Brainfucc

A small brainfuck interpreter for nodejs.

Introduction

Brainfuck is the most famous esoteric programming language, it's syntax consists of only 8 commands, represented by the following characters > < + - . , [ ].

| Command | Description | | - | -----------------| | > | Moves pointer to the right. | | < | Moves pointer to the left. | | + | Adds 1 to the memory cell under the pointer. | | - | Subtracts 1 from the memory cell under the pointer. | | . | Outputs the ASCII character represented by the value present in memory cell under the pointer. (Ex: 48 => 0) | | , | Input a character and stores it's value in the memory cell under the pointer. | | [ | Jump past the matching ] if the cell under the pointer is 0. | | > | Jump back to the matching [ if the cell under the pointer is nonzero.|

Installation

$ npm install brainfucc

Basic usage

const brainfucc = require('brainfucc')

// Call brainfucc function.
brainfucc('+[-[<<[+[--->]-[<<<]]]>>>-]>-.---.>..>.<<<<-.<+.>>>>>.>.<<.<-.')

The above code will output hello world in the console.

Features

Memory Structure

• Brainfucc implements the memory as an array of 8-bit integers raging from 0 to 255.

• This memory wraps, so if you decrement a 0 it becomes a 255 and if you increment a 255 it becomes a 0.

• Memory by default has 30000 cells, initialized as 0.

Options

• memory - Controls the number of memory cells available to the code (Default = 30000).

// Makes available 5 memory cells. The code bellow outputs '0'.
brainfucc('++++++[> ++++++++ < -] > .', { memory: 5 })

// Initializes
//  v
// [0,0,0,0,0]

• delay - Controls the delay between the execution of each command, in milliseconds (Default = 0).

// Forces a 10 millisecond delay between each command execution.
brainfucc('+[-[<<[+[--->]-[<<<]]]>>>-]>-.---.>..>.<<<<-.<+.>>>>>.>.<<.<-.', { delay: 10 })

• debug - Display before each command, the current code position, loop stack and memory condition (Default = false). OBS: Memory condition is only displayed if the memory parameter is set to a value smaller than 51.

// Displays information about the current state of the machine at each step.
// The code bellow outputs '0'.
brainfucc('++++++[> ++++++++ < -] > .', { debug: true, memory: 5, delay: 200 })

Comments and whitespaces

• Brainfucc ignores every character except for the 8 brainfuck symbols > < + - . , [ ]. So comments can be made with any other characters.

// The code bellow will still output 'hello world'.
brainfucc('+[-[<<[+[--->]-[<<<]]]>>>-]>-.---.>..>.<<<<-.<+.>>>>>.>.<<.<-. returns a hello world!')

// Brainfucc also ignores spaces and newlines so
// the code bellow will still output 'hello world'.
brainfucc(`+[-[<<[+[--->]-
[<<<]]]>>>-]>-.---.>..>.<<<<-.
<+.>>>>>.>.<<.<-. 
returns a hello world!`)

Code validation and Runtime errors

• Brainfucc checks the code before running for mismatched loop brackets. If any dangling brackets are encountered it throws an exception.

// The code bellow will throw an exception.
brainfucc('[[]')

• If the code tries to access unavailable memory, Brainfucc throws an exception.

// The code bellow will throw an exception for 
// trying to access memory at the -1 position.
brainfucc('<')


// The code bellow will throw an exception for trying to 
// access memory greater than the number of cells alocated.
brainfucc('>>>', { memory: 3 })

Contributing

If you find a bug or think that something is hard to understand feel free to open an issue or contact me on twitter @cvmcosta, pull requests are also welcome :).

License