This is my first esoteric language, which I decided to call
L00P. These are the specs:

- L00P programs operate on a pointer (p) to an array of ARRAYSIZE
  16-bit signed ints (a) which are set to 0 before the program
  is started (ARRAYSIZE == 8192 in this implementation).
- There is an implicit loop around each L00P program (hence
  the name) which can only be left with the '&' instruction.
- Comments start with "//" and go to the end of the current line.
- The memory array is circular.
- Whitespace is ignored.
- Non-instruction-characters outside a comment are stripped away.


Instructions:

             , . input/output a[p] as character
             < > p-- /  p++
             - + a[p]-- / a[p]++

             (These instructions have been borrowed from the Brainf*** language) 

             ; : input/output a[p] in decimal notation.
               0 a[p] = 0
               * a[p] *= 2
               _ a[p] = - a[p]
               # p    = p + a[p]
               @ a[p] = a[p + a[p]]
               $ a[p + a[p]] = a[p]
               & terminate program
               S A = sign (A)
 (code1 | code2) if a[p] code1 else code2
 [code1 | code2] syntactic sugar for (code2 | code1)

- Note that the "else" branches ("| code2") are optional.



Examples:

[;>+**+*](<:[&]->:) 
// Input positive number n , count down from n to zero

[;>;>--@>--@>+](<<<<[>>:&|>[>>:&|<->->>>]]
// Input positive numbers x and y, print min(x,y)

[+**+*>-@+**+>;>-@S+[<_>]-<<](>[:<<.&]>+[<<.>>]-<:-<<.>)
// Input any number n, count up/down from n to zero