nptr / bfrust

a brainfuck interpreter written in Rust

bfrust

A simple, slightly optimizing, brainfuck interpreter written in Rust for learning purposes, because a "Hello World!" is not a realistic start. The interpreter provides 64000 cells, each 8-bit wide. It optimizes three things:

• Consecutive < or > are merged into a ptr += operand instruction.
• Consecutive + or - are merged into a cell[ptr] += operand instruction.
• Jump destinations of [ and ] are resolved in a preprocessing step.

It should run most programs you'll find. Here are some good tests and examples:

• https://github.com/rdebath/Brainfuck/tree/master/testing
• https://github.com/saulpw/brainfuck/tree/master/tests

Usage

In a terminal, call bfr <filepath>

$ ./bfr Mandelbrot-tiny.b 
AAAAAAAABBBBBBBBCCCCCCCCCCCCCCCCCCDDDDEFEEDDDCCCCCBBBBBBBBBBBBBBB
AAAAAAABBBBBBCCCCCCCCCCCCCCCCCDDDDDDEEFIKGGGDDDDDCCCCBBBBBBBBBBBB
AAAAAABBBBCCCCCCCCCCCCCCCCCDDDDDDDEEEFGHKPIGFEDDDDDCCCCCBBBBBBBBB
AAAAABBBCCCCCCCCCCCCCCCCCDDDDDDDEEEFGPVT  Q[HEEEEDDDCCCCCCBBBBBBB
AAAABBCCCCCCCCCCCCCCCCDDDDDDDEEFFFGGHK      HGFFEEEDDDCCCCCBBBBBB
AAABBCCCCCCCCCCCCCCCDDDDDEEEFGK MJJ NR    YS L HHGIJFDDCCCCCCBBBB
AAABCCCCCCCCCCCCCDDDEEEEEEFFFHI                    MGEDDCCCCCCBBB
AABCCCCCCCCCCCDDEEEEEEEEFFFGY Q                   MHGEEDCCCCCCCBB
AACCCCCCDDDDDEEFLHGGHMHGGGHIR                      QLHEDDCCCCCCCB
ABCCDDDDDDEEEEFGIKU    RLJJL                        IFEDDCCCCCCCB
ACDDDDDDEEEEEGGHOS        QR                        JFEDDDCCCCCCC
ADDDDDEFFFGGHKOPS                                   GEEDDDCCCCCCC
A                                                PJGFEEDDDCCCCCCC
ADDDDDEFFFGGHKOPS                                   GEEDDDCCCCCCC
ACDDDDDDEEEEEGGHOS        QR                        JFEDDDCCCCCCC
ABCCDDDDDDEEEEFGIKU    RLJJL                        IFEDDCCCCCCCB
AACCCCCCDDDDDEEFLHGGHMHGGGHIR                      QLHEDDCCCCCCCB
AABCCCCCCCCCCCDDEEEEEEEEFFFGY Q                   MHGEEDCCCCCCCBB
AAABCCCCCCCCCCCCCDDDEEEEEEFFFHI                    MGEDDCCCCCCBBB
AAABBCCCCCCCCCCCCCCCDDDDDEEEFGK MJJ NR    YS L HHGIJFDDCCCCCCBBBB
AAAABBCCCCCCCCCCCCCCCCDDDDDDDEEFFFGGHK      HGFFEEEDDDCCCCCBBBBBB
AAAAABBBCCCCCCCCCCCCCCCCCDDDDDDDEEEFGPVT  Q[HEEEEDDDCCCCCCBBBBBBB
AAAAAABBBBCCCCCCCCCCCCCCCCCDDDDDDDEEEFGHKPIGFEDDDDDCCCCCBBBBBBBBB
AAAAAAABBBBBBCCCCCCCCCCCCCCCCCDDDDDDEEFIKGGGDDDDDCCCCBBBBBBBBBBBB

Finished in 2033 ms

Building

Provided you have the Rust toolchain installed, call cargo build from the project root or rustc main.rs from the src directory.