ANN static struct Env_Scope_ *new_envscope(MemPool p) {

  struct Env_Scope_ *a = mp_calloc(p, Env_Scope);

  vector_init(&a->breaks);

  vector_init(&a->conts);

  vector_init(&a->class_stack);

  vector_init(&a->nspc_stack);

  vector_init(&a->known_ctx);

  return a;

Env new_env(MemPool p) {

  const Env env = (Env)xmalloc(sizeof(struct Env_));

  env->global_nspc = new_nspc(p, "global_nspc");

  env->context = NULL;

  env->scope = new_envscope(p);

  env_reset(env);

  return env;

ANN void env_reset(const Env env) {

  vector_clear(&env->scope->breaks);

  vector_clear(&env->scope->conts);

  vector_clear(&env->scope->nspc_stack);

  vector_add(&env->scope->nspc_stack, (vtype)env->global_nspc);

  vector_clear(&env->scope->class_stack);

  vector_add(&env->scope->class_stack, (vtype)NULL);

  env->curr = env->global_nspc;

  env->class_def = NULL;

  env->func = NULL;

  env->scope->depth = 0;

}

ANN void release_ctx(struct Env_Scope_ *a, struct Gwion_ *gwion) {

  const m_uint size = vector_size(&a->known_ctx);

  for(m_uint i = size + 1; --i;)

    REM_REF((Context)vector_at(&a->known_ctx, i - 1), gwion);

}

ANN static void free_env_scope(struct Env_Scope_  *a, Gwion gwion) {

  release_ctx(a, gwion);

  vector_release(&a->known_ctx);

  vector_release(&a->nspc_stack);

  vector_release(&a->class_stack);

  vector_release(&a->breaks);

  vector_release(&a->conts);

  mp_free(gwion->mp, Env_Scope, a);

}

ANN void free_env(const Env a) {

  free_env_scope(a->scope, a->gwion);

  while(pop_global(a->gwion));

  xfree(a);

}

ANN2(1,3) m_uint env_push(const Env env, const Type type, const Nspc nspc) {

  const m_uint scope = env->scope->depth;

  vector_add(&env->scope->class_stack, (vtype)env->class_def);

  env->class_def = type;

  vector_add(&env->scope->nspc_stack, (vtype)env->curr);

  env->curr = nspc;

  env->scope->depth = 0;

  return scope;

ANN void env_pop(const Env env, const m_uint scope) {

  env->class_def = (Type)vector_pop(&env->scope->class_stack);

  env->curr = (Nspc)vector_pop(&env->scope->nspc_stack);

  env->scope->depth = scope;

}

ANN void env_add_type(const Env env, const Type type) {

  const Type v_type = type_copy(env->gwion->mp, env->gwion->type[et_class]);

  ADD_REF(v_type);

  v_type->e->d.base_type = type;

  SET_FLAG(type, builtin);

  const Symbol sym = insert_symbol(type->name);

  nspc_add_type_front(env->curr, sym, type);

  const Value v = new_value(env->gwion->mp, v_type, s_name(sym));

  SET_FLAG(v, valid | ae_flag_const | ae_flag_global | ae_flag_builtin);

  nspc_add_value(env->curr, insert_symbol(type->name), v);

  v->from->owner = type->e->owner = env->curr;

  v->from->owner_class = type->e->owner_class = env->class_def; // t owner_class ?

  type->xid = ++env->scope->type_xid;

}

ANN m_bool type_engine_check_prog(const Env env, const Ast ast) {

  const Context ctx = new_context(env->gwion->mp, ast, env->name);

  env_reset(env);

  load_context(ctx, env);

  const m_bool ret = traverse_ast(env, ast);

  if(ret > 0) //{

    nspc_commit(env->curr);

  if(ret > 0 || env->context->global)

    vector_add(&env->scope->known_ctx, (vtype)ctx);

    REM_REF(ctx, env->gwion);

  unload_context(ctx, env);

  return ret;