fungus is a Befunge-93 interpreter written in go. Befunge is a two-dimensional stack-based, reflective, esoteric programming language.
| Instruction | Description |
|---|---|
| 0-9 | Push this number onto the stack. |
| + | Addition: Pop a and b, then push a+b |
| - | Subtraction: Pop a and b, then push b-a |
| * | Multiplication: Pop a and b, then push a*b |
| / | Integer division: Pop a and b, then push b/a, rounded towards 0. |
| % | Modulo: Pop a and b, then push the remainder of the integer division of b/a. |
| ! | Logical NOT: Pop a value. If the value is zero, push 1; otherwise, push zero. |
| ` | Greater than: Pop a and b, then push 1 if b>a, otherwise zero. |
| > | Start moving right |
| < | Start moving left |
| ^ | Start moving up |
| v | Start moving down |
| ? | Start moving in a random cardinal direction |
| _ | Pop a value; move right if value=0, left otherwise |
| | | Pop a value; move down if value=0, up otherwise |
| " | Start string mode: push each character's ASCII value all the way up to the next " |
| : | Duplicate value on top of the stack |
| \ | Swap two values on top of the stack |
| $ | Pop value from the stack and discard it |
| . | Pop value and output as an integer followed by a space |
| , | Pop value and output as ASCII character |
| # | Bridge: Skip next cell |
| p | A "put" call (a way to store a value for later use). Pop y, x, and v, then change the character at (x,y) in the program to the character with ASCII value v |
| g | A "get" call (a way to retrieve data in storage). Pop y and x, then push ASCII value of the character at that position in the program |
| & | Ask user for a number and push it |
| ~ | Ask user for a character and push its ASCII value |
| @ | End program |
| (space) | No-op. Does nothing |
go build -o fungus .
./fungus <file.bf>
NOTE: fungus will read from standard input if no arguments are passed
MIT