Use bit-flags for options.

src/api/compile.rs

@@ -201,11 +201,7 @@ impl Engine {
         scope: &Scope,
         scripts: impl AsRef<[S]>,
     ) -> ParseResult<AST> {
-        self.compile_with_scope_and_optimization_level(
+        self.compile_with_scope_and_optimization_level(scope, scripts, self.optimization_level)
-            scope,
-            scripts,
-            self.options.optimization_level,
-        )
     }
     /// Join a list of strings and compile into an [`AST`] using own scope at a specific optimization level.
     ///
@@ -296,6 +292,6 @@ impl Engine {
 
         let mut peekable = stream.peekable();
         let mut state = ParseState::new(self, scope, tokenizer_control);
-        self.parse_global_expr(&mut peekable, &mut state, self.options.optimization_level)
+        self.parse_global_expr(&mut peekable, &mut state, self.optimization_level)
     }
 }

src/api/eval.rs

@@ -67,7 +67,7 @@ impl Engine {
         let ast = self.compile_with_scope_and_optimization_level(
             scope,
             &[script],
-            self.options.optimization_level,
+            self.optimization_level,
         )?;
         self.eval_ast_with_scope(scope, &ast)
     }

src/api/optimize.rs

@@ -9,7 +9,7 @@ impl Engine {
     /// Not available under `no_optimize`.
     #[inline(always)]
     pub fn set_optimization_level(&mut self, optimization_level: OptimizationLevel) -> &mut Self {
-        self.options.optimization_level = optimization_level;
+        self.optimization_level = optimization_level;
         self
     }
 
@@ -20,7 +20,7 @@ impl Engine {
     #[inline(always)]
     #[must_use]
     pub const fn optimization_level(&self) -> OptimizationLevel {
-        self.options.optimization_level
+        self.optimization_level
     }
 
     /// Optimize the [`AST`] with constants defined in an external Scope.

src/api/options.rs

@@ -1,62 +1,47 @@
 //! Settings for [`Engine`]'s language options.
 
-use crate::{Engine, OptimizationLevel};
+use crate::Engine;
+use bitflags::bitflags;
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 
-/// A type containing all language options for the [`Engine`].
+bitflags! {
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+    /// Bit-flags containing all language options for the [`Engine`].
-pub struct LanguageOptions {
+    pub struct LangOptions: u8 {
-    /// Script optimization level.
+        /// Is `if`-expression allowed?
-    pub optimization_level: OptimizationLevel,
+        const IF_EXPR = 0b_00000001;
-    /// Is `if`-expression allowed?
+        /// Is `switch` expression allowed?
-    pub allow_if_expr: bool,
+        const SWITCH_EXPR = 0b_00000010;
-    /// Is `switch` expression allowed?
+        /// Is statement-expression allowed?
-    pub allow_switch_expr: bool,
+        const STMT_EXPR = 0b_00000100;
-    /// Is statement-expression allowed?
+        /// Is anonymous function allowed?
-    pub allow_stmt_expr: bool,
+        #[cfg(not(feature = "no_function"))]
-    /// Is anonymous function allowed?
+        const ANON_FN = 0b_00001000;
-    #[cfg(not(feature = "no_function"))]
+        /// Is looping allowed?
-    pub allow_anonymous_fn: bool,
+        const LOOPING = 0b_00010000;
-    /// Is looping allowed?
+        /// Is variables shadowing allowed?
-    pub allow_looping: bool,
+        const SHADOW = 0b_00100000;
-    /// Is variables shadowing allowed?
+        /// Strict variables mode?
-    pub allow_shadowing: bool,
+        const STRICT_VAR = 0b_01000000;
-    /// Strict variables mode?
+        /// Raise error if an object map property does not exist?
-    pub strict_var: bool,
+        /// Returns `()` if `false`.
-    /// Raise error if an object map property does not exist?
+        #[cfg(not(feature = "no_object"))]
-    /// Returns `()` if `false`.
+        const FAIL_ON_INVALID_MAP_PROPERTY = 0b_10000000;
-    #[cfg(not(feature = "no_object"))]
-    pub fail_on_invalid_map_property: bool,
-}
-
-impl LanguageOptions {
-    /// Create a new [`Options`] with default values.
-    #[inline(always)]
-    pub const fn new() -> Self {
-        Self {
-            #[cfg(not(feature = "no_optimize"))]
-            optimization_level: OptimizationLevel::Simple,
-            #[cfg(feature = "no_optimize")]
-            optimization_level: (),
-
-            allow_if_expr: true,
-            allow_switch_expr: true,
-            allow_stmt_expr: true,
-            #[cfg(not(feature = "no_function"))]
-            allow_anonymous_fn: true,
-            allow_looping: true,
-            strict_var: false,
-            allow_shadowing: true,
-            #[cfg(not(feature = "no_object"))]
-            fail_on_invalid_map_property: false,
-        }
     }
 }
 
-impl Default for LanguageOptions {
+impl LangOptions {
-    fn default() -> Self {
+    /// Create a new [`Options`] with default values.
-        Self::new()
+    #[inline(always)]
+    pub fn new() -> Self {
+        Self::IF_EXPR | Self::SWITCH_EXPR | Self::STMT_EXPR | Self::LOOPING | Self::SHADOW | {
+            #[cfg(not(feature = "no_function"))]
+            {
+                Self::ANON_FN
+            }
+            #[cfg(feature = "no_function")]
+            0
+        }
     }
 }
 
@@ -65,34 +50,34 @@ impl Engine {
     /// Default is `true`.
     #[inline(always)]
     pub const fn allow_if_expression(&self) -> bool {
-        self.options.allow_if_expr
+        self.options.contains(LangOptions::IF_EXPR)
     }
     /// Set whether `if`-expression is allowed.
     #[inline(always)]
     pub fn set_allow_if_expression(&mut self, enable: bool) {
-        self.options.allow_if_expr = enable;
+        self.options.set(LangOptions::IF_EXPR, enable)
     }
     /// Is `switch` expression allowed?
     /// Default is `true`.
     #[inline(always)]
     pub const fn allow_switch_expression(&self) -> bool {
-        self.options.allow_switch_expr
+        self.options.contains(LangOptions::SWITCH_EXPR)
     }
     /// Set whether `switch` expression is allowed.
     #[inline(always)]
     pub fn set_allow_switch_expression(&mut self, enable: bool) {
-        self.options.allow_switch_expr = enable;
+        self.options.set(LangOptions::SWITCH_EXPR, enable);
     }
     /// Is statement-expression allowed?
     /// Default is `true`.
     #[inline(always)]
     pub const fn allow_statement_expression(&self) -> bool {
-        self.options.allow_stmt_expr
+        self.options.contains(LangOptions::STMT_EXPR)
     }
     /// Set whether statement-expression is allowed.
     #[inline(always)]
     pub fn set_allow_statement_expression(&mut self, enable: bool) {
-        self.options.allow_stmt_expr = enable;
+        self.options.set(LangOptions::STMT_EXPR, enable);
     }
     /// Is anonymous function allowed?
     /// Default is `true`.
@@ -101,7 +86,7 @@ impl Engine {
     #[cfg(not(feature = "no_function"))]
     #[inline(always)]
     pub const fn allow_anonymous_fn(&self) -> bool {
-        self.options.allow_anonymous_fn
+        self.options.contains(LangOptions::ANON_FN)
     }
     /// Set whether anonymous function is allowed.
     ///
@@ -109,40 +94,40 @@ impl Engine {
     #[cfg(not(feature = "no_function"))]
     #[inline(always)]
     pub fn set_allow_anonymous_fn(&mut self, enable: bool) {
-        self.options.allow_anonymous_fn = enable;
+        self.options.set(LangOptions::ANON_FN, enable);
     }
     /// Is looping allowed?
     /// Default is `true`.
     #[inline(always)]
     pub const fn allow_looping(&self) -> bool {
-        self.options.allow_looping
+        self.options.contains(LangOptions::LOOPING)
     }
     /// Set whether looping is allowed.
     #[inline(always)]
     pub fn set_allow_looping(&mut self, enable: bool) {
-        self.options.allow_looping = enable;
+        self.options.set(LangOptions::LOOPING, enable);
     }
     /// Is variables shadowing allowed?
     /// Default is `true`.
     #[inline(always)]
     pub const fn allow_shadowing(&self) -> bool {
-        self.options.allow_shadowing
+        self.options.contains(LangOptions::SHADOW)
     }
     /// Set whether variables shadowing is allowed.
     #[inline(always)]
     pub fn set_allow_shadowing(&mut self, enable: bool) {
-        self.options.allow_shadowing = enable;
+        self.options.set(LangOptions::SHADOW, enable);
     }
     /// Is strict variables mode enabled?
     /// Default is `false`.
     #[inline(always)]
     pub const fn strict_variables(&self) -> bool {
-        self.options.strict_var
+        self.options.contains(LangOptions::STRICT_VAR)
     }
     /// Set whether strict variables mode is enabled.
     #[inline(always)]
     pub fn set_strict_variables(&mut self, enable: bool) {
-        self.options.strict_var = enable;
+        self.options.set(LangOptions::STRICT_VAR, enable);
     }
     /// Raise error if an object map property does not exist?
     /// Default is `false`.
@@ -151,7 +136,8 @@ impl Engine {
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
     pub const fn fail_on_invalid_map_property(&self) -> bool {
-        self.options.fail_on_invalid_map_property
+        self.options
+            .contains(LangOptions::FAIL_ON_INVALID_MAP_PROPERTY)
     }
     /// Set whether to raise error if an object map property does not exist.
     ///
@@ -159,6 +145,7 @@ impl Engine {
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
     pub fn set_fail_on_invalid_map_property(&mut self, enable: bool) {
-        self.options.fail_on_invalid_map_property = enable;
+        self.options
+            .set(LangOptions::FAIL_ON_INVALID_MAP_PROPERTY, enable);
     }
 }

src/api/run.rs

@@ -26,11 +26,7 @@ impl Engine {
             self.lex_raw(&scripts, self.token_mapper.as_ref().map(Box::as_ref));
         let mut state = ParseState::new(self, scope, tokenizer_control);
 
-        let ast = self.parse(
+        let ast = self.parse(&mut stream.peekable(), &mut state, self.optimization_level)?;
-            &mut stream.peekable(),
-            &mut state,
-            self.options.optimization_level,
-        )?;
 
         self.run_ast_with_scope(scope, &ast)
     }

src/ast/flags.rs

@@ -15,7 +15,7 @@ pub enum FnAccess {
 }
 
 bitflags! {
-    /// _(internals)_ A type that holds a configuration option with bit-flags.
+    /// _(internals)_ Bit-flags containing [`AST`][crate::AST] node configuration options.
     /// Exported under the `internals` feature only.
     pub struct ASTFlags: u8 {
         /// No options for the [`AST`][crate::AST] node.

src/engine.rs

@@ -1,7 +1,7 @@
 //! Main module defining the script evaluation [`Engine`].
 
 use crate::api::custom_syntax::CustomSyntax;
-use crate::api::options::LanguageOptions;
+use crate::api::options::LangOptions;
 use crate::func::native::{
     OnDebugCallback, OnDefVarCallback, OnParseTokenCallback, OnPrintCallback, OnVarCallback,
 };
@@ -9,7 +9,8 @@ use crate::packages::{Package, StandardPackage};
 use crate::tokenizer::Token;
 use crate::types::dynamic::Union;
 use crate::{
-    Dynamic, Identifier, ImmutableString, Module, Position, RhaiResult, Shared, StaticVec,
+    Dynamic, Identifier, ImmutableString, Module, OptimizationLevel, Position, RhaiResult, Shared,
+    StaticVec,
 };
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
@@ -129,7 +130,10 @@ pub struct Engine {
     pub(crate) progress: Option<Box<crate::func::native::OnProgressCallback>>,
 
     /// Language options.
-    pub(crate) options: LanguageOptions,
+    pub(crate) options: LangOptions,
+
+    /// Script optimization level.
+    pub optimization_level: OptimizationLevel,
 
     /// Max limits.
     #[cfg(not(feature = "unchecked"))]
@@ -274,7 +278,12 @@ impl Engine {
             #[cfg(not(feature = "unchecked"))]
             progress: None,
 
-            options: LanguageOptions::new(),
+            options: LangOptions::new(),
+
+            #[cfg(not(feature = "no_optimize"))]
+            optimization_level: OptimizationLevel::Simple,
+            #[cfg(feature = "no_optimize")]
+            optimization_level: (),
 
             #[cfg(not(feature = "unchecked"))]
             limits: crate::api::limits::Limits::new(),

src/parser.rs

@@ -2,7 +2,7 @@
 
 use crate::api::custom_syntax::{markers::*, CustomSyntax};
 use crate::api::events::VarDefInfo;
-use crate::api::options::LanguageOptions;
+use crate::api::options::LangOptions;
 use crate::ast::{
     ASTFlags, BinaryExpr, ConditionalStmtBlock, CustomExpr, Expr, FnCallExpr, FnCallHashes, Ident,
     OpAssignment, ScriptFnDef, Stmt, StmtBlock, StmtBlockContainer, SwitchCases, TryCatchBlock,
@@ -215,7 +215,7 @@ struct ParseSettings {
     /// Is the current position inside a loop?
     is_breakable: bool,
     /// Language options in effect (overrides Engine options).
-    options: LanguageOptions,
+    options: LangOptions,
     /// Current expression nesting level.
     level: usize,
     /// Current position.
@@ -501,7 +501,10 @@ impl Engine {
                     #[cfg(feature = "no_function")]
                     let relax = false;
 
-                    if !relax && settings.options.strict_var && index.is_none() {
+                    if !relax
+                        && settings.options.contains(LangOptions::STRICT_VAR)
+                        && index.is_none()
+                    {
                         return Err(PERR::ModuleUndefined(namespace.root().to_string())
                             .into_err(namespace.position()));
                     }
@@ -561,7 +564,10 @@ impl Engine {
                         #[cfg(feature = "no_function")]
                         let relax = false;
 
-                        if !relax && settings.options.strict_var && index.is_none() {
+                        if !relax
+                            && settings.options.contains(LangOptions::STRICT_VAR)
+                            && index.is_none()
+                        {
                             return Err(PERR::ModuleUndefined(namespace.root().to_string())
                                 .into_err(namespace.position()));
                         }
@@ -1234,7 +1240,7 @@ impl Engine {
             }
 
             // { - block statement as expression
-            Token::LeftBrace if settings.options.allow_stmt_expr => {
+            Token::LeftBrace if settings.options.contains(LangOptions::STMT_EXPR) => {
                 match self.parse_block(input, state, lib, settings.level_up())? {
                     block @ Stmt::Block(..) => Expr::Stmt(Box::new(block.into())),
                     stmt => unreachable!("Stmt::Block expected but gets {:?}", stmt),
@@ -1245,19 +1251,21 @@ impl Engine {
             Token::LeftParen => self.parse_paren_expr(input, state, lib, settings.level_up())?,
 
             // If statement is allowed to act as expressions
-            Token::If if settings.options.allow_if_expr => Expr::Stmt(Box::new(
+            Token::If if settings.options.contains(LangOptions::IF_EXPR) => Expr::Stmt(Box::new(
                 self.parse_if(input, state, lib, settings.level_up())?
                     .into(),
             )),
             // Switch statement is allowed to act as expressions
-            Token::Switch if settings.options.allow_switch_expr => Expr::Stmt(Box::new(
+            Token::Switch if settings.options.contains(LangOptions::SWITCH_EXPR) => {
-                self.parse_switch(input, state, lib, settings.level_up())?
+                Expr::Stmt(Box::new(
-                    .into(),
+                    self.parse_switch(input, state, lib, settings.level_up())?
-            )),
+                        .into(),
+                ))
+            }
 
             // | ...
             #[cfg(not(feature = "no_function"))]
-            Token::Pipe | Token::Or if settings.options.allow_anonymous_fn => {
+            Token::Pipe | Token::Or if settings.options.contains(LangOptions::ANON_FN) => {
                 let mut new_state =
                     ParseState::new(self, state.scope, state.tokenizer_control.clone());
 
@@ -1266,6 +1274,17 @@ impl Engine {
                     new_state.max_expr_depth = self.max_function_expr_depth();
                 }
 
+                let mut options = self.options;
+                options.set(
+                    LangOptions::STRICT_VAR,
+                    if cfg!(feature = "no_closure") {
+                        settings.options.contains(LangOptions::STRICT_VAR)
+                    } else {
+                        // A capturing closure can access variables not defined locally
+                        false
+                    },
+                );
+
                 let new_settings = ParseSettings {
                     is_global: false,
                     is_function_scope: true,
@@ -1273,15 +1292,7 @@ impl Engine {
                     is_closure_scope: true,
                     is_breakable: false,
                     level: 0,
-                    options: LanguageOptions {
+                    options,
-                        strict_var: if cfg!(feature = "no_closure") {
-                            settings.options.strict_var
-                        } else {
-                            // A capturing closure can access variables not defined locally
-                            false
-                        },
-                        ..self.options
-                    },
                     ..settings
                 };
 
@@ -1292,7 +1303,7 @@ impl Engine {
                     |crate::ast::Ident { name, pos }| {
                         let index = state.access_var(name, *pos);
 
-                        if settings.options.strict_var
+                        if settings.options.contains(LangOptions::STRICT_VAR)
                             && !settings.is_closure_scope
                             && index.is_none()
                             && !state.scope.contains(name)
@@ -1439,7 +1450,7 @@ impl Engine {
                     _ => {
                         let index = state.access_var(&s, settings.pos);
 
-                        if settings.options.strict_var
+                        if settings.options.contains(LangOptions::STRICT_VAR)
                             && index.is_none()
                             && !state.scope.contains(&s)
                         {
@@ -1674,7 +1685,10 @@ impl Engine {
                     #[cfg(feature = "no_function")]
                     let relax = false;
 
-                    if !relax && settings.options.strict_var && index.is_none() {
+                    if !relax
+                        && settings.options.contains(LangOptions::STRICT_VAR)
+                        && index.is_none()
+                    {
                         return Err(PERR::ModuleUndefined(namespace.root().to_string())
                             .into_err(namespace.position()));
                     }
@@ -3072,6 +3086,12 @@ impl Engine {
                             new_state.max_expr_depth = self.max_function_expr_depth();
                         }
 
+                        let mut options = self.options;
+                        options.set(
+                            LangOptions::STRICT_VAR,
+                            settings.options.contains(LangOptions::STRICT_VAR),
+                        );
+
                         let new_settings = ParseSettings {
                             is_global: false,
                             is_function_scope: true,
@@ -3079,10 +3099,7 @@ impl Engine {
                             is_closure_scope: false,
                             is_breakable: false,
                             level: 0,
-                            options: LanguageOptions {
+                            options,
-                                strict_var: settings.options.strict_var,
-                                ..self.options
-                            },
                             pos,
                             ..settings
                         };
@@ -3541,6 +3558,11 @@ impl Engine {
     ) -> ParseResult<AST> {
         let mut functions = BTreeMap::new();
 
+        let mut options = self.options;
+        options.remove(LangOptions::IF_EXPR | LangOptions::SWITCH_EXPR | LangOptions::STMT_EXPR);
+        #[cfg(not(feature = "no_function"))]
+        options.remove(LangOptions::ANON_FN);
+
         let settings = ParseSettings {
             is_global: true,
             #[cfg(not(feature = "no_function"))]
@@ -3550,14 +3572,7 @@ impl Engine {
             is_closure_scope: false,
             is_breakable: false,
             level: 0,
-            options: LanguageOptions {
+            options,
-                allow_if_expr: false,
-                allow_switch_expr: false,
-                allow_stmt_expr: false,
-                #[cfg(not(feature = "no_function"))]
-                allow_anonymous_fn: false,
-                ..self.options
-            },
             pos: Position::NONE,
         };
         let expr = self.parse_expr(input, state, &mut functions, settings)?;