brainiac_22ccb748d608358e

brainiac_22ccb748d608358e is an implementation of the Brainfuck esoteric computer language in Rust's macro_rules.

It is named brainiac_22ccb748d608358e to ensure that if there is a crate with a more apt need for the "brainiac" name, that this "fun" crate doesn't take its place.

Implementation

Brainfuck is a relatively simple language.

A program is initialized with a tape of 30,000 bytes, starting at index 0.

There are 8 commands available:

• >: Increment the index on the tape by 1
• <: Decrement the index on the tape by 1
• +: Increment the value at the current tape index by 1
• -: Decrement the value at the current tape index by 1
• .: Output the value at the current tape index to stdout
• ,: Assign the tape at the current index a u8 value off of stdin
• [: If the value at the current index of the tape is 0, move to the first command after a matching ']' character
• ]: Jump back to the matching '[' character

Limitations

There are several limitations due to how Rust interprets tokens in a macro:

• >> must be > >
• -> must be - >
• << must be < <
• <- must be < -
• .. must be . .

This ensures that there aren't any symbols in invalid locations.

Usage

Usage should be as easy as adding the package to your Cargo.toml manifest and importing the brainfuck macro:

use brainiac_22ccb748d608358e::brainfuck;

fn main() {
    brainfuck! { [This does absolutely nothing except make the compiler do extra work.] }
}

Special Thanks

To the Little Book of Rust Macros for being an easy way to get started with macros in Rust, and to Wikipedia's Brainfuck page, for explaining the rules of the language, and for the documented examples.