An interpreter for brainfuck, written in whitespace.

More specifically, the interpreter is written in an ASM-like language that compiles 1-to-1 into a Whitespace program. You can find the original source code in bf.wsasm. Compilation is handled by whitespace-rs, so if you have it installed, you can compile it as follows:

$ wsc -t -m -f asm bf.wsasm >bf.ws

The resulting program can be executed using the same tool:

$ wsc --unchecked-heap bf.ws

The program is read from STDIN until a ! character is encountered, after which all bytes will be considered input to the program.

$ echo '+++[->,+.<],.!foo' | wsc --unchecked-heap bf.ws
gpp

The version of BF simulated by this interpreter has an unbounded number of 8-bit cells to the right. Moving left of the starting cell doesn't work.