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Redo
Redo is an esolang created by User:cleverxia and iss a try to prove Alarm Clock Radio Turing complete, and I chose the name because Rewind is taken.
Syntax
Redo operates on a tape which initially has only 1 cell. A cell can store multiple (albeit the amount of numbers are bounded, and the numbers themselves are also bounded) numbers.
Redo has the following commands:
| command | meaning |
|---|---|
# |
goto the first cell. |
~ |
extend the tape 1 cell at the end. |
{n}[...] |
while the number n at the current cell is not 0 do ... |
+{n} |
increment number n at the current cell. |
> |
move the pointer to the right, moving off the tape is UB |
Computational class
The language itself is Turing-complete as the reanslation from BF exists.
> ~+{2}>
< +{2}^(MAX-1) #{2}[>]
+ +{1}
- +{1}^(MAX-1)
[ {1}[
] ]
With MAX being the integers' bound.
This works using the following tape structure:
(x,1)(x,1)(x,1) ... (x,1)(x,0)(x,0)...(x,0)
^ data pointer
However if this language's subset > +{n}# ~# {n}[# ]# is TC then Alarm Clock Radio must be too as this translation exists:
> >^P
+{n}# >^n+>^(P-n)[>^P]>
~# [>^P]+}>^(P+1)
{n}[#...]# >^n[>^(P-n)[>^P]> ... >^n]>^(P-n)[>^P]>
where P is PADSIZE. n must be a positive integer and less tha PADSIZE