Add feature to disable symbols.

src/settings.rs

@@ -0,0 +1,203 @@
+use crate::engine::Engine;
+use crate::module::ModuleResolver;
+use crate::optimize::OptimizationLevel;
+use crate::packages::PackageLibrary;
+
+impl Engine {
+    /// Load a new package into the `Engine`.
+    ///
+    /// When searching for functions, packages loaded later are preferred.
+    /// In other words, loaded packages are searched in reverse order.
+    pub fn load_package(&mut self, package: PackageLibrary) {
+        // Push the package to the top - packages are searched in reverse order
+        self.packages.push(package);
+    }
+
+    /// Load a new package into the `Engine`.
+    ///
+    /// When searching for functions, packages loaded later are preferred.
+    /// In other words, loaded packages are searched in reverse order.
+    pub fn load_packages(&mut self, package: PackageLibrary) {
+        // Push the package to the top - packages are searched in reverse order
+        self.packages.push(package);
+    }
+
+    /// Control whether and how the `Engine` will optimize an AST after compilation.
+    ///
+    /// Not available under the `no_optimize` feature.
+    #[cfg(not(feature = "no_optimize"))]
+    pub fn set_optimization_level(&mut self, optimization_level: OptimizationLevel) {
+        self.optimization_level = optimization_level
+    }
+
+    /// The current optimization level.
+    /// It controls whether and how the `Engine` will optimize an AST after compilation.
+    ///
+    /// Not available under the `no_optimize` feature.
+    #[cfg(not(feature = "no_optimize"))]
+    pub fn optimization_level(&self) -> OptimizationLevel {
+        self.optimization_level
+    }
+
+    /// Set the maximum levels of function calls allowed for a script in order to avoid
+    /// infinite recursion and stack overflows.
+    #[cfg(not(feature = "unchecked"))]
+    pub fn set_max_call_levels(&mut self, levels: usize) {
+        self.max_call_stack_depth = levels
+    }
+
+    /// The maximum levels of function calls allowed for a script.
+    #[cfg(not(feature = "unchecked"))]
+    pub fn max_call_levels(&self) -> usize {
+        self.max_call_stack_depth
+    }
+
+    /// Set the maximum number of operations allowed for a script to run to avoid
+    /// consuming too much resources (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn set_max_operations(&mut self, operations: u64) {
+        self.max_operations = if operations == u64::MAX {
+            0
+        } else {
+            operations
+        };
+    }
+
+    /// The maximum number of operations allowed for a script to run (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn max_operations(&self) -> u64 {
+        self.max_operations
+    }
+
+    /// Set the maximum number of imported modules allowed for a script.
+    #[cfg(not(feature = "unchecked"))]
+    pub fn set_max_modules(&mut self, modules: usize) {
+        self.max_modules = modules;
+    }
+
+    /// The maximum number of imported modules allowed for a script.
+    #[cfg(not(feature = "unchecked"))]
+    pub fn max_modules(&self) -> usize {
+        self.max_modules
+    }
+
+    /// Set the depth limits for expressions (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn set_max_expr_depths(&mut self, max_expr_depth: usize, max_function_expr_depth: usize) {
+        self.max_expr_depth = if max_expr_depth == usize::MAX {
+            0
+        } else {
+            max_expr_depth
+        };
+        self.max_function_expr_depth = if max_function_expr_depth == usize::MAX {
+            0
+        } else {
+            max_function_expr_depth
+        };
+    }
+
+    /// The depth limit for expressions (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn max_expr_depth(&self) -> usize {
+        self.max_expr_depth
+    }
+
+    /// The depth limit for expressions in functions (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn max_function_expr_depth(&self) -> usize {
+        self.max_function_expr_depth
+    }
+
+    /// Set the maximum length of strings (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn set_max_string_size(&mut self, max_size: usize) {
+        self.max_string_size = if max_size == usize::MAX { 0 } else { max_size };
+    }
+
+    /// The maximum length of strings (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    pub fn max_string_size(&self) -> usize {
+        self.max_string_size
+    }
+
+    /// Set the maximum length of arrays (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    #[cfg(not(feature = "no_index"))]
+    pub fn set_max_array_size(&mut self, max_size: usize) {
+        self.max_array_size = if max_size == usize::MAX { 0 } else { max_size };
+    }
+
+    /// The maximum length of arrays (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    #[cfg(not(feature = "no_index"))]
+    pub fn max_array_size(&self) -> usize {
+        self.max_array_size
+    }
+
+    /// Set the maximum length of object maps (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    #[cfg(not(feature = "no_object"))]
+    pub fn set_max_map_size(&mut self, max_size: usize) {
+        self.max_map_size = if max_size == usize::MAX { 0 } else { max_size };
+    }
+
+    /// The maximum length of object maps (0 for unlimited).
+    #[cfg(not(feature = "unchecked"))]
+    #[cfg(not(feature = "no_object"))]
+    pub fn max_map_size(&self) -> usize {
+        self.max_map_size
+    }
+
+    /// Set the module resolution service used by the `Engine`.
+    ///
+    /// Not available under the `no_module` feature.
+    #[cfg(not(feature = "no_module"))]
+    pub fn set_module_resolver(&mut self, resolver: Option<impl ModuleResolver + 'static>) {
+        self.module_resolver = resolver.map(|f| Box::new(f) as Box<dyn ModuleResolver>);
+    }
+
+    /// Disable a particular keyword or operator in the language.
+    ///
+    /// # Examples
+    ///
+    /// The following will raise an error during parsing because the `if` keyword is disabled
+    /// and is recognized as a variable name!
+    ///
+    /// ```rust,should_panic
+    /// # fn main() -> Result<(), rhai::ParseError> {
+    /// use rhai::Engine;
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// engine.disable_symbol("if");    // disable the 'if' keyword
+    ///
+    /// engine.compile("let x = if true { 42 } else { 0 };")?;
+    /// //                      ^ 'if' is parsed as a variable name
+    /// //                         ^ missing ';' after statement end
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// The following will raise an error during parsing because the `+=` operator is disabled.
+    ///
+    /// ```rust,should_panic
+    /// # fn main() -> Result<(), rhai::ParseError> {
+    /// use rhai::Engine;
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// engine.disable_symbol("+=");    // disable the '+=' operator
+    ///
+    /// engine.compile("let x = 42; x += 1;")?;
+    /// //                            ^ unknown operator
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn disable_symbol(&mut self, symbol: &str) {
+        if self.disable_tokens.is_none() {
+            self.disable_tokens = Some(Default::default());
+        }
+
+        self.disable_tokens.as_mut().unwrap().insert(symbol.into());
+    }
+}