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Re: macro conventions

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On Sun, 15 May 2011 06:50:54 -0700, Keith Thompson <kst-u@mib.org>
wrote:

>ralph <nt_consulting64@yahoo.net> writes:
>[...]
>> The actual 'rules' and conventions are more complicated and others
>> will be along shortly to quote chapter and verse. However, in order to
>> avoid collisions, best practice is simply never create a macro with an
>> underscore for your own use and use always use uppercase.
>
>TO be clear, it's leading underscores that should be avoided.  FOO_BAR,
>for example, is perfectly ok.  Trailing underscores are also ok, though
>I wouldn't use them without a good reason.

Thanks for that catch. I did make it sound like underscores should be
avoided throughout an identifier, when they are in fact OK. 

It should also be amplified that double underscores "_ _" are reserved
even within or trailing an identifier

     FOO_BAR is OK, FOO__BAR or FOOBAR__ is not.

Luckily most collisions are grievous enough to become quickly
identified during development. Real trouble often comes about, not
from using underscores per se, but from using certain keywords,
letters, or library tags as prefixes. For example, many years back I
remember a team getting tangled up with macros beginning with "E_",
"SIG_", "XL_", and "H_".

The problem in that case was not the few hours lost to development to
go back and clean it up. It was the endless ugliness that came about
because some pointed-hair boss decided that to avoid all future
collisions, all macros would be defined as ...

      ABC_Co_FOO_BAR,
      ABC_Co_Inventory_FOO_BAR,
      ABC_Co_Errors_FOO_BAR,
      ABC_Co_HeaderFile_FOO_BAR
      ...

Moral of the story: If you are working on a team and have a collision
- fix it AND keep your mouth shut. <bg>

-ralph

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macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-13 12:56 -0400
  Re: macro conventions pete <pfiland@mindspring.com> - 2011-05-13 13:08 -0400
  Re: macro conventions Shao Miller <sha0.miller@gmail.com> - 2011-05-13 13:14 -0400
    Re: macro conventions Keith Thompson <kst-u@mib.org> - 2011-05-13 11:41 -0700
      Re: macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-14 23:08 -0400
  Re: macro conventions ralph <nt_consulting64@yahoo.net> - 2011-05-13 13:15 -0500
    Re: macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-14 23:11 -0400
    Re: macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-15 04:00 -0400
      Re: macro conventions Angel <angel+news@spamcop.net> - 2011-05-15 11:15 +0000
        Re: macro conventions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-05-16 04:36 +0300
          Re: macro conventions Ike Naar <ike@sverige.freeshell.org> - 2011-05-16 09:56 +0000
            Re: macro conventions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-05-16 19:00 +0300
            Re: macro conventions Seebs <usenet-nospam@seebs.net> - 2011-05-16 19:10 +0000
              Re: macro conventions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-05-22 21:27 +0300
    Re: macro conventions Keith Thompson <kst-u@mib.org> - 2011-05-15 06:50 -0700
      Re: macro conventions Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-05-15 08:29 -0700
        Re: macro conventions Ian Collins <ian-news@hotmail.com> - 2011-05-16 07:40 +1200
          Re: macro conventions "osmium" <r124c4u102@comcast.net> - 2011-05-15 14:52 -0500
      Re: macro conventions ralph <nt_consulting64@yahoo.net> - 2011-05-16 02:22 -0500
        Re: macro conventions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-16 14:18 +0100
          Re: macro conventions David Resnick <lndresnick@gmail.com> - 2011-05-16 08:03 -0700
            Re: macro conventions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-16 17:32 +0100
        Re: macro conventions Keith Thompson <kst-u@mib.org> - 2011-05-16 08:43 -0700
          Re: macro conventions Michael Press <rubrum@pacbell.net> - 2011-05-16 14:47 -0700

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