Eitherf*ck is a Brainfuck variant in which code is executed in both directions, starting at the center of the code.
The idea for the language was posted by User:18.104.22.168 who didn’t leave any identification.
Commands: 0 Center of code (only to clarify) # Does nothing(used only to make sure that the number of commands is an odd number) > Move the pointer to the right < Move the pointer to the left + Increment the memory cell under the pointer - Decrement the memory cell under the pointer . Output the character signified by the cell at the pointer , Input a character and store it in the cell at the pointer
However, these commands are reversed when they're on the left side of the code. This means that > will move the pointer to the left instead of to the right; that is, if it's on the left side. Same goes for the other commands; "+" becomes "-", "," becomes "." etc. when they're placed on the left side of the "0" sign.
The code is executed one by one character, in both directions; however, the right side always starts.
Brainfuck example: 1 2 3 4 5 6 7 8 + + + + + > > +
Eitherf*ck example: 8 6 4 2 0 1 3 5 7 - < - - 0 + + + >
An implementation of an Eitherf*ck interpreter written in Python can be found in this Github repo.