functions

[Richard Bos]

So the important distinction is between those that shuffle bits, and
those that perform actions.

And those that shuffle bits and then perform an action with them, and
those that perform an action and then shuffle the resulting bits. And
even, rarely, those that neither shuffle bits nor perform any actions -
sometimes the purpose of a function is just to exist.

Richard

 

[Malcolm McLean]

And those that shuffle bits and then perform an action with them, and
those that perform an action and then shuffle the resulting bits. And
even, rarely, those that neither shuffle bits nor perform any actions -
sometimes the purpose of a function is just to exist.

All procedures shuffle bits (I suppose someone will come up with an
exception).

You can have a null function, that is true. The object in
distinguishing functions from procedures is to come up with a
separation for the purposes of software engineering, which is partly a
psychological discipline, not to produce a formal set theory of
functions.