This one was a lot of fun! There’s something particularly satisfying about a kata where the input and output have to “speak the same language,” and every detail of the transformation matters. I found myself thinking about the problem from both directions rather than treating encoding and decoding as two completely separate tasks, which made the whole thing much more interesting. It’s a great little exercise in precision, pattern recognition, and making sure your assumptions actually hold in both directions. Definitely one of those katas where getting the final result feels more rewarding than the size of the solution suggests. Really enjoyed this one — thank you for the challenge! 🙌

done

The frustrating fact is that it took about 6 hours to solve this task. ●︿●

Scala translation

Approved

python new test framework

changed assert to expect

C translation couples encoding and decoding in a single call to an external test function. This makes it unnecessary difficult to test each function separately.
The user functions are not even declared in the test code!

Rust translation

Approved

C translation (author gone)

Ruby 3.0 should be enabled, see this to learn how to do it

Please organize the structure of test fixture as following (although it has been mentioned in the attached link, I'm repeated here again)

describe "<This message should describe the categories of test groups inside this block>" do
  it "<A short message describing this test group>" do
    expect(...).to eq(...) #Assertions
    #Or Test.assert_equals(user_response, reference_response)
  end
end

Seems already approved

Java Translation kumited