yrizos/brainfart

An over-engineered Brainfuck interpreter.

0.2.0 2019-06-01 23:50 UTC

Requires

• php: >=7.2
• symfony/console: ^4.3

Requires (Dev)

• phpstan/phpstan: ^0.11
• phpunit/phpunit: ^8.1
• symplify/easy-coding-standard: ^6.0

MIT

• Yannis Rizos

README

Brainfart is Brainfuck interpreter, in PHP.

Try it out:

./bin/brainfart ./tests/scripts/sort.bf "100 5 99 200" 

Syntax

Memory operations

• > Moves the memory pointer to the right.
• < Moves the memory pointer to the left.
• + Increments the byte at the memory pointer by one.
• - Decrements the byte at the memory pointer by one.

Input / Output operations

• . Outputs the byte at the memory pointer.
• , Accepts one byte of input and stores it at the memory pointer.

Loops

[ If the byte at the memory pointer is zero, jump to the command after the matching ].

Named sequences

:<alpha><brainfuck>; will replace occurrences of <alpha> with <brainfuck>.

mf5mf5[>mf5++>mf5mf5>+++>+<<<<-]>++.>+.mf5++..+++.>++.<<mf5mf5mf5.>.+++.mb3mb3.mb3mb3--.>+.>.:mf5+++++;:mb3---; 

Will output: Hello World!\n (hopefully)

Interpreter instructions

!! separates input from commands. If present, whatever is left of it will be interpreted as comma separated input.

5,10,15,20!!>>,[>>,]<<[[-<+<]>[>[>>]<[.[-]<[[>>+<<-]<]>>]>]<<]

@@ will turn off peephole optimization. This may or may not weaken performance.

$$ will force a string output, instead of the default array.

Misc

• ~ Sleep for as many seconds as the value of the byte at the memory pointer. This will definitely weaken performance.

Design

Peephole optimization

Consecutive similar memory pointer commands will be grouped. +++++ will be interpreted as a single command that increments the byte at the memory pointer by five.

This may or may not improve performance.

Bugs

There are probably a ton of bugs. They are all intentional, to make coding in Brainfart a bit more challenging and fun. </lie>