Brainfuck is an esoteric programming language created in 1993 by Urban Müller. Notable for its extreme minimalism, the language consists of only eight simple commands, a data pointer and an instruction pointer. While it is fully Turing complete, it is not intended for practical use, but to challenge and amuse programmers.
One of the first hackathons I ever took part in requires us to code a Brainfuck interpreter in less than 1h. While my team failed, I felt we did come up with a good solution to it. Rather than dealing with the problem via a series of if statements, given the predictable nature of Brainfuck we decided to use a dictionary that maps the various commands to a series of functions.
The language itself consists of only eight commands, listed below. A brainfuck program is a sequence of these characters, sometimes interspersed with other characters uses as comments (these are ignored when running the program). The commands are executed sequanttially. The language uses a simple machine model consisting of the program instruction pointer as well as a one-dimensional array of 30000B all of which init to 0, a data pointer which ints to the left-most bite, and two streams of bytes for input and output (the output being in ASCII).
The eight commands consist of a single character
| Char | Meaning |
|---|---|
> |
Increment the data pointer |
< |
Decrement the data pointer |
+ |
Increment the byte at the data pointer |
- |
Decrement the byte at the data pointer |
. |
Output the byte at the data pointer |
, |
Accepts one byte of input, storing its value at the data pointer |
[ |
If the byte at the data pointer is zero, skip ahead to the byte after the corresponding ] |
] |
If the byte at the data pointer is non-zero, skip back to the byte after the corresponding [ |
brainfuck HelloWorld.bf