rsiemens / brainfuck

A brainfuck interpreter written in python

Brainfuck is an esoteric programming language created in 1993 by Urban Müller, and notable for its extreme minimalism.1

The language consists of eight simple commands, which make it a nice language to implement when learning about compilers and interpreters. Which is exactly what this is.

Basic usage looks like...

python -m brainfuck -n examples/fibo.bf
>> 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89

Note: the example programs here can be found in the examples directory

stdin and stdout are the default i/o streams so you can do something like this.

python -m brainfuck examples/echo.bf < macbeth.txt >> shakespeare.txt

You can also import it as a python module.

>>> from io import StringIO
>>> import brainfuck
>>>
>>> out_stream = StringIO()
>>> with open('examples/hello.bf') as f:
...     brainfuck.eval(f.read(), output_stream=out_stream, optimize=True)
...
<State pointer:6 value:10>
>>> out_stream.getvalue()
'Hello World!\n'

You can use the optimize flag -o (or brainfunk.eval(..., optimize=True)) to perform some parsing optimizations. Since it adds additional parsing time only more complex programs will benefit from it.

Currently the following optimizations are performed with the -o flag:

• Token compressions - Repeat tokens are compacted into one command +++ becomes +3
• Reset loops - [-] and [+] which decrements/increment a memory value to 0 will simply set them to 0

Depending on your program this can significantly reduce runtime. Consider hanoi.bf which without optimization takes about 30min to run. With optimizations on it runs in about 2min.

Running the unit tests can be done from the project directory.

python -m unittest discover

brainfuck's Issues

Test Issue