fes2bf

Brainfuck interpreter/compiler/transpiler using Fantom programming language.

It contains an interpreter with different optimizations and a transpiler to Fantom code.

This little project is an exploration of Object Oriented Programming and ideas from the blog of Yegor Bugayenko. It emphasizes the use of immutable classes, small classes and no static methods.

Installation

1. Install fantom following the instructions.

2. Clone this repository and build the program or download the pod and execute it.

Build the program

Once Fantom is installed and the repository is cloned, enter in the project directory and execute:

fan build.fan

this should build a fes2bf.pod and put it in the lib directory of Fantom's distribution.

Install from the pod repository

If Fantom is installed you just only need to download the package from the Fantom Pod Repository. Go to Eggbox/fes2bf and follow the instructions.

Usage

fan fes2bf <brainfuck-program>

Examples

In folder res there are some brainfuck programs. I'm sorry I don't remember the source of all of them.

There are more examples in http://esoteric.sange.fi/brainfuck/bf-source/prog/.

For instance:

fan fes2bf -c res/mandelbrot.b

Options

The program has the following options:

• -help, -h Print usage help
• -debug -d Show debug information
• -optimize, O <Int> Optimization level (see Optimizations below)
• -compile, -c Compiles to a fan script and execute it

Optimizations

You can measure the time between a program and the optimized version.

fan fes2bf --optimize <n>

or

fan fes2bf -O <n>

where n can be

• 0 No optimizations
• 1 Remove comments
• 2 Group instructions (and previous)
• 3 Replace [-] with Zero instruction (and previous).
• 4 Precalculate jumps (and previous)

By default optimizations are set to maximum level.

Anecdotal benchmark

A simple benchmark in a Intel(R) Core(TM) i5-7400 CPU @ 3.00GHz taken from the trash, shows the effect of the different optimizations.

Optimization	bench.b	Transpiled
(0) No optimization	21.445s	6.554s
(1) Remove comments	20.886s	6.296s
(2) Group	14.260s	4.319s
(3) Zero	3.567s	1.784s
(4) Calculated Jumps	2.538s	1.753s

res/mandelbrot.b

Optimization	mandelbrot.b	Transpiled
(0) No optimization	5m17.643s	Error(*)
(1) Remove comments	5m10.597s	Error(*)
(2) Group	1m32.024s	9.881s
(3) Zero	1m28.525s	9.554s
(4) Calculated Jumps	35.152s	9.513s

(*) Issue #1