
         args: &mut FnCallArgs,
-        is_method_call: bool,
+        is_ref_mut: bool,
         is_op_assign: bool,
         pos: Position,
     ) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
@@ -331,7 +331,8 @@ impl Engine {
 
             // Calling pure function but the first argument is a reference?
             let mut backup: Option<ArgBackup> = None;
-            if is_method_call && func.is_pure() && !args.is_empty() {
+            if is_ref_mut && func.is_pure() && !args.is_empty() {
+                // Clone the first argument
                 backup = Some(ArgBackup::new());
                 backup
                     .as_mut()
@@ -397,6 +398,8 @@ impl Engine {
             });
         }
 
+        // Error handling
+
         match name {
             // index getter function not found?
             #[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]

src/optimizer.rs

@@ -22,9 +22,6 @@ use std::{
     ops::DerefMut,
 };
 
-#[cfg(not(feature = "no_closure"))]
-use crate::engine::KEYWORD_IS_SHARED;
-
 /// Level of optimization performed.
 #[derive(Debug, Eq, PartialEq, Hash, Clone, Copy)]
 pub enum OptimizationLevel {
@@ -986,7 +983,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                     return;
                 }
                 #[cfg(not(feature = "no_closure"))]
-                KEYWORD_IS_SHARED if arg_values.len() == 1 => {
+                crate::engine::KEYWORD_IS_SHARED if arg_values.len() == 1 => {
                     state.set_dirty();
                     *expr = Expr::from_dynamic(Dynamic::FALSE, *pos);
                     return;
@@ -1046,7 +1043,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                 let result = match x.name.as_str() {
                     KEYWORD_TYPE_OF if arg_values.len() == 1 => Some(state.engine.map_type_name(arg_values[0].type_name()).into()),
                     #[cfg(not(feature = "no_closure"))]
-                    KEYWORD_IS_SHARED if arg_values.len() == 1 => Some(Dynamic::FALSE),
+                    crate::engine::KEYWORD_IS_SHARED if arg_values.len() == 1 => Some(Dynamic::FALSE),
                     _ => state.call_fn_with_constant_arguments(&x.name, arg_values)
                 };
 

tests/fn_ptr.rs

@@ -143,7 +143,7 @@ fn test_fn_ptr_make_closure() -> Result<(), Box<EvalAltResult>> {
 
         let fn_ptr = engine.eval_ast::<FnPtr>(&ast)?;
 
-        move |x: INT| -> Result<String, Box<EvalAltResult>> { fn_ptr.call(&engine, &ast, (x,)) }
+        move |x: INT| -> Result<String, _> { fn_ptr.call(&engine, &ast, (x,)) }
     };
 
     // 'f' captures: the Engine, the AST, and the closure