I don't understand. Using your language, it must then be number2number, since a perl string of 0s and 1s is no more 'bin' than a string of 0s-9s is a 'dec'.

IMHO it's a matter of definitions, and on what abstraction level you think about it. I think about a string of 0s and 1s as a binary number in my internal represenation. The same way, I think about a string of 0s - 9s as a decimal string in my internal representation.

What Perl does for me is just print ASCII characters on the screen.