Malfunge

Malfunge is an esoteric programming language created by User:ArthroStar11 heavily inspired by Befunge and Malbolge

Data Structure

The data structure of Malfunge is an array of 5 stacks of 32-bit signed integers each with a max size of 1000

Playfield

Much like Befunge, Malfunge uses a playfield of fixed size. In the case of Malfunge the playfield is a 256 x 256 table of characters.

Command List

Flow Control

Important note: for brevity this section will mention "h-cond" and "v-cond" these represent behaviors identical to Befunge's _ and | respectively

• Retroreflectors (<, >, ^, and v)
  • if approaching from the concave side (i.e from the left with ">) will invert the direction of the program (i.e. left for >)
  • if approaching from the sloped sides (i.e from above or below with >) will send the program in the direction of the point (identical to Befunge)
  • if approaching from the pointed side (i.e from the right with >) will perform a v-cond if retroreflector is pointing horizontally, h-cond otherwise
• Paddles (| and _)
  • | will invert the direction if approaching from the left or right, performs an h-cond otherwise
  • _ will invert the direction if approaching from above or below, performs a v-cond otherwise
• Mirrors (/ and \)
  • will reflect the direction 90 degrees represented visually by the mirror (behaves identically to AsciiDots)
• Misc
  • ? changes the direction randomly
  • o skips the next command in the direction of the pointer

Math

• numbers (0 to 9)
  • pushes the corresponding number to the current stack
• Operators (P, M, T, D, and m)
  • pops a then b off of the current stack then pushes b(op)a onto <(current stack + 1) % 5>
    • P adds
    • M subtracts
    • T multiplies
    • D divides
    • m performs modulo

Stack Control

• S shifts to the next stack up
• s shifts to the next stack down

I/0

on current stack

• user input
  • , pushes user input as a character
  • . pushes user input as an integer
• output
  • ; pops value as a character and prints
  • : pops value as an integer and prints

Misc

• " toggles string mode (identical to Befunge)
• I pops a then b off the current stack then pushes 1 if b>a, pushes 0 otherwise
• i pops a off the current stack then pushes 1 if a == 0, pushes 0 otherwise
• d duplicates top value
• @ ends the program

Sample Programs

Hello World

0"!dlrow olleh"o>d;v
                >  <
                @

Truth Machine

.o>dd:v
  >   <
  @

Cat Program

An infinitely repeating cat program is implemented in the following:

o>,;v
 ^  <

Implementation

ArthroStar11's Interpreter (C source) (dead link)

Common Lisp implementation of the Malfunge programming language.