Brainfuck to JavaScript compiler

Overview

Brainfuck compiler that executes Brainfuck code in Java and transpiles it to JavaScript.

The following phases of the compiler are supported:

1. Lexical Analysis (Tokenization). The text of the program is broken up into Tokens and kept inside of a computer’s memory;
2. Parsing. A sequence of Tokens is being analyzed, and a parse model consisting of Statements and Expressions is constructed showing syntactic relation between commands;
3. Code Optimization. Subsequent increment, decrement, and shift commands are replaced by a single aggregate operation;
4. Code Generation or Execution:
   • Code Generation. Brainfuck program is transpiled into JavaScript code;
   • Code Execution. Brainfuck program is being interpreted in Java.

Quickstart

Use BrainfuckCompiler command-line utility to try out how the transpiler works.

To execute a classic "Hello World!", create a file with Brainfuck code:

echo "++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++." > /tmp/HelloWorld.b

Then, run the compiler with ./gradlew run passing arguments for input Brainfuck and output JS files.

./gradlew run --args="-i /tmp/HelloWorld.b -o /tmp/HelloWorld.js"

First, BrainfuckCompiler executes Brainfuck code in Java, then transpiles it to JavaScript, and evaluates generated script inside the Nashorn JS engine.