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Best and Worst Coding Standards?
An anonymous reader writes "If you've been hired by a serious software development house, chances are one of your early familiarization tasks was to read company guidelines on coding standards and practices. You've probably been given some basic guidelines, such as gotos being off limits except in specific circumstances, or that code should be indented with tabs rather than spaces, or vice versa. Perhaps you've had some more exotic or less intuitive practices as well; maybe continue or multiple return statements were off-limits. What standards have you found worked well in practice, increasing code readability and maintainability? Which only looked good on paper?"
I've worked where we were supplied a full IDE and a 17" CRT, and the coding standard forced so much white space vertically that you had to basically remember all the code.
I can't stand seeing the closing brace of an if statement sharing a line with an else, like so:
if( condition ) {
statement1;
} else {
statement2;
}
I've always found the Joint Strike Fighter's coding standards document an interesting read. It is available from Bjarne Stroustrup's website (pdf)
This sounds like a fairytale but I work for a very large IT firm which is very well known. Serious company doesn't mean good however.
In certain files (not all apparentely) all constant variables have to be declared globally. We are talking C++ here.
Think what you want, but I don't like it. The reason for the variables placements are so "that they will be easy to find".
My new standard comes from a 1950's comp sci book.
"Programs consists of input, output, processing and storage."
Lose focus of that and the project will be late, over budget and most likely broken in ways no one will understand for years.
One of my friends worked at a place where you'd have to insert whitespace to place certain elements (variables, evals, etc.) to begin at a specific col in the code within every line; in addition to standard indentation of the line. At one level, I see the concept, but seriously - highlighting and search is made to solve the same problem there.
He left that job quickly.
Returned Peace Corps IT Volunteer
Also found I prefix in .NET really bad pracitce for marking interfaces like ICollection, what about when You decide turn interface to abstract class?..
Well. The whole point of having interfaces is allowing the implementation of a certain method set to the world, which later can be used in your APIs using polymorphism. If you later decide to break the contract and make an interface a class, then probably a name change (made also automatically in tools like Eclipse or NetBeans) won't be any worse.
As for the Hungarian notation, the standard form is indeed worthless. But we tend to use simple maximum three letter abbreviations of Swing components, to know that we are taking the username from txtLogin and listening for pressing btnOK. Code is more often read than written and this quasi-Hungarian style actually works pretty well.
In fact, having interfaces named like "IPasswordProvider" is something very similar. It enables easy reading of your code and when you want to make a change, you instantly see that this type is an interface, therefore you cannot instantiate it directly, but you can implement this interface in any arbitrary class you may already have written, etc. Plus, Sun coding standards encourage you to name interfaces in a passive adjective way like "Serializable", "Comparable", etc. To comply with this format is not very natural for interfaces like "IPasswordProvider" or "IModelContext".
Build a tool even an idiot can use and only an idiot will want to use it. -S.O.B.
I worked for a company that was destroyed by a bad coding standard.
This was a small company, that, back in '96, was awarded the contract for a POS application for a regional store chain, with back-office servers that would be updated nightly by modem.
The guys who ran the company weren't programmers (though one of them knew enough to be dangerous); they were technical salesmen. They were also big fans of Microsoft, with "MVP" plaques on the walls, and every employee except me having Microsoft certs.
I worked for them part-time while also working for another company. I advocated Unix (mostly BSDI and SunOS at the time), and always argued with them about why Unix was better (technical superiority vs. potential for big profits).
When their big project was well underway, they brought me in to do the communications part of it, where the POS terminals would contact one of several servers by modem each night ("why not just ethernet them together, get a dialup PPP connection, and use IP? the interface is so much more reliable..." Request denied).
The app was Visual Basic, with third-party "custom controls" for things like talking to modems. My part went fairly smoothly, and I was eventually asked to help out with the main application, which was suffering from unexplained crashes. When I looked at the code, I found something... strange.
For error handling, they had elected to use a program called "VB Rig" (the name came from the rigging used on sailing ships, which prevents a sailor from falling to his death. Sometimes.) What this program did was to examine the source code, and then add error handling boilerplate at the start and end of each and every function. It inserted the exact same error handling code into every function.
Because the error handler had to be all purpose, it was about 20 lines of code per function - sometimes much larger than the regular part of the function. And, worse, because it was the same for every function, and it made use of the same variable names, that meant either every variable had to be global, or you'd have to declare the ten or so standard variable names at the start of every function (they opted for the "everything is global" approach).
Which led to things like this (forgive the syntax errors, it's been years since I've touched VB):
On Error goto my_data_file_read_function_VBRIG_TRAP
open MyDataFile for writing ...
goto my_data_file_read_function_VBRIG_CLEANUP
my_data_file_read_function_VBRIG_TRAP:
on error 101 'Permission Denied
delete MyDataFile
resume
on error 102 'File Not Found
MessageBox 'Cannot read ' + MyConfigFile
resume
my_data_file_read_function_VBRIG_CLEANUP:
blah blah
my_data_file_read_function = SUCCESS ' return
As you see, the error handling code - which had to be exactly the same for every function - made use of global variables (names like DataFile1, MyFile1, UserName, etc.) to figure out what to do for each error. That meant, that if there was any possibility you might have a "File Not Found", you had to expect the filename where that might happen to be in a particular global variable - say, MyFile1 - and hope that the calling function wasn't using that name too, for the same reasons.
Naturally, files were being created and deleted at random, and the programmers often spent hours on the phone with the customer trying to figure out why the Access database had disappeared *again*.
I asked if we could just write the error handling by hand, and use appropriate local variables; or take the standard VBRig error handling and trim out the lines that weren't relevant for a particular function (as subsequent VBRig runs wouldn't touch its code region if it saw that it had been customized).
Request Denied. "This is our coding standard. We carefully reviewed the options before making the decision to use t
On the strange side is the omission of vowels on functions and varible names to save text space (it's not required, but should be consistent for similarily names objects). It sounds weird, but is still quite readable.
multiple return statements were off-limits
Despite the fact that it's not part of the coding standard where I work, I have a few coworkers who take this to the extreme. They surround every single function they write with: ... } while(0);
do{
And then, inside the "do" block, they just put "break" in any place where they would have otherwise put "return." It drives me insane; they insist that having a single exit point from your function makes it easier to debug, but I just don't get it. I've never even seen them use gdb, anyway, so I think that abusing "printf" is their idea of "debugging"...
One thing in our coding standard that I do like is that all variables that store units must have a unit specification at the end of their name -- in other words, all frequencies might have "Hz" or "MHz", distances might have "m" or "mm", times have "sec" or "msec", and so on. This is really helpful in my field -- it's not uncommon for me to open up a file that I've never looked at before and need to make modifications to it, and if the units everything things are stored in weren't immediately obvious, I'd have to go track down somebody and ask them. The annoying thing here is when people decide not to follow this standard because they think it should be obvious...
Karma: Terrifying (mostly affected by atrocities you've committed)
Now that we're talking about 'languages that invite bad coding practices'... Well, one of the best programming books I've read is 'Perl Best Practices'. Not only does it list out best practices but it tries to explain (well I might add) why you should code a certain way and why other ways aren't good to follow.
One of the habits I picked up from 'Perl Best Practices is:
instead of:
The else tends to get 'lost' when just following the closing bracket.
Why does everybody do it that way? That is, with the opening paren on the "if" line? I have always found that difficult to read. Why not
if (something)
{
stuff
}
else
{
other stuff
}
or maybe even
if (something)
{
stuff
}
else
{
other stuff
}
This last has always seemed to me to be the most readable, most obvious way to write the code. Can anyone explain why it is not used? (other than some well-known guru prefers the other?)
Teen Angel - a Ghost Story