Coroutines are mostly working but they're kind of junk anyway. Feel free to tinker with this if you like.

.vimrc_proj

@@ -1 +1 @@
-set makeprg=meson\ compile\ -C\ .
+set makeprg=meson\ compile\ -j\ 4\ -C\ .

Makefile

@@ -3,7 +3,7 @@
 all: build test
 
 build:
-	meson compile -C builddir
+	meson compile -j 4 -C builddir
 
 test:
 	meson test -C builddir --suite turings_tarpit

builder.cpp

@@ -56,6 +56,8 @@ void Builder::run_build() {
   while(fgets(buffer, BUF_MAX, build_out) != nullptr) {
     string line(buffer);  // yeah, that's probably a problem
 
+    cerr << buffer;
+
     smatch err;
     bool match = regex_match(line, err, err_re);
 

corotest.cpp

@@ -0,0 +1,125 @@
+#include <concepts>
+#include <coroutine>
+#include <exception>
+#include <iostream>
+#include <vector>
+#include <assert.h>
+#include <chrono>
+
+using namespace std;
+using namespace std::chrono;
+
+template<typename T>
+struct Task {
+  struct promise_type;
+
+  using handle_type = std::coroutine_handle<promise_type>;
+
+  struct promise_type {
+    T value_;
+    std::exception_ptr exception_;
+
+    Task get_return_object() {
+      return Task(handle_type::from_promise(*this));
+    }
+
+    std::suspend_always initial_suspend() {
+      return {};
+    }
+
+    std::suspend_always final_suspend() noexcept {
+      return {};
+    }
+
+    void unhandled_exception() {
+      exception_ = std::current_exception();
+    }
+
+    template<std::convertible_to<T> From> // C++20 concept
+    void return_value(From &&from) {
+      value_ = std::forward<From>(from);
+    }
+
+    template<std::convertible_to<T> From> // C++20 concept
+    std::suspend_always yield_value(From &&from) {
+      value_ = std::forward<From>(from);
+      return {};
+    }
+
+    void return_void() {}
+  };
+
+  handle_type h_;
+
+  Task() {
+  }
+
+  Task(handle_type h) : h_(h) {
+  }
+
+  Task(const Task &t) : h_(t.h_) {
+  }
+
+  void destroy() {
+    h_.destroy();
+  }
+
+  T operator()() {
+    assert(!h_.done());
+    call();
+    return std::move(h_.promise().value_);
+  }
+
+  bool done() {
+    return h_.done();
+  }
+
+  private:
+
+  void call() {
+    h_();
+
+    if (h_.promise().exception_)
+      std::rethrow_exception(h_.promise().exception_);
+  }
+};
+
+#define pass() co_await std::suspend_always{}
+
+Task<unsigned> task_test()
+{
+  pass();
+
+  for (unsigned i = 0; i < 3; ++i)
+      co_yield i;
+
+  co_return 1000;
+}
+
+int main()
+{
+
+  const int task_count = 4;
+  vector<Task<unsigned>> tasks;
+
+  for(int i = 0; i < task_count; i++) {
+    auto t = task_test();
+    tasks.push_back(std::move(t));
+  }
+
+  int done_count = 0;
+  while(done_count < task_count) {
+    for(int i = 0; i < task_count; i++) {
+      Task<unsigned> &t = tasks[i];
+
+      if(t.done()) {
+        t.destroy();
+        done_count++;
+      } else {
+        auto res = t();
+        cout << "T# " << i << " result "
+         << res << endl;
+      }
+    }
+  }
+}

game_engine.cpp

@@ -19,7 +19,7 @@ int GameEngine::determine_damage(string &type) {
     return damage_types.at(type);
   } catch(std::out_of_range &err) {
     print(ERROR, "BAD DAMAGE TYPE {}\n", type);
-    return 1000;
+    return 0;
   }
 }
 

meson.build

@@ -15,9 +15,6 @@ libgit2package_dep = libgit2_proj.dependency('libgit2package')
 
 efsw_dep = dependency('efsw')
 fmt = dependency('fmt')
-ftxui_screen = dependency('ftxui-screen')
-ftxui_dom = dependency('ftxui-dom')
-ftxui_component = dependency('ftxui-component')
 catch2 = dependency('catch2-with-main')
 sfml = dependency('sfml')
 json = dependency('nlohmann_json')
@@ -25,7 +22,6 @@ imgui = dependency('imgui-sfml')
 
 dependencies = [
   fmt, libgit2package_dep, efsw_dep,
-  ftxui_screen, ftxui_dom, ftxui_component,
   sfml, imgui, json
 ]
 
@@ -36,18 +32,11 @@ executable('escape_turings_tarpit',
     'builder.cpp',
     'sfmlgui.cpp',
     'escape_turings_tarpit.cpp'],
-  win_subsystem: 'windows',
   dependencies: dependencies)
 
 executable('regtest', 'regtest.cpp',
   dependencies: [fmt])
 
-executable('ftxtest', 'ftxtest.cpp',
-  dependencies: dependencies)
-
-executable('ftx_thread_test', 'ftx_thread_test.cpp',
-  dependencies: dependencies)
-
 executable('audiotest', 'audiotest.cpp',
   dependencies: dependencies)
 
@@ -57,6 +46,10 @@ executable('jsontest', 'jsontest.cpp',
 executable('threadtest', 'threadtest.cpp',
   dependencies: dependencies)
 
+executable('corotest', 'corotest.cpp',
+  dependencies: dependencies,
+  cpp_args: '-fcoroutines')
+
 runtests = executable('runtests', [
   'game_engine.cpp',
   'tests/game_engine.cpp',

scripts/reset_build.ps1

@@ -7,7 +7,6 @@ mkdir builddir
 meson wrap install fmt
 meson wrap install sqlite3
 meson wrap install sqlitecpp
-meson wrap install ftxui
 meson wrap install catch2
 meson wrap install libpng
 meson wrap install vorbis

scripts/reset_build.sh

@@ -10,7 +10,6 @@ cp *.wrap subprojects
 meson wrap install fmt
 meson wrap install sqlite3
 meson wrap install sqlitecpp
-meson wrap install ftxui
 meson wrap install catch2
 meson wrap install libpng
 meson wrap install vorbis