diff --git a/src/eval/expr.rs b/src/eval/expr.rs
index 7fd7027b..251032cd 100644
--- a/src/eval/expr.rs
+++ b/src/eval/expr.rs
@@ -242,17 +242,57 @@ impl Engine {
 
             let arg_values = &mut [&mut lhs, &mut rhs];
 
-            return if let Some(f) =
-                crate::func::get_builtin_binary_op_fn(&name, arg_values[0], arg_values[1])
-            {
-                let context = (self, name, None, &*global, lib, pos, level).into();
-                (f)(context, arg_values)
+            let hash = crate::func::combine_hashes(
+                hashes.native,
+                crate::func::calc_fn_params_hash(arg_values.iter().map(|a| a.type_id())),
+            );
+
+            let c = caches.fn_resolution_cache_mut();
+
+            let entry = if c.contains_key(&hash) {
+                match c.get(&hash).unwrap() {
+                    Some(entry) => entry,
+                    None => {
+                        return Err(ERR::ErrorFunctionNotFound(
+                            self.gen_fn_call_signature(
+                                #[cfg(not(feature = "no_module"))]
+                                &crate::ast::Namespace::NONE,
+                                name,
+                                arg_values,
+                            ),
+                            pos,
+                        )
+                        .into())
+                    }
+                }
             } else {
-                self.exec_fn_call(
-                    None, global, caches, lib, name, *hashes, arg_values, false, false, pos, level,
-                )
-                .map(|(v, ..)| v)
+                match crate::func::get_builtin_binary_op_fn(&name, arg_values[0], arg_values[1]) {
+                    Some(f) => {
+                        let entry = crate::eval::FnResolutionCacheEntry {
+                            func: crate::func::CallableFunction::from_method(
+                                Box::new(f) as Box<crate::func::FnAny>
+                            ),
+                            source: None,
+                        };
+                        c.insert(hash, Some(entry));
+                        c.get(&hash).unwrap().as_ref().unwrap()
+                    }
+                    None => {
+                        println!("Exec {name} with {:?}", arg_values);
+                        return self
+                            .exec_fn_call(
+                                None, global, caches, lib, name, *hashes, arg_values, false, false,
+                                pos, level,
+                            )
+                            .map(|(v, ..)| v);
+                    }
+                }
             };
+
+            let func = entry.func.get_native_fn().unwrap();
+            let context = (self, name, None, &*global, lib, pos, level).into();
+            let result = (func)(context, arg_values);
+            return self.check_return_value(result, pos);
         }
 
         #[cfg(not(feature = "no_module"))]
diff --git a/src/func/call.rs b/src/func/call.rs
index 4b1696d8..2662cc80 100644
--- a/src/func/call.rs
+++ b/src/func/call.rs
@@ -131,7 +131,7 @@ impl Engine {
     /// Generate the signature for a function call.
     #[inline]
     #[must_use]
-    fn gen_call_signature(
+    pub(crate) fn gen_fn_call_signature(
         &self,
         #[cfg(not(feature = "no_module"))] namespace: &crate::ast::Namespace,
         fn_name: &str,
@@ -174,26 +174,26 @@ impl Engine {
     fn resolve_fn<'s>(
         &self,
         _global: &GlobalRuntimeState,
-        state: &'s mut Caches,
+        caches: &'s mut Caches,
         lib: &[&Module],
         fn_name: &str,
-        hash_script: u64,
+        hash_base: u64,
         args: Option<&mut FnCallArgs>,
         allow_dynamic: bool,
         is_op_assignment: bool,
     ) -> Option<&'s FnResolutionCacheEntry> {
-        if hash_script == 0 {
+        if hash_base == 0 {
             return None;
         }
 
-        let mut hash = args.as_ref().map_or(hash_script, |args| {
+        let mut hash = args.as_ref().map_or(hash_base, |args| {
             combine_hashes(
-                hash_script,
+                hash_base,
                 calc_fn_params_hash(args.iter().map(|a| a.type_id())),
             )
         });
 
-        let result = state
+        let result = caches
             .fn_resolution_cache_mut()
             .entry(hash)
             .or_insert_with(|| {
@@ -248,21 +248,21 @@ impl Engine {
 
                     // Check `Dynamic` parameters for functions with parameters
                     if allow_dynamic && max_bitmask == 0 && num_args > 0 {
-                        let is_dynamic = lib.iter().any(|&m| m.contains_dynamic_fn(hash_script))
+                        let is_dynamic = lib.iter().any(|&m| m.contains_dynamic_fn(hash_base))
                             || self
                                 .global_modules
                                 .iter()
-                                .any(|m| m.contains_dynamic_fn(hash_script));
+                                .any(|m| m.contains_dynamic_fn(hash_base));
 
                         #[cfg(not(feature = "no_module"))]
                         let is_dynamic = is_dynamic
                             || _global
                                 .iter_imports_raw()
-                                .any(|(_, m)| m.contains_dynamic_fn(hash_script))
+                                .any(|(_, m)| m.contains_dynamic_fn(hash_base))
                             || self
                                 .global_sub_modules
                                 .values()
-                                .any(|m| m.contains_dynamic_fn(hash_script));
+                                .any(|m| m.contains_dynamic_fn(hash_base));
 
                         // Set maximum bitmask when there are dynamic versions of the function
                         if is_dynamic {
@@ -317,7 +317,7 @@ impl Engine {
                                 }
                             }),
                     );
-                    hash = combine_hashes(hash_script, hash_params);
+                    hash = combine_hashes(hash_base, hash_params);
 
                     bitmask += 1;
                 }
@@ -542,7 +542,7 @@ impl Engine {
 
             // Raise error
             _ => Err(ERR::ErrorFunctionNotFound(
-                self.gen_call_signature(
+                self.gen_fn_call_signature(
                     #[cfg(not(feature = "no_module"))]
                     &crate::ast::Namespace::NONE,
                     name,
@@ -1429,7 +1429,7 @@ impl Engine {
             Some(f) => unreachable!("unknown function type: {:?}", f),
 
             None => Err(ERR::ErrorFunctionNotFound(
-                self.gen_call_signature(namespace, fn_name, &args),
+                self.gen_fn_call_signature(namespace, fn_name, &args),
                 pos,
             )
             .into()),
diff --git a/src/packages/array_basic.rs b/src/packages/array_basic.rs
index 0751a768..21abbde9 100644
--- a/src/packages/array_basic.rs
+++ b/src/packages/array_basic.rs
@@ -123,7 +123,7 @@ pub mod array_functions {
     /// let x = [1, 2, 3];
     /// let y = [true, 'x'];
     ///
-    /// x.push(y);
+    /// x.append(y);
     ///
     /// print(x);       // prints "[1, 2, 3, true, 'x']"
     /// ```