comp.lang.ada
 help / color / mirror / Atom feed
From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: GNAT: Performance of String functions
Date: 1997/07/20
Date: 1997-07-20T00:00:00+00:00	[thread overview]
Message-ID: <dewar.869405750@merv> (raw)
In-Reply-To: 33D1D2BB.2023@online.no


Tarjei said

<<As unbounded strings are allocated on the heap there is a potential
serious overhead in allocating and deallocating space for these strings
as they change size. The serious overhead can include system calls to
allocate or free space. I expect that it also include wholesale copying
of the contents of the strings.
>>

Right, that is generally true, we have considered, but not yet implemented,
a version of unbounded strings that would allocate a little growth space
in each string value so that, for example, if you are adding one character
at a time, you do not copy on every addition. I think this would be a
valuable improvement.

Your message sure does become clearer when we put the "un" into it at
the appropriate points, and what you say is quite right.

In any case the bottom line here is that the original posters comparison
was inappropriate. A comparison with VAX strings should use bounded
srtings, not unbounded strings





  reply	other threads:[~1997-07-20  0:00 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-07-18  0:00 GNAT: Performance of String functions Jakob Heinemann
1997-07-18  0:00 ` Robert Dewar
1997-07-19  0:00   ` Tarjei T. Jensen
1997-07-19  0:00     ` Matthew Heaney
1997-07-20  0:00     ` Tarjei T. Jensen
1997-07-20  0:00     ` Robert Dewar
1997-07-20  0:00       ` Tarjei T. Jensen
1997-07-20  0:00         ` Robert Dewar [this message]
1997-07-21  0:00           ` Tucker Taft
1997-07-21  0:00             ` Robert Dewar
1997-07-21  0:00             ` Tarjei Jensen
1997-07-21  0:00               ` Matthew Heaney
1997-07-22  0:00               ` Robert Dewar
1997-07-22  0:00                 ` Tarjei Jensen
1997-07-22  0:00                   ` Larry Kilgallen
1997-07-22  0:00                     ` Tarjei T. Jensen
1997-07-23  0:00                       ` Larry Kilgallen
1997-07-23  0:00                       ` Robert Dewar
1997-07-23  0:00                         ` Tarjei Jensen
1997-07-23  0:00                           ` Samuel Mize
1997-07-23  0:00                             ` W. Wesley Groleau x4923
1997-07-24  0:00                             ` Robert A Duff
1997-07-24  0:00                           ` Mats Weber
1997-07-24  0:00                             ` Matthew Heaney
1997-07-24  0:00                             ` Tarjei Jensen
1997-07-24  0:00                               ` Robert Dewar
1997-07-24  0:00                               ` Matthew Heaney
1997-07-24  0:00                             ` Robert Dewar
1997-07-28  0:00                               ` Mats Weber
1997-07-28  0:00                                 ` Matthew Heaney
1997-07-29  0:00                                   ` Robert Dewar
1997-07-28  0:00                                 ` Robert Dewar
1997-07-28  0:00                                   ` Robert Dewar
1997-07-22  0:00                   ` Robert Dewar
1997-07-22  0:00   ` Jakob Heinemann
1997-07-23  0:00     ` Robert Dewar
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox