RE: [PEAR-DEV] Re: DB Exceptions - Sample Code

I added a sample DB_Exception class tree to the code. http://www.cerad.org/pear/index.php -----Original Message----- From: Lukas Smith [mailto:lsmith@php.net] Sent: Friday, July 09, 2004 9:22 AM To: Hans L Cc: Sergio Carvalho; pear-dev@lists.php.net Subject: Re: [PEAR-DEV] Re: DB Exceptions - Sample Code Hans L wrote: > Lukas Smith wrote: > >>> It's a good point that inheritance trees are a more powerful type of >>> classifiction. You can represent generalities & relationships in a >>> way that isn't possible with the codes. And certainly these >>> subclasses can store specific information, which makes the argument >>> re: empty subclasses go away. >> >> >> >> Well lets say you can define them in a more straightforward way. You >> can define a system of how error codes are to be named that enables >> classification in much the same way. Defining these rules is quite a >> task however. The advantage is that once you have it, those people who >> now this ruleset can quickly get alot of information by just looking >> at the error code itself, whereas its alot more difficult to remember >> full inheritance trees if you use them for classification. I dont have >> experience defining anything like that, so I will refrain from giving >> an example for now. However the SQL standard for example defines such >> an error code classification IIRC. >> > > You can certainly categorize / classify error codes in some sort of > hierarchy system, but the point of using the class hierarchies is not > for readability (we have messages for that) but so that you can > selectively catch() these errors in your scripts, or catch() groups of > errors, etc. I can't think of a more natural way of representing > hierarchy in OO languages. So, if hierarchy is important to error > codes, exception subclasses seem the way to go. If the error codes are > flat then I'd probably use error codes -- if anything. Depends on the > package, I feel. You forget that we dont only execute but also read code. So if you categorize by hirarchy you end up with insanely long names. Anyways the point i was trying to make is that you can categorize using error codes and that error codes are a very concise string which people in the know can levarage to get alot of information from a tiny string. Of course for the unwashed it must be easy to look them up in a mapping table. Note what I am talking about here has nothing to do with code that is being executed, since a machines are not affected by this issue (in this context the length of an error code or the depth of an inheritance tree are not relevant issues). regards, Lukas -- PEAR Development Mailing List (http://pear.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php