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From: jasonf@cetemp.Eng.Sun.COM (Jason Freund)
Newsgroups: sun.tech,comp.lang.pascal
Subject: Sun Pascal 2.0 array storage
Keywords: Sun array
Message-ID: <140332@sun.Eng.Sun.COM>
Date: 7 Aug 90 23:57:10 GMT
Sender: news@sun.Eng.Sun.COM
Followup-To: jasonf@cetemp.Corp.sun.com
Lines: 36


	I'm writing a program in Sun Pascal V2.0 that uses 1 giant
datastructure to hold the data for the entire program.  For several
reasons, irrelevant to this question, I chose to use only arrays and records.
No recursive datastructures.  At the lower levels of the structure, most
arrays are of type "varying" -- a char array that is alway = '' until you
give it something -- it's never bigger than the string it contains.

	My question is how much memory do various datastructures occupy?
If I have:  (just an analogy of my program.)

paragraphs = array [1..10] of varying;
pages = array [1..5] of paragraphs;
chapter = array [1..20] of pages;
book = array [1..10] of chapters;

How much memory am I wasting?   The varying at the bottom shouldnt be too
much of a problem -- although there are 10*20*5*10 of them, most of them are
empty (nil).  There are 10*20*5 pages -- mostly empty, 10*20 chapters,
mostly empty, etc.  So given that the varyings don't take up too much space and 
everything else is ~50-60% empty, how much memory will I be using, how much am
I wasting?

(PS.  I know that all of the above should be linked lists so that remaining blanks
in the book don't use up memory until they're written, but for now, I don't want
to use LLs -- I may later, but for now, I'm just curious.)

Thanks,
Jason Freund, Sun Microsystems,  jasonf@cetemp.Corp.sun.com  <== summer address
Deprtmnt of Computer Science, Univ California, Davis. freund@sakura.ucdavis.edu
Quantum Link: JasonF5,  Compu$erve: 72007,244, 690 Erie Dr, Sunnyvale, CA 94087
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