this code is a mess and I am losing my mind

This commit does not work and I am so down I don't even bother
committing to conventional commits until I fix this mess.

furvm/include/furvm/fwd.hpp

@@ -111,7 +111,7 @@ using function_id = std::uint16_t;
 /**
  * @brief A handle to a furvm function.
  */
-using function_h = handle<function, refcount_header<function_id>>;
+using function_h = handle<function, generic_header<function_id>>;
 
 // module.hpp
 

furvm/include/furvm/instruction.hpp

@@ -76,6 +76,11 @@ enum class instruction_t : byte {
      */
     Duplicate,
 
+    /**
+     * @brief Swaps two top elements of the stack.
+     */
+    Swap,
+
     /**
      * @brief Clones top element on the stack.
      */

furvm/include/furvm/thing.hpp

@@ -502,6 +502,32 @@ public:
         if (m_type.type != thing_type::Ref || *m_type.value.typeRef != thing.type()) throw bad_thing_access();
         m_data = thing.m_data;
     }
+
+    /**
+     * @brief Self-explainatory.
+     *
+     * TODO: Document
+     */
+    void assign(thing&& thing) {
+        class thing rhs = std::move(thing);
+        if (true_type() != rhs.true_type()) throw std::runtime_error("thing type mismatch");
+        // TODO: Move this to another function
+        switch (true_type().type) {
+        case thing_type::S8:
+        case thing_type::S16:
+        case thing_type::S32:
+        case thing_type::S64:
+        case thing_type::U8:
+        case thing_type::U16:
+        case thing_type::U32:
+        case thing_type::U64: std::memcpy(m_data, rhs.m_data, m_size); return;
+        case thing_type::Ptr:
+        case thing_type::Ref:
+        case thing_type::Array: throw std::runtime_error("unimplemented");
+        case thing_type::Count: break;
+        }
+        throw std::runtime_error("unreachable");
+    }
 private:
     static void copy_list(const thing_type& arrayType, array& dst, const array& src) {
         if (arrayType.type != thing_type::Array || arrayType.value.array.type == nullptr)

furvm/src/executor.cpp

@@ -10,6 +10,7 @@
 #include <cassert>
 #include <cstdint>
 #include <stdexcept>
+#include <utility>
 #include <vector>
 
 namespace furvm {
@@ -122,7 +123,7 @@ void executor::store_thing(variable_t variable, thing_h&& thing) {
 
 thing_h executor::load_thing(variable_t variable) const {
     const auto& frame = m_frames.top();
-    return frame.variables[variable];
+    return { frame.variables[variable] };
 }
 
 void executor::step() {
@@ -186,10 +187,10 @@ void executor::step() {
         push_thing(array->at(index->integer()));
     } break;
     case instruction_t::Set: {
-        auto index                  = pop_thing();
-        auto array                  = pop_thing();
-        auto element                = pop_thing();
-        array->at(index->integer()) = std::move(element->clone());
+        auto element = pop_thing();
+        auto index   = pop_thing();
+        auto array   = pop_thing();
+        array->at(index->integer()).assign(std::move(element->clone()));
     } break;
     case instruction_t::Drop: {
         pop_thing();
@@ -197,6 +198,12 @@ void executor::step() {
     case instruction_t::Duplicate: {
         push_thing(thing());
     } break;
+    case instruction_t::Swap: {
+        auto thing1 = pop_thing();
+        auto thing2 = pop_thing();
+        push_thing(std::move(thing1));
+        push_thing(std::move(thing2));
+    } break;
     case instruction_t::Clone: {
         push_thing(std::move(thing()->clone()));
     } break;
@@ -316,7 +323,8 @@ void executor::step() {
         push_frame(frame.mod, *frame.mod->function_at(funcId));
     } break;
     case instruction_t::Jump: {
-        frame.position += ((std::int8_t)frame.mod->byte(frame.position)) + 1;
+        std::int8_t offset = static_cast<std::int8_t>(frame.mod->byte(frame.position++));
+        frame.position    += offset;
     } break;
     case instruction_t::JumpNotZero: {
         byte offset = frame.mod->byte(frame.position++);

furvm/src/main.cpp

@@ -75,8 +75,8 @@ int main(int argc, char** argv) {
     mod->emplace_function(furvm::function_sig{ { u64Type }, u64Type }, "print").dispatch();
 #endif
     mod->set_native_function("println", [](furvm::executor& executor) {
-        auto arg = std::move(*executor.load_thing(0));
-        print_thing(arg);
+        auto arg = executor.load_thing(0);
+        print_thing(*arg);
         std::cout << '\n';
     });