From 6ec4710eaa349397315399c6183d43fcb99219ed Mon Sep 17 00:00:00 2001
From: CHatingPython <chatingpython@kpgpmc.org>
Date: Wed, 1 Jul 2026 21:58:33 +0200
Subject: [PATCH] feat: introduce reference instruction

---
 furvm/include/furvm/instruction.hpp | 7 +++++++
 furvm/include/furvm/thing.hpp       | 2 +-
 furvm/src/executor.cpp              | 4 ++++
 furvm/src/main.cpp                  | 5 +++--
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/furvm/include/furvm/instruction.hpp b/furvm/include/furvm/instruction.hpp
index fa4e44b..b728a9a 100644
--- a/furvm/include/furvm/instruction.hpp
+++ b/furvm/include/furvm/instruction.hpp
@@ -40,6 +40,13 @@ enum class instruction_t : byte {
      */
     Clone,
 
+    /**
+     * @brief Pushes a new reference onto the stack.
+     *
+     * Pops the top thing from the stack and pushes its reference.
+     */
+    Reference,
+
     /**
      * @brief Adds two things together on the stack.
      */
diff --git a/furvm/include/furvm/thing.hpp b/furvm/include/furvm/thing.hpp
index 17d0afd..3e65943 100644
--- a/furvm/include/furvm/thing.hpp
+++ b/furvm/include/furvm/thing.hpp
@@ -368,7 +368,7 @@ public:
     }
 
     thing reference() const {
-        thing res              = { std::make_shared<type>({ m_type }), m_allocator };
+        thing res              = { std::make_shared<class type>(m_type), m_allocator };
         res.get<reference_t>() = m_data;
         return std::move(res);
     }
diff --git a/furvm/src/executor.cpp b/furvm/src/executor.cpp
index fe61fef..07c6ba2 100644
--- a/furvm/src/executor.cpp
+++ b/furvm/src/executor.cpp
@@ -102,6 +102,10 @@ void executor::step() {
     case instruction_t::Clone: {
         push_thing(std::move(thing()->clone()));
     } break;
+    case instruction_t::Reference: {
+        auto thing = pop_thing();
+        push_thing(std::move(thing->reference()));
+    } break;
     case instruction_t::Add: {
         auto rhs = pop_thing();
         auto lhs = pop_thing();
diff --git a/furvm/src/main.cpp b/furvm/src/main.cpp
index 2b1973e..715992c 100644
--- a/furvm/src/main.cpp
+++ b/furvm/src/main.cpp
@@ -8,10 +8,11 @@
 #include <iostream>
 #include <memory>
 
-static constexpr std::array<furvm::byte, 8> s_bytecode = {
+static constexpr std::array<furvm::byte, 9> s_bytecode = {
     furvm::byte(furvm::instruction_t::PushB2I),
     67,
-    furvm::byte(furvm::instruction_t::Clone),
+    furvm::byte(furvm::instruction_t::Duplicate),
+    furvm::byte(furvm::instruction_t::Reference),
     furvm::byte(furvm::instruction_t::Add),
     furvm::byte(furvm::instruction_t::Call),
     1,