> From: Ian Whitlock [mailto:WHITLOI1@WESTAT.COM] > I think you are missing the point that global variables are > poor way to > design complex code systems. Each time a macro uses a global > variable one > of the conditions required for proper operation of the macro > is left hanging loose with no indication of its origin.

Yes, I have to agree with that statement. This is why I suggested that the readonly status be allowed to be set in only one place, i.e., the autoexec.

> I don't know that having constant variables is bad and I can > imagine some might feel more secure with them.

Peace of Mind, for me, is soft-coding, rather than hard-coding. Each time I have had to change a hard-coded reference in my dozen projects' umpteen files, I have changed the reference from hard- to soft-coded references using %global macro variables.

My favorite example Monday morning lasted until Wednesday 3pm, when the SysOps changed the LAN drive letter where all my projects were stored from R to U. This is when I found that UltraEdit could open 100 files, and do a Find&Replace in All Open Files :-) and I needed to change 128 files. :-\

> However, I would far more prefer evolving > to a system where one can pass arguments by value > and guarantee that nothing passed to a helping macro > can be modified by the helper in the callers space.

I agree that this is Good Coding Practice.

However, you and I know we work with people whose eyes glaze over when they read your statement above. And we will have to fix their Coming-Up-to-Speed Coding Practices.

> The real question is just how much improvement > one can ask for in a macro language. > It's very implementation simplicity argues against > it ever being very easy to use.

LOL "Too much of a Good Thing, is still a Good Thing." -- Mae West

Ah, The SAS Macro Language: Very Simple. Therein lies its power: good small tools, with which we build Bigger&Better Tools. Which we don't want to drop on our, or anyone else's, feet.

> (Macro knows nothing about SAS and vice versa.)

<sigh> much to our chagrin.

Ron Fehd the macro maven CDC Atlanta GA USA RJF2@cdc.gov

By using your intelligence you can sometimes make your problems twice as complicated. -- Ashleigh Brilliant