Remove no_smartstring feature.

CHANGELOG.md

@@ -14,6 +14,11 @@ Enhancements
 
 * Added `into_array` and `into_typed_array` for `Dynamic`.
 
+Deprecated API's
+----------------
+
+* The internal `no_smartstring` feature is removed since `SmartString` now supports `no-std`.
+
 
 Version 1.2.1
 =============

Cargo.toml

@@ -48,9 +48,6 @@ no_std = ["no-std-compat", "num-traits/libm", "core-error", "libm", "ahash/compi
 wasm-bindgen = ["instant/wasm-bindgen"]
 stdweb = ["instant/stdweb"]
 
-# internal feature flags - volatile
-no_smartstring = []             # do not use SmartString
-
 [profile.release]
 lto = "fat"
 codegen-units = 1

src/ast.rs

@@ -228,7 +228,7 @@ impl AST {
     pub fn empty() -> Self {
         Self {
             source: None,
-            body: StmtBlock::empty(Position::NONE),
+            body: StmtBlock::NONE,
             functions: Module::new().into(),
             #[cfg(not(feature = "no_module"))]
             resolver: None,
@@ -401,7 +401,7 @@ impl AST {
         functions.merge_filtered(&self.functions, &filter);
         Self {
             source: self.source.clone(),
-            body: StmtBlock::empty(Position::NONE),
+            body: StmtBlock::NONE,
             functions: functions.into(),
             #[cfg(not(feature = "no_module"))]
             resolver: self.resolver.clone(),
@@ -597,7 +597,7 @@ impl AST {
             }
             (false, true) => body.clone(),
             (true, false) => other.body.clone(),
-            (true, true) => StmtBlock::empty(Position::NONE),
+            (true, true) => StmtBlock::NONE,
         };
 
         let source = other.source.clone().or_else(|| self.source.clone());
@@ -744,7 +744,7 @@ impl AST {
     /// Clear all statements in the [`AST`], leaving only function definitions.
     #[inline(always)]
     pub fn clear_statements(&mut self) -> &mut Self {
-        self.body = StmtBlock::empty(Position::NONE);
+        self.body = StmtBlock::NONE;
         self
     }
     /// Extract all top-level literal constant and/or variable definitions.
@@ -987,6 +987,9 @@ impl ASTNode<'_> {
 pub struct StmtBlock(StaticVec<Stmt>, Position);
 
 impl StmtBlock {
+    /// A [`StmtBlock`] that does not exist.
+    pub const NONE: Self = Self::empty(Position::NONE);
+
     /// Create a new [`StmtBlock`].
     #[must_use]
     pub fn new(statements: impl IntoIterator<Item = Stmt>, pos: Position) -> Self {

src/engine.rs

@@ -797,6 +797,12 @@ impl EvalState {
     pub const fn is_global(&self) -> bool {
         self.scope_level == 0
     }
+    /// Get the number of function resolution cache(s) in the stack.
+    #[inline(always)]
+    #[must_use]
+    pub fn fn_resolution_caches_len(&self) -> usize {
+        self.fn_resolution_caches.len()
+    }
     /// Get a mutable reference to the current function resolution cache.
     #[inline]
     #[must_use]
@@ -813,14 +819,10 @@ impl EvalState {
     pub fn push_fn_resolution_cache(&mut self) {
         self.fn_resolution_caches.push(BTreeMap::new());
     }
-    /// Remove the current function resolution cache from the stack and make the last one current.
+    /// Rewind the function resolution caches stack to a particular size.
-    ///
-    /// # Panics
-    ///
-    /// Panics if there is no more function resolution cache in the stack.
     #[inline(always)]
-    pub fn pop_fn_resolution_cache(&mut self) {
+    pub fn rewind_fn_resolution_caches(&mut self, len: usize) {
-        self.fn_resolution_caches.pop().expect("not empty");
+        self.fn_resolution_caches.truncate(len);
     }
 }
 
@@ -2444,7 +2446,7 @@ impl Engine {
         lib: &[&Module],
         this_ptr: &mut Option<&mut Dynamic>,
         statements: &[Stmt],
-        restore_prev_state: bool,
+        restore_orig_state: bool,
         rewind_scope: bool,
         level: usize,
     ) -> RhaiResult {
@@ -2452,10 +2454,10 @@ impl Engine {
             return Ok(Dynamic::UNIT);
         }
 
-        let mut _extra_fn_resolution_cache = false;
+        let orig_always_search_scope = state.always_search_scope;
-        let prev_always_search_scope = state.always_search_scope;
+        let orig_scope_len = scope.len();
-        let prev_scope_len = scope.len();
+        let orig_mods_len = mods.len();
-        let prev_mods_len = mods.len();
+        let orig_fn_resolution_caches_len = state.fn_resolution_caches_len();
 
         if rewind_scope {
             state.scope_level += 1;
@@ -2475,15 +2477,14 @@ impl Engine {
                     .skip(_mods_len)
                     .any(|(_, m)| m.contains_indexed_global_functions())
                 {
-                    if _extra_fn_resolution_cache {
+                    if state.fn_resolution_caches_len() > orig_fn_resolution_caches_len {
                         // When new module is imported with global functions and there is already
                         // a new cache, clear it - notice that this is expensive as all function
                         // resolutions must start again
                         state.fn_resolution_cache_mut().clear();
-                    } else if restore_prev_state {
+                    } else if restore_orig_state {
                         // When new module is imported with global functions, push a new cache
                         state.push_fn_resolution_cache();
-                        _extra_fn_resolution_cache = true;
                     } else {
                         // When the block is to be evaluated in-place, just clear the current cache
                         state.fn_resolution_cache_mut().clear();
@@ -2494,21 +2495,19 @@ impl Engine {
             Ok(r)
         });
 
-        if _extra_fn_resolution_cache {
         // If imports list is modified, pop the functions lookup cache
-            state.pop_fn_resolution_cache();
+        state.rewind_fn_resolution_caches(orig_fn_resolution_caches_len);
-        }
 
         if rewind_scope {
-            scope.rewind(prev_scope_len);
+            scope.rewind(orig_scope_len);
             state.scope_level -= 1;
         }
-        if restore_prev_state {
+        if restore_orig_state {
-            mods.truncate(prev_mods_len);
+            mods.truncate(orig_mods_len);
 
             // The impact of new local variables goes away at the end of a block
             // because any new variables introduced will go out of scope
-            state.always_search_scope = prev_always_search_scope;
+            state.always_search_scope = orig_always_search_scope;
         }
 
         result

src/func/call.rs

@@ -530,8 +530,8 @@ impl Engine {
             return Err(EvalAltResult::ErrorStackOverflow(pos).into());
         }
 
-        let prev_scope_len = scope.len();
+        let orig_scope_len = scope.len();
-        let prev_mods_len = mods.len();
+        let orig_mods_len = mods.len();
 
         // Put arguments into scope as variables
         // Actually consume the arguments instead of cloning them
@@ -549,14 +549,19 @@ impl Engine {
 
         // Merge in encapsulated environment, if any
         let mut lib_merged = StaticVec::with_capacity(lib.len() + 1);
+        let orig_fn_resolution_caches_len = state.fn_resolution_caches_len();
 
-        let (unified, is_unified) = if let Some(ref env_lib) = fn_def.lib {
+        let lib = if let Some(ref env_lib) = fn_def.lib {
+            if env_lib.is_empty() {
+                lib
+            } else {
                 state.push_fn_resolution_cache();
                 lib_merged.push(env_lib.as_ref());
                 lib_merged.extend(lib.iter().cloned());
-            (lib_merged.as_ref(), true)
+                lib_merged.as_ref()
+            }
         } else {
-            (lib, false)
+            lib
         };
 
         #[cfg(not(feature = "no_module"))]
@@ -574,7 +579,7 @@ impl Engine {
                 scope,
                 mods,
                 state,
-                unified,
+                lib,
                 this_ptr,
                 body,
                 true,
@@ -605,17 +610,14 @@ impl Engine {
 
         // Remove all local variables
         if rewind_scope {
-            scope.rewind(prev_scope_len);
+            scope.rewind(orig_scope_len);
         } else if !args.is_empty() {
             // Remove arguments only, leaving new variables in the scope
-            scope.remove_range(prev_scope_len, args.len())
+            scope.remove_range(orig_scope_len, args.len())
         }
 
-        mods.truncate(prev_mods_len);
+        mods.truncate(orig_mods_len);
-
+        state.rewind_fn_resolution_caches(orig_fn_resolution_caches_len);
-        if is_unified {
-            state.pop_fn_resolution_cache();
-        }
 
         result
     }
@@ -879,7 +881,7 @@ impl Engine {
         )?;
 
         // If new functions are defined within the eval string, it is an error
-        if ast.lib().count().0 != 0 {
+        if !ast.lib().is_empty() {
             return Err(ParseErrorType::WrongFnDefinition.into());
         }
 
@@ -1225,7 +1227,7 @@ impl Engine {
             // Handle eval()
             KEYWORD_EVAL if total_args == 1 => {
                 // eval - only in function call style
-                let prev_len = scope.len();
+                let orig_scope_len = scope.len();
                 let (value, pos) = self.get_arg_value(
                     scope, mods, state, lib, this_ptr, level, &a_expr[0], constants,
                 )?;
@@ -1237,7 +1239,7 @@ impl Engine {
 
                 // IMPORTANT! If the eval defines new variables in the current scope,
                 //            all variable offsets from this point on will be mis-aligned.
-                if scope.len() != prev_len {
+                if scope.len() != orig_scope_len {
                     state.always_search_scope = true;
                 }
 

src/lib.rs

@@ -129,27 +129,14 @@ pub use types::{
 /// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most
 /// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline.
 #[cfg(not(feature = "internals"))]
-#[cfg(not(feature = "no_smartstring"))]
 pub(crate) type Identifier = SmartString;
 
-/// An identifier in Rhai.
-#[cfg(not(feature = "internals"))]
-#[cfg(feature = "no_smartstring")]
-pub(crate) type Identifier = ImmutableString;
-
 /// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most
 /// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline.
 #[cfg(feature = "internals")]
-#[cfg(not(feature = "no_smartstring"))]
 #[deprecated = "this type is volatile and may change"]
 pub type Identifier = SmartString;
 
-/// An identifier in Rhai.
-#[cfg(feature = "internals")]
-#[cfg(feature = "no_smartstring")]
-#[deprecated = "this type is volatile and may change"]
-pub type Identifier = ImmutableString;
-
 /// Alias to [`Rc`][std::rc::Rc] or [`Arc`][std::sync::Arc] depending on the `sync` feature flag.
 pub use func::Shared;
 
@@ -314,12 +301,8 @@ type StaticVec<T> = smallvec::SmallVec<[T; 3]>;
 #[cfg(feature = "internals")]
 pub type StaticVec<T> = smallvec::SmallVec<[T; 3]>;
 
-#[cfg(not(feature = "no_smartstring"))]
 pub(crate) type SmartString = smartstring::SmartString<smartstring::LazyCompact>;
 
-#[cfg(feature = "no_smartstring")]
-pub(crate) type SmartString = String;
-
 // Compiler guards against mutually-exclusive feature flags
 
 #[cfg(feature = "no_float")]

src/module/mod.rs

@@ -324,7 +324,9 @@ impl Module {
     #[inline]
     #[must_use]
     pub fn is_empty(&self) -> bool {
-        self.functions.is_empty()
+        self.indexed
+            && !self.contains_indexed_global_functions
+            && self.functions.is_empty()
             && self.all_functions.is_empty()
             && self.variables.is_empty()
             && self.all_variables.is_empty()
@@ -502,11 +504,15 @@ impl Module {
         name: &str,
         num_params: usize,
     ) -> Option<&Shared<crate::ast::ScriptFnDef>> {
+        if self.functions.is_empty() {
+            None
+        } else {
             self.functions
                 .values()
                 .find(|f| f.params == num_params && f.name == name)
                 .and_then(|f| f.func.get_script_fn_def())
         }
+    }
 
     /// Get a mutable reference to the underlying [`BTreeMap`] of sub-modules.
     ///
@@ -1150,6 +1156,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers += other.identifiers;
         self
     }
 
@@ -1169,6 +1176,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers += other.identifiers;
         self
     }
 
@@ -1197,6 +1205,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers.merge(&other.identifiers);
         self
     }
 
@@ -1246,6 +1255,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers.merge(&other.identifiers);
         self
     }
 
@@ -1454,6 +1464,7 @@ impl Module {
 
         // Non-private functions defined become module functions
         #[cfg(not(feature = "no_function"))]
+        if !ast.lib().functions.is_empty() {
             ast.lib()
                 .functions
                 .values()
@@ -1474,6 +1485,7 @@ impl Module {
                     func.mods = func_mods.clone();
                     module.set_script_fn(func);
                 });
+        }
 
         if let Some(s) = ast.source_raw() {
             module.set_id(s.clone());

src/parser.rs

@@ -23,6 +23,7 @@ use std::{
     collections::BTreeMap,
     hash::{Hash, Hasher},
     num::{NonZeroU8, NonZeroUsize},
+    ops::AddAssign,
 };
 
 #[cfg(not(feature = "no_float"))]
@@ -51,39 +52,29 @@ const NEVER_ENDS: &str = "`TokenStream` never ends";
 /// collection of strings and returns shared instances, only creating a new string when it is not
 /// yet interned.
 #[derive(Debug, Clone, Hash)]
-pub struct IdentifierBuilder(
+pub struct IdentifierBuilder();
-    #[cfg(feature = "no_smartstring")] std::collections::BTreeSet<Identifier>,
-);
 
 impl IdentifierBuilder {
-    /// Create a new IdentifierBuilder.
+    /// Create a new [`IdentifierBuilder`].
-    #[cfg(not(feature = "no_smartstring"))]
     #[inline]
     #[must_use]
     pub const fn new() -> Self {
         Self()
     }
-    /// Create a new IdentifierBuilder.
-    #[cfg(feature = "no_smartstring")]
-    #[inline]
-    #[must_use]
-    pub fn new() -> Self {
-        Self(std::collections::BTreeSet::new())
-    }
     /// Get an identifier from a text string.
     #[inline]
     #[must_use]
     pub fn get(&mut self, text: impl AsRef<str> + Into<Identifier>) -> Identifier {
-        #[cfg(not(feature = "no_smartstring"))]
+        text.into()
-        return text.into();
-
-        #[cfg(feature = "no_smartstring")]
-        return self.0.get(text.as_ref()).cloned().unwrap_or_else(|| {
-            let s: Identifier = text.into();
-            self.0.insert(s.clone());
-            s
-        });
     }
+    /// Merge another [`IdentifierBuilder`] into this.
+    #[inline(always)]
+    pub fn merge(&mut self, _other: &Self) {}
+}
+
+impl AddAssign for IdentifierBuilder {
+    #[inline(always)]
+    fn add_assign(&mut self, _rhs: Self) {}
 }
 
 /// _(internals)_ A type that encapsulates the current state of the parser.

src/tests.rs

@@ -21,14 +21,7 @@ fn check_struct_sizes() {
     assert_eq!(size_of::<Option<ast::Expr>>(), 16);
     assert_eq!(size_of::<ast::Stmt>(), 32);
     assert_eq!(size_of::<Option<ast::Stmt>>(), 32);
-    assert_eq!(
+    assert_eq!(size_of::<FnPtr>(), 80);
-        size_of::<FnPtr>(),
-        if cfg!(feature = "no_smartstring") {
-            64
-        } else {
-            80
-        }
-    );
     assert_eq!(size_of::<Scope>(), 464);
     assert_eq!(size_of::<LexError>(), 56);
     assert_eq!(

src/types/fn_ptr.rs

@@ -153,7 +153,6 @@ impl TryFrom<Identifier> for FnPtr {
     }
 }
 
-#[cfg(not(feature = "no_smartstring"))]
 impl TryFrom<crate::ImmutableString> for FnPtr {
     type Error = Box<EvalAltResult>;
 

src/types/immutable_string.rs

@@ -115,14 +115,12 @@ impl From<String> for ImmutableString {
         Self(value.into())
     }
 }
-#[cfg(not(feature = "no_smartstring"))]
 impl From<&SmartString> for ImmutableString {
     #[inline(always)]
     fn from(value: &SmartString) -> Self {
         Self(value.clone().into())
     }
 }
-#[cfg(not(feature = "no_smartstring"))]
 impl From<SmartString> for ImmutableString {
     #[inline(always)]
     fn from(value: SmartString) -> Self {
@@ -180,7 +178,6 @@ impl<'a> FromIterator<String> for ImmutableString {
     }
 }
 
-#[cfg(not(feature = "no_smartstring"))]
 impl<'a> FromIterator<SmartString> for ImmutableString {
     #[inline]
     fn from_iter<T: IntoIterator<Item = SmartString>>(iter: T) -> Self {