Crate bf[−][src]

bf-rs is a optimizing Brainfuck interpreter and JIT compiler inspired by Eli Bendersky’s series on JIT compilation. It includes a library crate bf that exports most of the functionality, and an executable bfi that provides a command-line interface for executing Brainfuck programs.

This crate supports Rust version 1.20 and later. However, by default, installing bf does not enable the JIT compiler because that requires nightly Rust. To build and install from crates.io with the native x86-64 JIT enabled:

$ cargo +nightly install bf --features=jit

This library implements a number of compilation passes:

First, Brainfuck concrete syntax is parsed into an abstract syntax tree.
Then, repeated sequences of the same command are run-length encoded.
Then, common loop forms are converted to new (non-Brainfuck) instructions by the peephole optimizer.
The peephole output can be flattened to bytecode, which is then interpreted.
Or, if the jit feature is enabled (nightly only), the peephole output can be just-in-time compiled to x64 machine code.
Or, if the llvm feature is enabled (LLVM ≥ 3.8 must be in the PATH to build), the peephole output can be JIT compiled using LLVM. (This is quite slow right now.)

Interpreters are provided for the intermediate forms as well. In particular, all representations of Brainfuck programs implement the Interpretable trait.

Modules

ast	Parsing and interpretation for unoptimized Brainfuck abstract syntax trees.
bytecode	Brainfuck bytecode instead of an abstract syntax tree.
common	Definitions common to multiple passes.
jit	Just-in-time compiles Brainfuck AST to x64 machine code (`--features jit`, nightly only)
llvm	JIT compiler for Brainfuck based on LLVM.
peephole	The peephole optimizer, which replaces common loop forms with single (non-Brainfuck) instructions.
rle	Run-length encodes Brainfuck commands.
rts	Minimal run-time system, which does I/O.
state	The Brainfuck machine state.
test_helpers	Helper definitions for testing both inside and outside (e.g., benches) the crate.
traits	Contains the Interpretable trait, which provides a common interface for running a Brainfuck program.