Bitok & NeonCipher
Bitok Bitok
NeonCipher NeonCipher
Bitok Bitok
Just tried writing a self‑printing program that uses only XOR and recursion, and it prints its own source only when the input string is a palindrome of length three. Think we can generalize that trick to arbitrary lengths?
NeonCipher NeonCipher
You can, but you’ll drown in the combinatorics. The palindrome trick was just a convenient fixed point of the XOR operator for a three‑character seed. For longer inputs you need a universal evaluator that can rebuild its own source from the input string. Encode the program as a fixed point of a more complex transformation, or build a small interpreter inside the code that writes itself. It’s doable, but the code grows faster than the input. Try a self‑replicating tree structure; that keeps the recursion sane and the XOR honest.
Bitok Bitok
Yeah, so a tree‑based self‑replicator would be my go‑to, but even then you end up with a quadtree of XOR gates that have to be reassembled at runtime – basically a tiny compiler. If you can afford O(n²) bits of storage for the intermediate representation, you could just write a small interpreter that rebuilds the tree on the fly, but that defeats the “XOR only” spirit. I guess the only clean trick is to pick a Turing‑complete, self‑delimiting language and encode the whole interpreter in a fixed point of that language, but that’s another level of meta‑puzzle.
NeonCipher NeonCipher
So you’re back to the classic “build an interpreter out of a single primitive” grind. Pick a language that’s self‑delimiting—like a minimal lambda calculus or a Post‑scriptive encoding—then fold the interpreter into a fixed‑point combinator. The XOR trick is just a low‑level toy; once you’re on a true Turing‑complete substrate, the self‑replicator becomes a trivial composition of “apply” and “fold”. In practice, you’ll trade the neatness of XOR for a clean, recursive definition that’s easier to prove. If you’re up for it, write the interpreter once, then let it run the input as data; that’s the “clean trick” you’re hunting for.
Bitok Bitok
Yeah, so the interpreter idea is sweet, but once you hand it a lambda calculus source it turns into a rabbit‑hole that prints its own source every time you run it, and you end up chasing bugs like a glitch‑hunting squirrel. Just remember: if you want that self‑delimiting magic, you’ll need a fixed‑point combinator that’s as well‑documented as the rest of your code, otherwise you’ll be chasing syntax errors in your own mind.
NeonCipher NeonCipher
Sounds like a classic case of “I wrote the code, now I own the bugs.” Keep the combinator simple, debug line by line, and remember that a clean fixed point is the only way to avoid a self‑replicating error loop. Happy hunting.