OpenEuphoria

Fwd: Re: Commabominations

• Posted by George Henry <ghenryca at HOTMAIL.COM> Jan 22, 2001
• 559 views

Hmm, looks like I misunderstood what "null" was all about. Find an
explanation below.

George

----Original Message Follows----
From: "Everett L.(Rett) Williams" <rett at gvtc.com>
To: ghenryca at hotmail.com
Subject: Re: Commabominations
Date: Sun, 21 Jan 2001 14:39:41 -0600

Geo,

"Regarding Rett's suggested use of "null", like all made-up variable
names it would tend to be redeclared, which is an error. So what do
you do, reach for names like null01, null02, etc? Sorry, I don't find
that approach satisfying either, although I like the word "null" in
this context better than the others that have been mentioned. "

Ye jumped the gun on me again. Remember, this is supposed to be an elegant
solution. Null is a special variable that is what it says. It's name defines
it's contents. It can be declared as often as necessary. I probably should
have called it a special constant, but I want it to be
useable in all definition strings:

sequence
      a,
      b,
     c,
     null
atom
     a1,
     b1,
     c1,
     null

"null" would never have to be initialized and it could not be the target of
any assignment. If one wished to allow it to be assigned, it could
cause the deletion of any variable, allowing immediate garbage collection.
This would allow a little user control of the garbage collector.

"null" could also be used as a placeholder for coding so that one can code a
procedure or function with nothing but null in it's body. The null would
cause a warning at run time that could be ignored or suppressed. Null can be
distinguished from empty in fully implemented
SQL systems and the distinction can be useful for saving space in data
bases. Accounting for the distinction is already implicit to Euphoria. All
declared Euphoria variables are null until they are initialized if I
understand them correctly. If null is to be used for more than syntactic
purposes, then a test for it must be added to the language. As I have set it
up above, no such test is needed, because no working variable may have it's
value.

Everett L.(Rett) Williams
rett at gvtc.com





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