To get familiar with Rust as a programming language, I decided to write an interpreter for the programming language Brainfuck.
Even though the name of this programming language sounds intimidating, it is reasonably easy to understand. In its essence Brainfuck simulates a Turing machine with 30000 byte cells, a data pointer pointing a the current cell, and a command pointer pointing at the current command to be executed. Using eight different commands, the value of those can be manipulated and printed. Different characters represent those eight commands:
| Â Character | Â Command |
|---|---|
> |
Increment the data pointer (move right to the next cell). |
< |
Decrement the data pointer (move left to the previous cell). |
+ |
Increment current cell value by one. |
- |
Decrement current cell value by one. |
. |
Output cell value at which data pointer currently points to. |
, |
Read an input and store it in the cell the data pointer currently points to. |
[ |
If the current cell is zero move the command pointer forward to the matching ] . |
] |
If the current cell is non-zero move the command pointer backward to the matching [ |
Before running a Brainfuck program all cells are set to 0 and the data pointer points that the first cell.
++[-]+>
The Brainfuck program shown above first increments cell 0 to 2 ++. Then decrements cell 0 until it is 0 again [-]. Then increments cell 0 by one + and moves the data pointer > to the right to point to cell 1.
Run hello world example with cargo:
cargo run -- tests/hello_world.bfBuild executable and run:
cargo build --release --all-features
cd target/release
/brainfuck_rust ../../tests/hello_world.bf