Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site watmath.UUCP
Path: utzoo!watmath!idallen
From: idallen@watmath.UUCP
Newsgroups: net.cog-eng
Subject: Re: expert-friendly: are long names a waste of time?
Message-ID: <6072@watmath.UUCP>
Date: Thu, 3-Nov-83 21:52:40 EST
Article-I.D.: watmath.6072
Posted: Thu Nov  3 21:52:40 1983
Date-Received: Fri, 4-Nov-83 09:23:06 EST
References: <1367@utcsstat.UUCP>, <465@dciem.UUCP>
Organization: U of Waterloo, Ontario
Lines: 36

I agree with Martin Taylor when he says remembering the order of
arguments is difficult.  I don't think his answer, have the computer
try to interpret the order, will work well.  Continuing his example:

    echo hi >755  ;  echo ho >644  ;  chmod 644 755

The computer can't figure out which argument order I mean in this
(contrived) case.  Nor can it figure out if I replace CHMOD with CP.

If two (or more) different things have to be given as command arguments,
then the order of two things can get confused.  Some way is needed
to flag which kind is which.  The easiest thing on the brain is:

    ***************************************************************
    ***> Don't allow more than one kind of unflagged argument. <***
    ***************************************************************

I would rewrite CHMOD as follows (the order of arguments doesn't matter):

    change_file_mode [mode=]755 [filename=]/u/idallen/myfile

where either "mode=" or "filename=" *must* be present to tell the
command which kind of argument is which.  A repaired example:

    change_file_mode 644 mode=755             /*OKAY*/
    change_file_mode filename=644 755         /*OKAY*/
    change_file_mode m=755 f=644              /*OKAY*/
    change_file_mode 644 755                  /*NO GOOD*/

Never rely on position (first, second, last, etc.) to determine what
will be done with an argument.  Require the user to make explicit which
types of arguments are which, and then order doesn't matter.  The
arguments can be flagged and typed in as the user sees fit, and the
user's perception of which argument "should" come first doesn't matter.
-- 
        -IAN!  (Ian! D. Allen)      University of Waterloo