Re:Excel as Code
by WorldMaker on Monday September 20, 2021 @01:09PM
(#28596086)
VBA was not recent. Also, you'd be amazed by Turing Complete things like what someone determined can do with just VLOOKUP(). That's even before you get into truly abstract models of things proven Turing Complete such as Rule 110 of Cellular Automata and how easy/hard you can implement them in Excel without VBA Macros or "advanced functions".
Re:Excel as Code
by thefifthsetpin on Monday September 20, 2021 @03:23PM
(#28597717)
Can't you just implement a turing machine in Excel by using the cells in a row as your tape?
* Store the initial internal state in A1.
* Store the initial head position B1.
* Store the initial state as boolean values in the rest of row 1.
* Write simple lookup formulas in row 2 to compute the next state from the previous row.
* Fill down. Look for the halting state in column A and your output will be written in that row.
What am I missing?
Yeah you can, I made one here a long time ago: https://www.felienne.com/archives/2974 :)
Because Excel was not Turing complete until recently.