BrainFart

BrainFart is my implementation of the one and the only BrainFuck.

Instructions

Opcode	Description
<	Move to the previous cell on the tape
>	Move to the next cell on the tape
-	Decrement the value of the current cell
+	Increment the value of the current cell
,	Read one byte of input from stdin and store it inside the current cell
.	Write the value of the current cell to stdout
[	If the value of the current cell is 0 then jump to the instruction after the matching ]
]	If the value of the current cell is not 0 then jump to the instruction after the matching [
{	Define a function identified by the value of the current cell and jump to the instruction after the matching }
}	End function definition
\	Return from function
@	Call the function identified by the value of the current cell

Extensions

In order to support functions BrainFart implements three additional instructions that are not present in BrainFuck:

1. {: Def
2. }: End
3. \: Ret
4. @: Call

Implementation details

• 8 bits cells
• wrapping on owerflows
• unlimited tape size (on both directions)
• Zero on EOF
• When a function gets defined/called the value of the current cell will be set to 0
• Functions can be redefined: at the start of the program every function is defined as noop
• Since cells are used to identify functions the maximum number of functions allowed is 256: from 0 to 255
• return from outside of any function terminates execution (if not in interactive mode)