fix(furvm): improve executor flags

furvm/include/furvm/executor.hpp

@@ -83,6 +83,14 @@ public:
      * @return The flags.
      */
     executor_flags flags() const { return m_flags; }
+
+    bool done() const { return (m_flags & executor_flags::Done) == executor_flags::Done; }
+
+    bool suspended() const { return (m_flags & executor_flags::Suspended) == executor_flags::Suspended; }
+
+    void unsuspend() { m_flags = m_flags & ~executor_flags::Suspended; }
+
+    void clear_flags() { m_flags = m_frames.empty() ? executor_flags::Done : furvm::executor_flags{ 0 }; }
 public:
     /**
      * @brief Pushes a new frame.
@@ -173,7 +181,7 @@ private:
 private:
     static bool compare_thing_types(const thing_type& lhs, const thing_type& rhs);
 private:
-    executor_flags m_flags{}; // NOLINT(bugprone-invalid-enum-default-initialization)
+    executor_flags m_flags = executor_flags::Done;
     context*       m_context;
 
     std::stack<frame>   m_frames;

furvm/src/executor.cpp

@@ -104,6 +104,12 @@ void executor::push_frame(const mod_h& mod, function function) {
     default: throw std::runtime_error("unexpected function type");
     }
     if (m_newFrameCb) m_newFrameCb(*this);
+
+    if (!m_frames.empty()) {
+        m_flags = m_flags & ~executor_flags::Done;
+    } else {
+        m_flags = m_flags | executor_flags::Done;
+    }
 }
 
 struct executor::frame executor::pop_frame() {
@@ -117,6 +123,13 @@ struct executor::frame executor::pop_frame() {
     }
     if (m_stack.size() != frame.stackBase) throw std::runtime_error("unexhausted stack");
     if (returnValue.has_value()) push_thing(std::move(returnValue.value()));
+
+    if (!m_frames.empty()) {
+        m_flags = m_flags & ~executor_flags::Done;
+    } else {
+        m_flags = m_flags | executor_flags::Done;
+    }
+
     return frame;
 }