An implementation of an extended brainfuck interpreter in python. This extended version of brainfuck, called brainfunc, supports use of functions. Function are defined using the ( and ) operators and called with the * command.
| Command | Meaning |
|---|---|
> |
Increment the data pointer (to point to the next cell to the right). |
< |
Decrement the data pointer (to point to the next cell to the left). |
+ |
Increment (increase by one) the byte at the data pointer. |
- |
Decrement (decrease by one) the byte at the data pointer. |
[ |
If the byte at the data pointer is zero, then instead of moving the instruction pointer forward to the next command, jump it forward to the command after the matching ] command. |
] |
If the byte at the data pointer is nonzero, then instead of moving the instruction pointer forward to the next command, jump it back to the command after the matching [ command. |
(, ) |
Define a function inside (). Nested function definitions like (()) are not supported. |
* |
Call the function that has number == value of the byte at the data pointer. |
All other characters that are not commands are ignored.
The function are numbered following the order in which they were defined.
For instance, for the code input (+++)(->>[-<+>]<<)++<++++<+*, we define two functions and then execute the sequence ++<++++<+*, which sets the values 2 and 4 in the bytes at positions 0 and -1, then sets the value 1 at byte-position -2 and calls the function of index 1 (the second function: (->>[-<+>]<<)) by executing the * command. This code does the summation of the numbers 2 and 4.
( Try to figure out how this works :)
(->-<+<+<+<+++*[<++++*>++*>>>+<<<+++*])
(-->>[-<<+>>]<[->+<<+>]<[->+<])
(--->>>>[-<<<<+<+>>>>>]<<<<<[->>>>>+<<<<<]>>>>[-<<<-<+>>>>]<<<<[->>>>+<<<<]>)
(---->[-]<)
+++++++++++++++<+*