Pretty difficult and complex kata for being ranked a 6th kyu, very well thought.

might be interested:
http://butunclebob.com/ArticleS.UncleBob.TheBowlingGameKata

Because of the sorted bit, a == c means a == b == c, so the equilateral condition can be a == c and the isosceles condition can be a == b or b == c.

TL;DR, it all depends on who you are writing the code for. Personally, I enjoyed it but wouldn't write it.

This feels like an age old argument between concise and readable code. To a complete beginner this would not be very useful or accessible. For me, knowing some JS and a week into learning Python, it is not readable but fun and interesting to dissect and understand, and it helps me to learn. Thank you. And I can easily understand that this becomes quite obvious with time.

Can you explain, please? I wrote the same code..
i'm a beginer and i don't understand why this code is horrible...

The point was to hand-write a recursive function :)

The point of solving the issue was making it as short as possible.
Therefore, using the arrow function and removing the brakets were neccary.

It's clever, but not best practice at all :)

Das wäre in der Tat auch eine Lösung gewesen,
aber ich wollte ja eine möglichst kurze Lösung haben. :P

Davon abgesehen, sollte man die Funktion nicht auf meine Art implementieren, und auch möglichst auch ein reverse mit anschließender for-Schleife ;D

HORRIBLE CODE

Nice kata. Correctly graded at 7 kyu.

Print the input to help you debug your code. It is not case insensitive.

As an example, the word "hello" would become "0.1.2.2.3". For this task case-sensitivity is ignored, so "hello", "helLo" and "heLlo" will all return the same word pattern.

I have problem in execute to exercise, expected '0.1.2.3.4' to equal '0.1.2.2.3'. Same in my machine return be corret

In this case he had to remove the given brackets so this actually took longer, but very clever!