Path: utzoo!mnetor!uunet!husc6!bbn!mit-eddie!rutgers!columbia!convent!fox
From: fox@convent.columbia.edu (David Fox)
Newsgroups: comp.lang.c++
Subject: Re: access functions
Message-ID: <5547@columbia.edu>
Date: 21 Apr 88 16:44:02 GMT
References: <8063@apple.Apple.Com> <6590039@hplsla.HP.COM> <11152@mimsy.UUCP>
Sender: nobody@columbia.edu
Reply-To: fox@convent.columbia.edu (David Fox)
Followup-To: comp.lang.c++
Organization: Columbia University Computer Science Dept.
Lines: 25

In article <11152@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>The point, however, is that a variable is always
>a variable, while a function is arbitrary.  So if you declare that
>henceforth and forever, anyone can take complexvar.realpart() and
>complexvar.imaginarypart(), and you decide you prefer polar coordinates,
>people can still take the two, while if you declare that anyone
>can simply take .realpart and .imaginarypart, you are stuck with
>rectangular.

There is really no need for the parentheses after a function that
takes no arguments.  Envision a preprocessor which builds the
symbol table for the program and, when it runs across an identifier
which is defined as a function taking no arguments, adds the parentheses.
This could also be added to a c++ compiler (or even to a C compiler).
Then you could start with a public member and later change it to an
access function without hosing your clients.

Some might say that the parens are a clue to the object's type, but
is this important?  I say that a variable really *is* a restricted
form of a function that takes no arguments.  If something is called
'imaginary_part' then it *is* (or ought to be) the imaginary_part,
regardless of what machinations occur during its evaluation.

David Fox
fox@heathcliff.columbia.edu