If you haven’t heard about Brainfuck yet, it is a famous esoteric programming language. If you want to know why it has such a name take a look at its hello-world program source code (from Wikipedia):
+++ +++ +++ + initialize counter (cell #0) to 10
[ use loop to set the next four cells to 70/100/30/10
> +++ +++ + add 7 to cell #1
> +++ +++ +++ + add 10 to cell #2
> +++ add 3 to cell #3
> + add 1 to cell #4
<<< < - decrement counter (cell #0)
]
>++ . print 'H'
>+. print 'e'
+++ +++ +. print 'l'
. print 'l'
+++ . print 'o'
>++ . print ' '
<<+ +++ +++ +++ +++ ++. print 'W'
>. print 'o'
+++ . print 'r'
--- --- . print 'l'
--- --- --. print 'd'
>+. print '!'
>. print '\n'
the above program can be written as:
++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.
So now you should know how lovely the language is and why I need to write a interpreter in Flash: now you can manipulate a ByteArray with BrainFuck code!!! And ya, the name of my interpreter is even more friendly than the language’s name! :)
Here is the result demo (source code here), type in a program and its input then click run. The default program is to add up two single-digit integers. And the output is correct only if the sum is single-digit too. And again the code is from Wikipedia. You may find other BrainFuck source code to test from Panu Kalliokoski’s Brainfuck Archive.
The interpreter is written by only looking at its command description. There are some bugs as I know. For example when inputting multiple lines, the output may have wrong formatting. And it can not have dynamic input like having inputs in a infinite loop. Actually any infinite loop will freeze your browser.
I don’t think I will go to improve it anytime soon. So please, don’t use it in production (will anyone??).