feat: introduce array and get instruction

furvm/include/furvm/instruction.hpp

@@ -25,6 +25,19 @@ enum class instruction_t : byte {
      */
     PushConstant,
 
+    /**
+     * @brief Pushes a new array onto the stack.
+     *
+     * Type is the next 4 bytes in little-endian.
+     * If the type is dynamic the array's size will be popped off of the stack.
+     */
+    Array,
+
+    /**
+     * @brief Pushes an element from an array onto the stack.
+     */
+    Get,
+
     /**
      * @brief Pops top element from the stack.
      */

furvm/include/furvm/thing.hpp

@@ -283,24 +283,39 @@ public:
         if (m_type->t != type_t::Array) throw bad_thing_access();
         if (m_type->array.size > 0) throw std::runtime_error("cannot resize a static array");
 
-        auto& list = get<array_t>();
+        auto& array = get<array_t>();
-        if (newSize < 0 || newSize == list.size) return;
+        if (newSize < 0 || newSize == array.dynamic.size) return;
         std::size_t innerSize = compute_size_na(*m_type->array.type);
         std::byte*  newData   = new std::byte[innerSize * newSize];
-        std::memcpy(newData, list.data, innerSize * std::min(list.size, newSize));
+        std::memcpy(newData, array.dynamic.data, innerSize * std::min(array.dynamic.size, newSize));
-        list.size = newSize;
+        array.dynamic.size = newSize;
-        delete[] list.data;
+        delete[] array.dynamic.data;
-        list.data = newData;
+        array.dynamic.data = newData;
     }
 
     thing at(long_t index) const {
         if (m_type->t != type_t::Array) throw bad_thing_access();
-        auto& list = get<array_t>();
+
-        if (index < 0 || index >= list.size) throw std::out_of_range("index out of range");
+        std::size_t elementSize = compute_size_na(*m_type->array.type);
-        thing res              = { std::make_shared<type>(m_type->array.type), m_modules, m_allocator };
+        thing       res         = { std::make_shared<class type>(*m_type->array.type), m_modules, m_allocator };
-        res.get<reference_t>() = list.data; // TODO: Account for padding, alignment and stuff
+        if (m_type->array.size == 0) {
+            auto& array = get<array_t>();
+            if (index < 0 || index >= array.dynamic.size) throw std::out_of_range("index out of range");
+            res.get<reference_t>() = array.dynamic.data + (index * elementSize);
             return std::move(res);
         }
+
+        std::byte* data = reinterpret_cast<array_t*>(m_data)->data;
+        if (index < 0 || index >= m_type->array.size) throw std::out_of_range("index out of range");
+        res.get<reference_t>() = data + (index * elementSize);
+        return std::move(res);
+    }
+
+    std::size_t size() const {
+        if (m_type->t != type_t::Array) throw std::runtime_error("not an array");
+        if (m_type->array.size == 0) return get<array_t>().dynamic.size;
+        return m_type->array.size;
+    }
 public:
     static type_p resolve_type(const type_p& initType, const mod_container& modules) {
         type_p rsv = initType;

furvm/src/executor.cpp

@@ -6,6 +6,7 @@
 #include "furvm/fwd.hpp"
 #include "furvm/instruction.hpp"
 #include "furvm/thing.hpp"
+#include "furvm/type.hpp"
 
 #include <cstdint>
 #include <stdexcept>
@@ -94,6 +95,32 @@ void executor::step() {
         push_thing({ *m_context->at("core")->type_at(2), m_context, m_context->thing_alloc() })->get<int_t>() =
             frame.mod->byte(frame.position++);
     } break;
+    case instruction_t::Array: {
+        type_id typeId  = static_cast<type_id>(frame.mod->byte(frame.position)) |
+                          (static_cast<type_id>(frame.mod->byte(frame.position + 1)) << 8) |
+                          (static_cast<type_id>(frame.mod->byte(frame.position + 2)) << 16) |
+                          (static_cast<type_id>(frame.mod->byte(frame.position + 3)) << 24);
+        frame.position += 4;
+
+        auto type = furvm::thing<>::resolve_type(*frame.mod->type_at(typeId), m_context);
+        if (type == nullptr || type->t != type_t::Array || *type->array.type == nullptr)
+            throw std::runtime_error("invalid array type");
+
+        auto array = push_thing({ type, m_context, m_context->thing_alloc() });
+
+        if (type->array.size == 0) {
+            auto   sizeThing = pop_thing();
+            long_t size      = sizeThing->integer();
+            array->resize(size);
+        }
+
+        push_thing(std::move(array));
+    } break;
+    case instruction_t::Get: {
+        auto index = pop_thing();
+        auto array = pop_thing();
+        push_thing(array->at(index->integer()));
+    } break;
     case instruction_t::Drop: {
         pop_thing();
     } break;

furvm/src/main.cpp

@@ -10,13 +10,33 @@
 #include <memory>
 #include <sstream>
 
+static void print_thing(const furvm::thing<furvm::thing_allocator>& thing) {
+    auto rsv = thing.resolve();
+    switch (rsv.type()->t) {
+    case furvm::type_t::Primitive: {
+        std::cout << rsv.integer();
+    } break;
+    case furvm::type_t::Array: {
+        std::cout << "{ ";
+        for (furvm::long_t i = 0; i < rsv.size(); ++i) {
+            if (i > 0) std::cout << ", ";
+            print_thing(rsv.at(i));
+        }
+        std::cout << " }\n";
+    } break;
+    default: std::cerr << "{Something went wrong}";
+    }
+}
+
 int main(int argc, char** argv) {
+    auto context = std::make_shared<furvm::context>();
+
+#if 0 // NOLINT
     if (argc != 2) {
         std::cerr << "Usage: " << argv[0] << " <mod.fmod>\n";
         return 1;
     }
 
-    auto context = std::make_shared<furvm::context>();
 
     std::ifstream file(argv[1]);
     if (!file.is_open()) {
@@ -24,14 +44,29 @@ int main(int argc, char** argv) {
         return 1;
     }
 
-    furvm::mod_h      mod  = context->emplace("main", furvm::mod::load(file));
+    furvm::mod_h mod = context->emplace("main", std::move(furvm::mod::load(file)));
-    furvm::function_h func = mod->function_at("main");
+#else
+    static const furvm::byte s_bytecode[] = {
+        static_cast<furvm::byte>(furvm::instruction_t::Array),
+        0,
+        0,
+        0,
+        0,
+        static_cast<furvm::byte>(furvm::instruction_t::Call),
+        1,
+        0,
+        static_cast<furvm::byte>(furvm::instruction_t::Return),
+    };
 
-    mod->set_native_function("print",
+    furvm::mod_h mod = context->emplace("main", s_bytecode, s_bytecode + sizeof(s_bytecode));
-        [](furvm::executor& executor) { std::cout << executor.load_thing(0)->integer() << '\n'; });
+    mod->emplace_type(std::make_shared<furvm::type>(context->at("core")->type_at(2), 10)).dispatch();
+    auto mainFunc = mod->emplace_function("main", 0, 0);
+    mod->emplace_function_private("print", 1, "print").dispatch();
+#endif
+    mod->set_native_function("print", [](furvm::executor& executor) { print_thing(*executor.load_thing(0)); });
 
     furvm::executor_h executor = context->emplace_executor(context);
-    executor->push_frame(mod, *func);
+    executor->push_frame(mod, *mainFunc);
 
     while ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done) {
         executor->step();