Re: switch case - to require the break statements seems strange to me

On Sep 13, 2008, at 12:12 PM, Robert Cummings wrote:

On Sat, 2008-09-13 at 10:09 -0400, Eric Gorr wrote:

On Sep 12, 2008, at 5:13 PM, Robert Cummings wrote:

On Fri, 2008-09-12 at 16:51 -0400, Eric Gorr wrote:

On Sep 12, 2008, at 4:27 PM, Robert Cummings wrote:

On Fri, 2008-09-12 at 16:11 -0400, Eric Gorr wrote:

On Sep 12, 2008, at 3:44 PM, Robert Cummings wrote:

I don't see how that in any way makes an argument for or against. Once still must spend client's money wasting time on code that has questionable merit. Yes, some debugging code is a great boon in any application, but littered everywhere to fulfill someone's subjective philosophical ideal when sometimes it's just plain unnecessary... wasteful IMHO.

As far as I know, no one has yet come up with a proof showing when debugging code is and/or is not necessary. The simple fact is that bugs can popup anywhere and spending a client's time and money by spending a few minutes writing all of the simple test cases throughout an application can be well worth it as it can save far more of the client's time and money by not wasting it on tracking down bugs that could have been easily caught.

It is impractical to include debugging code for every conditional in a program.

I have yet to see any evidence that it is impractical, especially after one has gotten into the habit. After all, for switch statements, adding in a default case takes mere seconds.

Yes but if you do for case, you SHOULD do for if/else if/else which is an analagous approach.

Doubly impractical to do so in PHP unless you have some way to prevent said debugging code from running in production.

It isn't hard to prevent a code path from running in a production environment and allowing it to run in a development environment. Just one example, in PHP, would be globally defining something like PRODUCTION and then testing to see if it has a value of 1 or 0 and then writing an if statement to test the value before executing some code.

There you go... you just ran a useless branch. Replacing one code path with another is hardly an optimial solution. What if your case statement is in a tight loop that runs a million times?

How could that possibly matter since the code is never supposed to be executed to begin with and if it is executed it would immediately imply there is a bug?

This discussion started because you said put a default statement in for debugging purposes rather than leave it empty. This suggests that you have a finite number of case statements that handle a specific set of values and that there may be values that don't need handling. Since they don't need handling the optimal path is not to have a default statement, but you suggest adding one with debugging information even though no processing need occur for some values. Now do you understand? Just because you have a switch doesn't mean all values need handling.

Ah, while I had expected that my initial comments had been misinterpreted, I can see clearly now that they have. Hopefully, the messages the past couple of days have cleared things up.

Furthermore, the whole point of these test cases is for those parts of the code which are never supposed to be executed to begin with, so that alone will aid in preventing said debugging code from executing in production...and if said debugging code does run in production, would that be such a bad thing (assuming it doesn't interfere with the user)? After all, because it (like the default switch case) was executed, it immediately implies there was a problem...

If they're never supposed ot be executed then why are you adding extra code? That sounds like a need for better logic skills, not a need for debugging code.

Because, it is never supposed to be ... not never will be. Bug's cause all kind of things to happen...including code paths that aren't supposed to happen. I doubt any client would believe it a good thing that a bug that should have been caught in development wasn't caught until production because mere minutes weren't spent putting in debug code that would have caught these bugs.

You're probably one of those people that comments incrementing an index *shrug*. I mean it's mere seconds to add a useless chunk of comments that may someday help someone understand you're incrementing $i.

While there is certainly a time and a place for comments which answer the questions of 'How?' or 'What?', the most useful comments nearly always answer the question of 'why?'. Why? The questions of 'How?' or 'What?' can almost always be easily determined with an analysis of the code. However, such an analysis does not always lead to understanding why code was written in the way it was written and I would strongly recommend people adopt such a comment style. Oh, for those using SCM (Source Code Management - like subversion), this policy applies to the checkin comments as well. Answering the question of why a change was made is almost always far more useful then simply stating what was changed.

Similarly, for simplistic case statements, there's virtually no need for a block of debug code.

Unless, the block of debug code would catch a code path that should never be executed. Then, even for the simplistic case statements, such a block of debug code would be useful and could save a lot of time by catching a bug that may have taken hours to otherwise track down.