diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5913e007..5d3cf23b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,16 +4,22 @@ Rhai Release Notes
 Version 1.13.0
 ==============
 
+This version attempts a number of optimizations that may yield small speed improvements:
+
+* Simple operators (e.g. integer arithmetic) are inlined to avoid the overhead of a function call.
+* The tokenizer uses pre-calculated tables (generated by GNU `gperf`) for keyword recognition.
+* A black-arts trick (see `Engine::black_box`) is used to prevent LLVM from optimizing hand-tuned AST node matches back into a lookup table, which messes up branch prediction on modern CPU's.
+
 Bug fixes
 ---------
 
 * Complex indexing/dotting chains now parse correctly, for example: `a[b][c[d]].e`
 * `map` and `filter` for arrays are marked `pure`. Warnings are added to the documentation of pure array methods that take `this` closures.
 * Syntax such as `foo.bar::baz` no longer panics, but returns a proper parse error.
-* `x += y` where `x` and `y` are `char` now works correctly.
 * Expressions such as `!inside` now parses correctly instead of as `!in` followed by `side`.
 * Custom syntax starting with symbols now works correctly and no longer raises a parse error.
 * Comparing different custom types now works correctly when the appropriate comparison operators are registered.
+* Some op-assignments, such as `x += y` where `x` and `y` are `char`, now work correctly instead of failing silently.
 * Op-assignments to bit flags or bit ranges now work correctly.
 
 Potentially breaking changes
@@ -30,8 +36,9 @@ Enhancements
 * The functions `min` and `max` are added for numbers.
 * Range cases in `switch` statements now also match floating-point and decimal values. In order to support this, however, small numeric ranges cases are no longer unrolled.
 * Loading a module via `import` now gives the module access to the current scope, including variables and constants defined inside.
-* Some very simple operator calls (e.g. integer add) are short-circuited to avoid the overhead of a function call, resulting in a small speed improvement.
-* The tokenizer now uses table-driven keyword recognizers generated by GNU gperf. At least _theoretically_ it should be faster...
+* Some very simple operator calls (e.g. integer add) are inlined to avoid the overhead of a function call, resulting in a small speed improvement.
+* The tokenizer now uses table-driven keyword recognizers generated by GNU `gperf`. At least _theoretically_ it should be faster...
+* The field `isAnonymous` is added to JSON functions metadata.
 
 
 Version 1.12.0
diff --git a/src/api/eval.rs b/src/api/eval.rs
index 3882fae5..2c93b182 100644
--- a/src/api/eval.rs
+++ b/src/api/eval.rs
@@ -242,7 +242,7 @@ impl Engine {
             ast.resolver().cloned(),
         );
 
-        auto_restore!(global => move |g| {
+        auto_restore! { global => move |g| {
             #[cfg(not(feature = "no_module"))]
             {
                 g.embedded_module_resolver = orig_embedded_module_resolver;
@@ -252,7 +252,7 @@ impl Engine {
             g.lib.truncate(orig_lib_len);
 
             g.source = orig_source;
-        });
+        }}
 
         let r = self.eval_global_statements(global, caches, scope, ast.statements())?;
 
diff --git a/src/eval/chaining.rs b/src/eval/chaining.rs
index 22e8ae46..a6184061 100644
--- a/src/eval/chaining.rs
+++ b/src/eval/chaining.rs
@@ -688,7 +688,7 @@ impl Engine {
                         let reset =
                             self.run_debugger_with_reset(global, caches, scope, this_ptr, rhs)?;
                         #[cfg(feature = "debugging")]
-                        auto_restore!(global if Some(reset) => move |g| g.debugger_mut().reset_status(reset));
+                        auto_restore! { global if Some(reset) => move |g| g.debugger_mut().reset_status(reset) }
 
                         let crate::ast::FnCallExpr {
                             name, hashes, args, ..
@@ -857,7 +857,7 @@ impl Engine {
                                 let reset = self
                                     .run_debugger_with_reset(global, caches, scope, _tp, _node)?;
                                 #[cfg(feature = "debugging")]
-                                auto_restore!(global if Some(reset) => move |g| g.debugger_mut().reset_status(reset));
+                                auto_restore! { global if Some(reset) => move |g| g.debugger_mut().reset_status(reset) }
 
                                 let crate::ast::FnCallExpr {
                                     name, hashes, args, ..
@@ -977,7 +977,7 @@ impl Engine {
                                         global, caches, scope, _tp, _node,
                                     )?;
                                     #[cfg(feature = "debugging")]
-                                    auto_restore!(global if Some(reset) => move |g| g.debugger_mut().reset_status(reset));
+                                    auto_restore! { global if Some(reset) => move |g| g.debugger_mut().reset_status(reset) }
 
                                     let crate::ast::FnCallExpr {
                                         name, hashes, args, ..
diff --git a/src/eval/expr.rs b/src/eval/expr.rs
index c2aaf79d..f73bd496 100644
--- a/src/eval/expr.rs
+++ b/src/eval/expr.rs
@@ -243,7 +243,7 @@ impl Engine {
         let reset =
             self.run_debugger_with_reset(global, caches, scope, this_ptr.as_deref_mut(), expr)?;
         #[cfg(feature = "debugging")]
-        auto_restore!(global if Some(reset) => move |g| g.debugger_mut().reset_status(reset));
+        auto_restore! { global if Some(reset) => move |g| g.debugger_mut().reset_status(reset) }
 
         self.track_operation(global, expr.position())?;
 
diff --git a/src/eval/stmt.rs b/src/eval/stmt.rs
index 1f4ae51d..799846b3 100644
--- a/src/eval/stmt.rs
+++ b/src/eval/stmt.rs
@@ -54,7 +54,7 @@ impl Engine {
             global.scope_level += 1;
         }
 
-        auto_restore!(global if restore_orig_state => move |g| {
+        auto_restore! { global if restore_orig_state => move |g| {
             g.scope_level -= 1;
 
             #[cfg(not(feature = "no_module"))]
@@ -63,7 +63,7 @@ impl Engine {
             // The impact of new local variables goes away at the end of a block
             // because any new variables introduced will go out of scope
             g.always_search_scope = orig_always_search_scope;
-        });
+        }}
 
         // Pop new function resolution caches at end of block
         auto_restore! {
@@ -271,7 +271,7 @@ impl Engine {
         let reset =
             self.run_debugger_with_reset(global, caches, scope, this_ptr.as_deref_mut(), stmt)?;
         #[cfg(feature = "debugging")]
-        auto_restore!(global if Some(reset) => move |g| g.debugger_mut().reset_status(reset));
+        auto_restore! { global if Some(reset) => move |g| g.debugger_mut().reset_status(reset) }
 
         self.track_operation(global, stmt.position())?;
 
diff --git a/src/func/call.rs b/src/func/call.rs
index 079c095b..886cdd75 100644
--- a/src/func/call.rs
+++ b/src/func/call.rs
@@ -658,7 +658,7 @@ impl Engine {
                 };
 
                 let orig_source = mem::replace(&mut global.source, source.clone());
-                auto_restore!(global => move |g| g.source = orig_source);
+                auto_restore! { global => move |g| g.source = orig_source }
 
                 return if _is_method_call {
                     // Method call of script function - map first argument to `this`
@@ -686,7 +686,7 @@ impl Engine {
                         backup.change_first_arg_to_copy(_args);
                     }
 
-                    auto_restore!(args = (_args) if swap => move |a| backup.restore_first_arg(a));
+                    auto_restore! { args = (_args) if swap => move |a| backup.restore_first_arg(a) }
 
                     self.call_script_fn(global, caches, scope, None, environ, f, args, true, pos)
                 }
@@ -730,7 +730,7 @@ impl Engine {
             })
         });
         #[cfg(feature = "debugging")]
-        auto_restore!(global if Some(reset) => move |g| g.debugger_mut().reset_status(reset));
+        auto_restore! { global if Some(reset) => move |g| g.debugger_mut().reset_status(reset) }
 
         self.eval_expr(global, caches, scope, this_ptr, arg_expr)
             .map(|r| (r, arg_expr.start_position()))
@@ -1457,7 +1457,7 @@ impl Engine {
                 let scope = &mut Scope::new();
 
                 let orig_source = mem::replace(&mut global.source, module.id_raw().cloned());
-                auto_restore!(global => move |g| g.source = orig_source);
+                auto_restore! { global => move |g| g.source = orig_source }
 
                 self.call_script_fn(global, caches, scope, None, environ, f, args, true, pos)
             }
diff --git a/src/serde/metadata.rs b/src/serde/metadata.rs
index fa41fd6b..e207ee29 100644
--- a/src/serde/metadata.rs
+++ b/src/serde/metadata.rs
@@ -34,6 +34,8 @@ struct FnMetadata<'a> {
     pub namespace: crate::FnNamespace,
     pub access: FnAccess,
     pub name: &'a str,
+    #[cfg(not(feature = "no_function"))]
+    pub is_anonymous: bool,
     #[serde(rename = "type")]
     pub typ: FnType,
     pub num_params: usize,
@@ -83,6 +85,8 @@ impl<'a> From<&'a FuncInfo> for FnMetadata<'a> {
             namespace: info.metadata.namespace,
             access: info.metadata.access,
             name: &info.metadata.name,
+            #[cfg(not(feature = "no_function"))]
+            is_anonymous: crate::parser::is_anonymous_fn(&info.metadata.name),
             typ,
             num_params: info.metadata.num_params,
             params: info
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index 07ad2f9e..27d0cf6b 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -305,7 +305,7 @@ impl fmt::Display for Token {
     }
 }
 
-// Table-driven keyword recognizer generated by GNU gperf on the file `tools/keywords.txt`.
+// Table-driven keyword recognizer generated by GNU `gperf` on the file `tools/keywords.txt`.
 //
 // When adding new keywords, make sure to update `tools/keywords.txt` and re-generate this.
 
@@ -507,7 +507,7 @@ static KEYWORDS_LIST: [(&str, Token); 153] = [
     ("#{", Token::MapStart),
 ];
 
-// Table-driven reserved symbol recognizer generated by GNU gperf on the file `tools/reserved.txt`.
+// Table-driven reserved symbol recognizer generated by GNU `gperf` on the file `tools/reserved.txt`.
 //
 // When adding new reserved symbols, make sure to update `tools/reserved.txt` and re-generate this.
 
@@ -872,7 +872,7 @@ impl Token {
     #[must_use]
     pub fn lookup_symbol_from_syntax(syntax: &str) -> Option<Self> {
         // This implementation is based upon a pre-calculated table generated
-        // by GNU gperf on the list of keywords.
+        // by GNU `gperf` on the list of keywords.
         let utf8 = syntax.as_bytes();
         let len = utf8.len();
         let mut hash_val = len;
@@ -893,8 +893,8 @@ impl Token {
 
         match KEYWORDS_LIST[hash_val] {
             (_, Token::EOF) => None,
-            // Fail early to avoid calling memcmp()
-            // Since we are already working with bytes, mind as well check the first one
+            // Fail early to avoid calling memcmp().
+            // Since we are already working with bytes, mind as well check the first one.
             (s, ref t) if s.len() == len && s.as_bytes()[0] == utf8[0] && s == syntax => {
                 Some(t.clone())
             }
@@ -2312,7 +2312,7 @@ pub fn is_id_continue(x: char) -> bool {
 #[must_use]
 pub fn is_reserved_keyword_or_symbol(syntax: &str) -> (bool, bool, bool) {
     // This implementation is based upon a pre-calculated table generated
-    // by GNU gperf on the list of keywords.
+    // by GNU `gperf` on the list of keywords.
     let utf8 = syntax.as_bytes();
     let len = utf8.len();
     let rounds = len.min(3);
@@ -2333,8 +2333,8 @@ pub fn is_reserved_keyword_or_symbol(syntax: &str) -> (bool, bool, bool) {
     match RESERVED_LIST[hash_val] {
         ("", ..) => (false, false, false),
         (s, true, a, b) => (
-            // Fail early to avoid calling memcmp()
-            // Since we are already working with bytes, mind as well check the first one
+            // Fail early to avoid calling memcmp().
+            // Since we are already working with bytes, mind as well check the first one.
             s.len() == len && s.as_bytes()[0] == utf8[0] && s == syntax,
             a,
             b,