TangentCode

Overview

To work through Learntris and other coding challenges here, you'll write a program on your local computer in the language of your choice. The only requirement is that your program write to standard output and read lines either from standard input or a text file.

To test your program, you need to install tanco. Tanco is a command-line program that runs your program and sends it inputs from our server. Tanco reports the output of your program to the server for scoring.

Once you pass a test, it will download a rule to check that test locally.

Getting Set up

Tanco is a command line program written in python. You will need to install python, then install the tanco package, and then use tanco to connect to the server.

1. First Install Python 3.11 or newer. tanco. Tanco is written in python, so you need to install python first.

2. Python should come with a program called pip that lets you install packages. It might be called pip3.11 or pip3 on your machine, especially if you have other versions of python installed. If for some reason you don't have it, run python -m ensurepip to install it.

3. Install tanco with the command: pip install tanco

4. If you already had tanco installed (because you worked through the above steps in the past) you can run : pip install --upgrade tanco to make sure you have the latest version.

5. Ensure that you can run the tanco command. It should show you a list of available sub-commands, like so:

   tanco command line client
   
   usage: tanco [command]
   
   available commands:
   
     challenges      :  List challenges
     check           :  Check that the target program runs
     delete          :  Delete a challenge
     import          :  Import a challenge
     init            :  Create .tanco file in current directory
     login           :  Login to the server
     next            :  Fetch the next test
     show            :  Show the current test prompt
     test            :  Run the tests
     whoami          :  Show the current user
     shell           :  Run an interactive shell
   

6. Run tanco login to log into the server through your web browser. For this alpha testing phase, you will need a Google account to log in. Also, logging in with Firefox login is not yet working. (The login page currently requires third-party cookies, which Firefox blocks by default.)
7. Create a working directory for your program. It's not absolutely required, but it's a good idea to set up version control in the directory, perhaps with git init.

8. Run tanco init in the working directory to create a .tanco file. This file will store your login credentials and other information about the challenge.

   tanco will list the available challenges and prompt you to enter a challenge name. Enter learntris-classic.

9. Write a program that does nothing, using your language of choice.
10. Edit the .tanco file to tell it how to run your program.
11. Run tanco check to test your configuration until the program runs.
12. Once tanco check can run your program, you're ready to go.

Working through the challenge.

Once you have launched a challenge attempt, you can view the test prompts either in your terminal or through the actually-RESTful API at https://tanco.tangentcode.com/.

From the API, click "my data" and then the link for the attempt. This will take you to a page that is connected to the server with a websocket and will show live updates as you run the tests on your local machine.

From your terminal, the main workflow looks like this:

  # already done:
  # run `tanco login` # to log in with google account.
  # run `tanco init`  # to select challenge ande create a .tanco file
  make a do-nothing program
  while `tanco check` is not passing:
      tweak `.tanco` file
  you now start with 0 tests, so...
  run `tanco next` to get the first test
  while challenge is not complete:
      if `tanco test` fails:
          edit program to pass the failing tests
      else:
          commit any changes
          refactor or optimize your code (if you like)
          if you're ready to continue:
              run `tanco next` to get the next test