Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.java.programmer > #3912

Re: About using assertion

Path csiph.com!x330-a1.tempe.blueboxinc.net!aioe.org!texta.sil.at!newscore.univie.ac.at!aconews-feed.univie.ac.at!aconews.univie.ac.at!not-for-mail
Newsgroups comp.lang.java.programmer
From Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at>
Subject Re: About using assertion
References <f1e4cc83-8596-4e53-bed7-34a5209fe8c4@k3g2000prl.googlegroups.com> <09cb7d90-9b79-473e-9869-4476c5a0191a@w24g2000yqb.googlegroups.com> <hp3gs6dun3691h96q13jsb6sb4pu0rrvrp@4ax.com> <iq93mt$7ob$1@news.albasani.net> <92r0e9F6lvU1@mid.individual.net> <iq9r2h$tlh$1@news.albasani.net> <lP7yp.31027$vC5.15267@newsfe01.iad>
Reply-To avl@logic.at
User-Agent slrn/pre0.9.9-111 (Linux)
Mime-Version 1.0
Content-Type text/plain; charset=us-ascii
Content-Transfer-Encoding 7bit
Message-ID <slrnisifel.phi.avl@gamma.logic.tuwien.ac.at> (permalink)
Date 10 May 2011 13:29:57 GMT
Lines 28
NNTP-Posting-Host gamma.logic.tuwien.ac.at
X-Trace 1305034197 tunews.univie.ac.at 60386 128.130.175.3
X-Complaints-To abuse@tuwien.ac.at
Xref x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:3912

Show key headers only | View raw


Arved Sandstrom <asandstrom3minus1@eastlink.ca> wrote:
> On 11-05-09 07:49 PM, Lew wrote:
>> There is art in the decision of which invariants to document.  I like to
>> document all of them.  Why not?

"All" does sound a bit harsh, doesn't it? Would you really do even:
  if ( xyz != null ) {
     assert xyz != null : "Something's wrong with the world...";
     ...
  }
? ;-)

> On a related note, when I run into
> objections about use of assertions, let alone copious use of them, the
> most frequent objection is that they'll "break" the program.

Bad assertions *can* break the program in nasty ways:
  assert methodWithRelevantSideEffect() > 0 : "Aww...";

Another caveat is, if one uses assert reasonably but then by some
mistake assertions are unexpectedly turned off:
 "We'd have got an assertion failure here, so it must have gone there ..."

Nothing of this post shall be construed as a discouraging against
reasonable use of assertions.  But they *are* part of the code, and by 
adding them, code size grows, and bug-likeliness is also proportional
to code size.  Adding assertions *can* be overdone.

Back to comp.lang.java.programmer | Previous | NextPrevious in thread | Next in thread | Find similar


Thread

About using assertion byhesed <byhesed@gmail.com> - 2011-05-09 07:36 -0700
  Re: About using assertion Robert Klemme <shortcutter@googlemail.com> - 2011-05-09 08:24 -0700
    Re: About using assertion Roedy Green <see_website@mindprod.com.invalid> - 2011-05-09 09:01 -0700
      Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-09 12:11 -0400
        Re: About using assertion Robert Klemme <shortcutter@googlemail.com> - 2011-05-09 22:17 +0200
          Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-09 18:49 -0400
            Re: About using assertion Robert Klemme <shortcutter@googlemail.com> - 2011-05-10 07:23 +0200
            Re: About using assertion Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-10 06:45 -0300
              Re: About using assertion Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-05-10 13:29 +0000
                Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-10 11:21 -0400
                Re: About using assertion Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-05-10 16:01 +0000
                Re: About using assertion RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-05-10 17:26 +0100
                Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-10 13:25 -0400
                Re: About using assertion Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-10 21:15 +0200
          Re: About using assertion tmcd@tmcd-p4-linux.austin.tx.us (Tim McDaniel) - 2011-05-19 00:32 -0500
            Re: About using assertion Michal Kleczek <kleku75@gmail.com> - 2011-05-19 08:34 +0200
              Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-19 08:46 -0400
                Re: About using assertion Michal Kleczek <kleku75@gmail.com> - 2011-05-19 15:16 +0200
                Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-19 09:38 -0400
                Re: About using assertion Robert Klemme <shortcutter@googlemail.com> - 2011-05-19 07:41 -0700
                Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-19 11:00 -0400
            Re: About using assertion Patricia Shanahan <pats@acm.org> - 2011-05-19 05:52 -0700
              Re: About using assertion tmcd@tmcd-p4-linux.austin.tx.us (Tim McDaniel) - 2011-05-21 18:37 -0500
                Re: About using assertion Patricia Shanahan <pats@acm.org> - 2011-05-21 19:00 -0700
                Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-22 01:19 -0400
  Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-09 11:35 -0400
  Re: About using assertion markspace <-@.> - 2011-05-09 11:40 -0700
    Re: About using assertion Lew <noone@lewscanon.com> - 2011-05-09 14:53 -0400

csiph-web