Mapping operator tokens to special methods

[jamesthiele.usenet at gmail.com]

I was starting to write a dictionary to map operator strings to their
equivalent special methods such as:
{
  '+' : 'add',
  '&' : 'and_'
}

The idea is to build a simple interactive calculator.

and was wondering if there is already something like this builtin?

Or is there a better way to do what I want?