From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Naming convention to identify functions with side effects
Date: Mon, 29 Sep 2008 21:52:18 +0200
Date: 2008-09-29T21:52:22+02:00 [thread overview]
Message-ID: <h9civa1o39f6$.79cdhcp3sfms$.dlg@40tude.net> (raw)
In-Reply-To: 29ac62e1-78da-4048-ad95-8f88a29f7d31@z6g2000pre.googlegroups.com
On Mon, 29 Sep 2008 11:55:49 -0700 (PDT), Adam Beneschan wrote:
> It's this last that is connected to one of my pet peeves. Say you've
> decided to write a routine to load a particular web page, and you've
> made it a Boolean function that returns True if it's successful:
>
> function Load_Web_Page (URL : String) return Boolean;
>
> Several times, I've heard people say (in similar cases) that the name
> should be something like this:
>
> function Web_Page_Is_Loaded (URL : String) return Boolean;
>
> so that it's grammatically correct when you put it in an IF statement:
>
> if Web_Page_Is_Loaded ("http://www.irvine.com") then...
>
> This is WRONG, WRONG, WRONG!!! It may make your IF statement look
> more grammatically correct, but it OBSCURES what the program is
> doing. The above "grammatically correct" statement looks more like a
> check to see if the page is already loaded; a programmer reading this
> will not be able to figure out that the function call is the routine
> that actually does the loading. This is much better:
>
> if Load_Web_Page ("http://www.irvine.com") then...
I don't like either. They hide the side-effect instead of publishing it.
Is_Loaded is a property of a page, it is not of an URL. To me it should be:
type Web_Page is ...;
function Load (URL : String) return Web_Page;
function Is_Loaded (Page : Web_Page) return Boolean;
Should pages be cached, then the cache of pages must be exposed:
type Web_Page is ...;
type Web_Pages_Cache is ...;
procedure Load (Cache : in out Pages_Cache; URL : String);
function Is_Loaded (Cache : Pages_Cache; URL : String) return Boolean;
function Get_Loaded (Cache : Pages_Cache; URL : String)
return Web_Page;
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2008-09-29 19:52 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-29 18:17 Naming convention to identify functions with side effects Hibou57 (Yannick Duchêne)
2008-09-29 18:45 ` Hibou57 (Yannick Duchêne)
2008-09-29 18:55 ` Adam Beneschan
2008-09-29 19:52 ` Dmitry A. Kazakov [this message]
2008-09-29 20:48 ` Georg Bauhaus
2008-09-29 21:10 ` Adam Beneschan
2008-09-30 15:17 ` Georg Bauhaus
2008-09-30 17:40 ` Ray Blaak
2008-10-02 12:33 ` Ole-Hjalmar Kristensen
2008-10-03 9:18 ` Georg Bauhaus
2008-10-06 7:24 ` Ole-Hjalmar Kristensen
2008-10-03 11:51 ` Brian Drummond
2008-10-03 12:28 ` Dmitry A. Kazakov
2008-10-04 12:30 ` Marco
2008-10-04 13:05 ` (see below)
2008-10-04 15:14 ` Gary Scott
2008-10-11 11:32 ` Marco
2008-10-11 14:57 ` Dmitry A. Kazakov
2008-10-11 16:05 ` (see below)
2008-10-11 17:49 ` Georg Bauhaus
2008-10-11 18:42 ` (see below)
2008-10-03 13:15 ` Jeffrey Creem
2008-09-29 20:57 ` Georg Bauhaus
2008-09-29 22:22 ` Dr. Adrian Wrigley
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