This is a computing machine controlled by a 2-dimensional input language. Here's an example (examples/multiply):
v This program multiplies numbers in the first and second register and stores the result in the third register
. This program cannot handle negative numbers. If one of the inputs is negative, the program enters an infinite loop.
.
. Now go through a loop until the first register is 0.
. In the loop:
. - decrement the first register
. - add the second register onto the third
.
. Test the first register here
. | Print the third register (the result) and exit
. | |
. v v
>.[.\............]]dx
. -
. >].>.\.]].>.\.[[.v
. . . . . .
. . . . . .
. . - . - .
. [ ] ] [ .
. . + . . .
. [ ] ] [ .
. . + . + .
. . . . . .
. ^.< ^.< .
. .
^....................<
Here's another example. This one prints and decrements the first register until it is zero:
d-\x>
>.^
There are 10 "tapes". The initial values for the registers on tape 0 are read from standard input (or set to zero if none are provided).
It's written in Python 3. Run machine.py with the argument /path/to/input/file to be amazed.
We can chain multiple programs together, for example:
echo "3 5" | ./machine.py examples/multiply | ./machine.py examples/loop