I think it's clearer to not have $ imply negation, so that $-x can really be thought of as the subtraction sizeof(the string) - x. But that's a question of taste, I guess.
/ Niels Möller (med röd bil)
Previous text:
2003-05-16 00:28: Subject: Negative ranges revisited
Looks good to me. The operator could imply the negation, so that it's only e.g. foo[$3..$1]. Maybe the negation is good for clarity, but otoh it could easily be taken for a binary substraction and that the $ is a term.
$ has a slight drawback in that it's often treated as a symbol building character, typically used in machine generated symbols.
/ Martin Stjernholm, Roxen IS