Re: invertability and idempotence

> > didn't want to introduce new terminology. But referring to this:
> > 
> > >    generate(parse(msg)) == msg
> > 
> > as "idempotency" is perfectly valid in my opinion (as in, applying an
> > operation multiple times produces the same result). 
>
>That would be generate(generate(msg)) == generate(msg) or
>parse(parse(email)) == parse(email).  The input and output of
>these functions are of *different types*, they cannot possibly be
>idempotent.

You're splitting hairs - the operation "generate(parse(X))" is idempotent,
and that's what I was referring to. 

-- 
Andrew McNamara, Senior Developer, Object Craft
http://www.object-craft.com.au/