Fix bug in custom syntax starting with disabled stardard keyword.

CHANGELOG.md

@@ -4,6 +4,11 @@ Rhai Release Notes
 Version 1.1.0
 =============
 
+Bug fixes
+---------
+
+* Custom syntax starting with a disabled standard keyword now works properly.
+
 Enhancements
 ------------
 
@@ -16,6 +21,7 @@ Enhancements
 * `parse_float()`, `PI()` and `E()` now defer to `Decimal` under `no_float` if `decimal` is turned on.
 * Added `log10()` for `Decimal`.
 * `ln` for `Decimal` is now checked and won't panic.
+* `Scope::set_value` now takes anything that implements `Into<Cow<str>>`.
 
 
 Version 1.0.2

src/custom_syntax.rs

@@ -230,11 +230,10 @@ impl Engine {
                     }
                     s.into()
                 }
-                // Standard keyword in first position
-                s if segments.is_empty()
-                    && token
-                        .as_ref()
-                        .map_or(false, |v| v.is_standard_keyword() || v.is_reserved()) =>
+                // Standard keyword in first position but not disabled
+                _ if segments.is_empty()
+                    && token.as_ref().map_or(false, |v| v.is_standard_keyword())
+                    && !self.disabled_symbols.contains(s) =>
                 {
                     return Err(LexError::ImproperSymbol(
                         s.to_string(),
@@ -247,14 +246,14 @@ impl Engine {
                     .into_err(Position::NONE));
                 }
                 // Identifier in first position
-                s if segments.is_empty() && is_valid_identifier(s.chars()) => {
+                _ if segments.is_empty() && is_valid_identifier(s.chars()) => {
                     // Make it a custom keyword/symbol if it is disabled or reserved
-                    if (self.disabled_symbols.contains(s)
-                        || matches!(token, Some(Token::Reserved(_))))
-                        && !self.custom_keywords.contains_key(s)
+                    if self.disabled_symbols.contains(s) || token.map_or(false, |v| v.is_reserved())
                     {
+                        if !self.custom_keywords.contains_key(s) {
                             self.custom_keywords.insert(s.into(), None);
                         }
+                    }
                     s.into()
                 }
                 // Anything else is an error

tests/custom_syntax.rs

@@ -1,5 +1,5 @@
 use rhai::{
-    Dynamic, Engine, EvalAltResult, ImmutableString, LexError, ParseErrorType, Position, INT,
+    Dynamic, Engine, EvalAltResult, ImmutableString, LexError, ParseErrorType, Position, Scope, INT,
 };
 
 #[test]
@@ -146,6 +146,42 @@ fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
     assert_eq!(engine.eval::<INT>("test2 } 42")?, 42);
     assert_eq!(engine.eval::<INT>("test3; 42")?, 42);
 
+    // Register the custom syntax: var x = ???
+    engine.register_custom_syntax(
+        &["var", "$ident$", "=", "$expr$"],
+        true,
+        |context, inputs| {
+            let var_name = inputs[0].get_variable_name().unwrap().to_string();
+            let expr = &inputs[1];
+
+            // Evaluate the expression
+            let value = context.eval_expression_tree(expr)?;
+
+            // Push new variable into the scope if it doesn't already exist.
+            // Otherwise set its value.
+            // WARNING - This panics if 'var_name' already exists and is constant!
+            //         - In a real implementation, check this before doing anything!
+            context.scope_mut().set_value(var_name, value);
+
+            Ok(Dynamic::UNIT)
+        },
+    )?;
+
+    let mut scope = Scope::new();
+
+    assert_eq!(
+        engine.eval_with_scope::<INT>(&mut scope, "var foo = 42; foo")?,
+        42
+    );
+    assert_eq!(scope.get_value::<INT>("foo"), Some(42));
+    assert_eq!(scope.len(), 1);
+    assert_eq!(
+        engine.eval_with_scope::<INT>(&mut scope, "var foo = 123; foo")?,
+        123
+    );
+    assert_eq!(scope.get_value::<INT>("foo"), Some(123));
+    assert_eq!(scope.len(), 1);
+
     Ok(())
 }