refactor(furvm): refactor import function

Refs: #12

furvm/include/furvm/executor.hpp

@@ -86,7 +86,7 @@ public:
      * @param mod Module.
      * @param function Function handle.
      */
-    void push_frame(const mod_h& mod, const function_h& function);
+    void push_frame(const mod_h& mod, function function);
 
     /**
      * @brief Pops the top frame.

furvm/include/furvm/function.hpp

@@ -18,31 +18,24 @@ enum class function_t : std::uint8_t {
 
 using native_function = std::function<void(executor&)>;
 
+struct import_function {
+    mod_id      mod;
+    function_id function;
+};
+
 class function {
 public:
     template <typename Name>
     function(Name&& name, bytecode_pos position)
       : m_name(std::forward<Name>(name)), m_type(function_t::Normal), m_value(position) {}
 
-    function(const char* name, bytecode_pos position)
-      : m_name(name), m_type(function_t::Normal), m_value(position) {}
-
     template <typename Name>
     function(Name&& name, const native_function& native)
       : m_name(std::forward<Name>(name)), m_type(function_t::Native), m_value(native) {}
 
-    function(const char* name, const native_function& native)
-      : m_name(name), m_type(function_t::Native), m_value(native) {}
-
-    template <typename Name, typename ModuleName>
-    function(Name&& name, ModuleName&& moduleName, function_id function)
-      : m_name(std::forward<Name>(name)),
-        m_type(function_t::Import),
-        m_value(std::forward<ModuleName>(moduleName), function) {}
-
-    template <typename ModuleName>
-    function(const char* name, ModuleName&& moduleName, function_id function)
-      : m_name(name), m_type(function_t::Import), m_value(std::forward<ModuleName>(moduleName), function) {}
+    template <typename Name>
+    function(Name&& name, const import_function& imp)
+      : m_name(std::forward<Name>(name)), m_type(function_t::Import), m_value(imp) {}
 
     ~function();
 
@@ -105,19 +98,9 @@ public:
      *
      * @return The name.
      */
-    const std::string& imported_module() const {
+    const import_function& imp() const {
         if (m_type != function_t::Import) throw std::runtime_error("function type mismatch");
-        return m_value.imp.moduleName;
-    }
-
-    /**
-     * @brief Returns a module of imported function.
-     *
-     * @return A handle to the module.
-     */
-    function_id imported_function() const {
-        if (m_type != function_t::Import) throw std::runtime_error("function type mismatch");
-        return m_value.imp.function;
+        return m_value.imp;
     }
 private:
     std::string m_name;
@@ -126,10 +109,7 @@ private:
     union value {
         std::size_t     position = 0;
         native_function native;
-        struct {
-            std::string moduleName;
-            function_id function;
-        } imp;
+        import_function imp;
 
         value() = default;
 
@@ -139,9 +119,8 @@ private:
         value(const native_function& native)
           : native(native) {}
 
-        template <typename Name>
-        value(Name&& moduleName, function_id function)
-          : imp({ std::forward<Name>(moduleName), function }) {}
+        value(const import_function& imp)
+          : imp(imp) {}
 
         ~value() {}
 

furvm/src/executor.cpp

@@ -12,9 +12,17 @@
 
 namespace furvm {
 
-void executor::push_frame(const mod_h& mod, const function_h& function) {
-    if (function->type() != function_t::Normal) throw std::runtime_error("unexpected function type");
-    m_frames.emplace((struct executor::frame){ mod, function->position(), m_stack.size() });
+void executor::push_frame(const mod_h& mod, function function) {
+    while (function.type() == function_t::Import) {
+        function = *m_context->module_at(function.imp().mod)->function_at(function.imp().function);
+    }
+    switch (function.type()) {
+    case function_t::Normal: {
+        m_frames.emplace((struct executor::frame){ mod, function.position(), m_stack.size() });
+    } break;
+    case function_t::Native:
+    default: throw std::runtime_error("unexpected function type");
+    }
 }
 
 struct executor::frame executor::pop_frame() {
@@ -155,13 +163,9 @@ void executor::step() {
 
         const function_h& function = frame.mod->function_at(funcId);
         switch (function->type()) {
-        case function_t::Normal: push_frame(frame.mod, function); break;
+        case function_t::Normal:
+        case function_t::Import: push_frame(frame.mod, *function); break;
         case function_t::Native: function->native()(*this); break;
-        case function_t::Import: {
-            // const mod_p& impMod = m_context->m_modules.at(function->imported_module());
-            // push_frame(frame.mod, function->imported_function());
-            throw std::runtime_error("unimplemented");
-        } break;
         }
     } break;
     case instruction_t::Jump: {

furvm/src/function.cpp

@@ -10,7 +10,7 @@ function::~function() {
     case function_t::Native:
     default: break;
     case function_t::Import: {
-        m_value.imp.moduleName.~basic_string();
+        m_value.imp.~import_function();
     } break;
     }
 }
@@ -25,8 +25,7 @@ function::function(function&& other) noexcept
         new (&m_value.native) native_function(std::move(other.m_value.native));
     } break;
     case function_t::Import: {
-        m_value.imp.moduleName = std::move(other.m_value.imp.moduleName);
-        m_value.imp.function   = other.m_value.imp.function;
+        m_value.imp = std::move(other.m_value.imp);
     } break;
     }
     other.m_value.position = 0;
@@ -45,8 +44,7 @@ function& function::operator=(function&& other) noexcept {
         new (&m_value.native) native_function(std::move(other.m_value.native));
     } break;
     case function_t::Import: {
-        m_value.imp.moduleName = std::move(other.m_value.imp.moduleName);
-        m_value.imp.function   = other.m_value.imp.function;
+        m_value.imp = std::move(other.m_value.imp);
     } break;
     }
     other.m_value.position = 0;
@@ -64,8 +62,7 @@ function::function(const function& other)
         new (&m_value.native) native_function(other.m_value.native);
     } break;
     case function_t::Import: {
-        m_value.imp.moduleName = other.m_value.imp.moduleName;
-        m_value.imp.function   = other.m_value.imp.function;
+        m_value.imp = other.m_value.imp;
     } break;
     }
 }
@@ -83,8 +80,7 @@ function& function::operator=(const function& other) {
         new (&m_value.native) native_function(other.m_value.native);
     } break;
     case function_t::Import: {
-        m_value.imp.moduleName = other.m_value.imp.moduleName;
-        m_value.imp.function   = other.m_value.imp.function;
+        m_value.imp = other.m_value.imp;
     } break;
     }
 

furvm/src/main.cpp

@@ -30,7 +30,7 @@ int main(void) {
     furvm::function_h mainFunc   = mainModule->emplace_function("main", 0);
 
     furvm::executor_h executor = context->emplace_executor(context);
-    executor->push_frame(mainModule, mainFunc);
+    executor->push_frame(mainModule, *mainFunc);
 
     static constexpr std::size_t FPC = 3; // Frames per collection