[Python-Dev] A Hygienic Macro System in Python?

[Skip Montanaro]

    Tom>   define macro unless
    Tom>     { unless (?test:expression) ?:body end }
    Tom>      => { if (~ ?test) ?body end }

    ...

    Tom> I find using 'unless' makes some things more readable. To learn the
    Tom> internals of the compiler I've been adding an unless statement to
    Tom> Python, but one shouldn't need to do this in order to add useful
    Tom> constructions like this.

Try this on for size:

    http://groups.google.com/groups?hl=en&ie=ISO-8859-1&oe=ISO-8859-1&frame=right&th=e4809653296a3b71&seekm=mailman.1016132066.3225.python-list%40python.org#link1

It may allow you to do some things like unless without messing around with
the compiler proper, though it is clearly nothing more than a neat little
hack.

Skip