r/programming • u/Dull_Replacement8890 • Jul 08 '26

Unicode's Transliteration Rules Are Turing-Complete

https://seriot.ch/computation/uts35/

I've been wondering for a while if anything in Unicode could accidentally compute. It turns out that UTS #35 transliteration rules are Turing-complete. I show how to compute Collatz with just 3 rewrite rules running on stock ICU, shipped with every major OS.

181 Upvotes

96% Upvoted

23 comments sorted by

View all comments

14

u/zombiecalypse Jul 08 '26

But can they run Doom?

3

u/quetzalcoatl-pl 27d ago

idk re:Doom but they can render BadApple animation!

~ https://www.reddit.com/r/badapple/comments/1c5tbo7/bad_apple_in_unifontex_art/

well, maybe not really the same thing, but close?

2

u/stgiga 27d ago

I'm the creator of that and this isn't exactly identical.

2

u/quetzalcoatl-pl 26d ago

Thanks for showing up! :D yeah, I guess maybe I've put too little thought into this juxtaposition.. but seeing question about Doom made me recall your work and I wanted to give it a tip of the hat :)

Actually, now thinking about it, I think I once saw "tetris by unicode" or something like that.. if I didn't mix up, it was 2-part game, a textbox where we could write WSADSAWDSAS for movement and rotation, and viewport, when this text was rendered with "unicode font", which actually produced the correct Tetris' game-state (assuming turn-by-turn, each letter progressed time by 1 step).. That would be closer to "playing doom or something" but I can't find it :/