brainfuck

Everything related to the Brainfuck language

Table of content

• What is brainfuck
  • Interpreter Design
  • Instructions
• Features
• Usage
• Issues
• Initial Goal for the interpreter in C
• Goals
• Web Interpreter
• References

What is Brainfuck?

Brainfuck is a esoteric language that is turing complete so theoretically anything that a turing machine can compute can be computed in brainfuck. It's distinguishing feature ks that it only uses eight symbols for instructions (and ignores rest) to do anything achievable (given infinite time and memory).

Interpreter design

• the size of the tape is taken 30000 in general
• the program terminates if tape cell -1 or 30001 is tried to access
• each cell is 1 byte in size storing from 0 to 255
• incrementing 255 gives 0
• decrementing 0 gives 255 (making a full circle)

Instructions

• + - increment the value of current cell by 1
• - - decrement the value of current cell by 1
• > - shifts the memory pointer to right by one
• < - shifts the memory pointer to left by one
• [ - jump to the next corresponding ] if value at current cell is zero
• ] - jump to the next corresponding [ if value at current cell is non zero
• . - output the value of current cell in ASCII
• , - take one byte input from user and store as integer

Features

• execute a file via

brainfuck <file>

• enter interactive mode (REPL) via

brainfuck

• gives helpful errors
  • Error: Couldn't open file: <file>
  • Error: Maximum tape length exceeded
  • Error: Tried to access negative tape cell
  • Error: Couldn't find corresponding [
  • Error: Couldn't find corresponding ]
• access the binaries in the release section

Usage

• Execute from a file

brainfuck <file>

• Interactive shell (REPL mode)

brainfuck

• Help menu

brainfuck -h
#or
brainfuck --help

• Version number

brainfuck -v
#or
brainfuck --version

• About author

brainfuck --about

• Anything else shows the usage menu

Issues

• currently user can't input newline \n intentionally at both , command and REPL
• command length is hardcoded at 50KB
• REPL prompt gets cut off at space character due to %s scanf behaviour of C
• loops spanning multiple REPL prompts isn't possible (probably won't implement)

Goals

• Brainfuck interpreter in C ✅
• Brainfuck interpreter for the web in JavaScript ⏳
• Brainfuck example programs (Either code myself or make a program to do that)
  • Add / subtract
  • other algorithms like sum/factorial (Not even sure how would I approach that)
• Brainfuck compiler in C
• Brainfuck interpreter in Brainfuck
• Brainfuck explainer/debugger
• Brainfuck targeting transpiler
• Brainfuck compiler in Assembly (The last chad move) 😂😂
• Brainfuck in logic gates 💥

Web Interpreter

The Plan

• a functioning terminal
  • proper character input (mobile support)
  • backspace, other better keyboard support
• the actual interpreter
• binding the terminal and interpreter

References

• brainfuck.org
• Tutorial and Interpreter (No cheating at first)
• Esolangs