BitRL Example 2 Using GymWalk Environment

The bitrl::envs::gdrl::GymWalk is an implementation of the environment from https://github.com/mimoralea/gym-walk. Just like with BitRL Example 1 Using Gymnasium environments (Part 1), you will need an instance of the bitrl-envs-api server running in order to actually use the environment. Other than that there isn't much to say for this example. Below is the driver code.

#include "bitrl/bitrl_types.h"
#include "bitrl/envs/gdrl/gym_walk.h"
#include "bitrl/network/rest_rl_env_client.h"
 
#include <any>
#include <iostream>
#include <string>
#include <unordered_map>
 
namespace example_1
{
using namespace bitrl;
 
const std::string SERVER_URL = "http://0.0.0.0:8001/api";
 
using bitrl::envs::gdrl::GymWalk;
using bitrl::network::RESTRLEnvClient;
 
void test_gymwalk(RESTRLEnvClient &server)
{
// the environment is not registered with the server
std::cout << "Is environment registered: " << server.is_env_registered(GymWalk<4>::name)
<< std::endl;
 
    // when the environment is created we register it with the REST client
    GymWalk<4> env(server);
 
    // environment name can also be accessed via env.env_name()
    std::cout << "Is environment registered: " << server.is_env_registered(env.env_name())
              << std::endl;
    std::cout << "Environment URL: " << env.get_url() << std::endl;
 
    // make the environment we pass both make options
    // and reset options
    std::unordered_map<std::string, std::any> make_ops;
    std::unordered_map<std::string, std::any> reset_ops;
    reset_ops.insert({"seed", static_cast<uint_t>(42)});
    env.make("v1", make_ops, reset_ops);
 
    // query the environemnt version
    std::cout << "Environment version: " << env.version() << std::endl;
 
    // once the env is created we can get it's id
    std::cout << "Environment idx is: " << env.idx() << std::endl;
 
    // the created flag should be true
    std::cout << "Is environment created? " << env.is_created() << std::endl;
 
    // environment should be alive on the server
    std::cout << "Is environment alive? " << env.is_alive() << std::endl;
 
    // FrozenLake is a discrete state-action env so we can
    // query number of actions and states
    std::cout << "Number of valid actions? " << env.n_actions() << std::endl;
    std::cout << "Number of states? " << env.n_states() << std::endl;
 
    // reset the environment
    auto time_step = env.reset();
 
    std::cout << "Reward on reset: " << time_step.reward() << std::endl;
    std::cout << "Observation on reset: " << time_step.observation() << std::endl;
    std::cout << "Is terminal state: " << time_step.done() << std::endl;
 
    //...print the time_step
    std::cout << time_step << std::endl;
 
    // take an action in the environment
    // 2 = RIGHT
    auto new_time_step = env.step(1);
    std::cout << new_time_step << std::endl;
 
    // get the dynamics of the environment for the given state and action
    auto state = 0;
    auto action = 1;
    auto dynamics = env.p(state, action);
 
    std::cout << "Dynamics for state=" << state << " and action=" << action << std::endl;
    for (auto item : dynamics)
    {
        std::cout << std::get<0>(item) << std::endl;
        std::cout << std::get<1>(item) << std::endl;
        std::cout << std::get<2>(item) << std::endl;
        std::cout << std::get<3>(item) << std::endl;
    }
 
    // discrete action environments can sample
    // actions
    action = env.sample_action();
    std::cout << "Action sampled: " << action << std::endl;
 
    new_time_step = env.step(action);
    std::cout << new_time_step << std::endl;
 
    // close the environment
    env.close();
}
 
} // namespace example_1
 
int main()
{
 
    using namespace example_1;
 
    RESTRLEnvClient server(SERVER_URL, false);
 
    std::cout << "Testing GymWalk..." << std::endl;
    example_1::test_gymwalk(server);
    std::cout << "====================" << std::endl;
    return 0;
}