Wednesday, February 22, 2012

pybfc, A BF to C Compiler written in Python

So instead of studying for my exams, I decided to be less than productive and wrote a simple brainfuck to C compiler, in Python. I didn't initially mean for this to come out as hacky as it did, but I eventually decided I wanted to buff it down to 10 lines maximum.

Compiling brainfuck to C is pretty simple really, since all instructions in bf can be seen as operations on a single pointer variable in C, so all that needs to be done is replace each character with the appropriate C statement, which I did through a dictionary. There's a bit of code needed to initialize the program, but from then on it's all just one-to-one replacing. Finally, the script calls gcc to compile the code to be executable, using an optional command line argument as the output filename.

To compile bf code, save this as (for example) pybfc, and then run:
./pybfc .bf outputfilename
You can then execute the generated program just by running ./outputfilename.

Here's the source for a "Hello World!" program in brainfuck:
This compiles to some rather lengthy C code, I won't post it here, but the compiler will actually generate the C code into a file ("out.c") as well.

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