DP console is TURING COMPLETE!

[divVerent]

(DISCLAIMER: if you do not know what a Turing machine is, do not read on)

I just found out that the DarkPlaces console is Turing complete...

get this config file http://mensa.ath.cx/~polzer/temp/math.cfg and type "exec math.cfg" in game. It will calculate the prime numbers from 2 to 79 and print them out as unary numbers... as strings of ones. You can easily make it print more primes by changing the number of "inc v0"s in the big block - or let it run infinitely by removing the inc v0 block altogether (which would only work on a dedicated server because the display won't update while the calculation is running).

The first lines of the file prove that the DP console is Turing complete, that is, that you can do ANY sort of calculation using aliases (simply because it is a known fact that the INC/CLR/JE register machine can). What you can do is just limited by memory... and creepiness of code

Have fun!

BTW: you can also use that file as CPU benchmark. Run the dedicated server like this:

Code: Select all

$ time nexuiz-dedicated +"exec math.cfg; quit"

It takes 6.21s CPU time on my computer.

EDIT: excuse the slight obfuscation

[GreEn`mArine]

you're creepy, sorry... (yes, I do know what a turing machine is, learned it today in theoretical info II xD)

[Psychcf]

well, I can see it's use, but it's nothing to jump out of your pants about. Unless it was a REALLY HOT GIRL, which it's not...

interesting idea, you could use it for things like gradual mouse sensitivity ajustment bindings, or certain ajustments based on cvar values. I think...

[divVerent]

Actually, it is hard to impossible to READ a value of a cvar, but one can (with quite some work, however) convert from unary to decimal representation...

so gradually changing sensitivity WOULD be possible. But even more ugly code...

This example proves that you can do basically everything in the DP console - but it does not prove that the resulting cfg files are maintainable.

[GreEn`mArine]

hehe, so it's time for you to write a neat parser

[Xeno]