SurturZ's Journal: In defense of GOTO

I'm amazed at how religious some programmers are about not using the GOTO statement.

I was reading this (quite interesting, actually) article and noticed the author claim the following:

Once you realize this, you also realize that all those objections to the banning of the goto go away--there really is no place for it in well-written code. This may sound like an extreme viewpoint, but speaking as an experienced programmer, the only times I can recall needing a goto in the last 20 years were when using languages that didn't support adequate control constructs (most of which, thankfully, are extinct now). I have never written a goto in C code.

The author later details a piece of code that includes the C equivalent of a

Do
    If Something Then Exit Do
    If SomethingElse Then Exit Do
    etc ...
Loop While False

and then says this about it:

The second interesting feature of the above example routine is the do-once construct. This conforms to the rule for structures which nest: you enter it at the top, and exit it at the bottom. It allows for a linear sequence of any number of steps, any of which can fail, in which all prior steps must have succeeded in order for a given step to be processed.

Oddly, some people who see this construct for the first time tend to react unfavourably. It is a loop construct which is not being used for looping, and a few people don't like that. What can I say? It is a deficiency of the C language that it doesn't offer a construct specifically for this purpose, so reusing the do-construct (and carefully marking it as such right from the beginning, with the /*once*/ comment) is the best I can do. I need a structure for this purpose, and the alternatives that have been suggested to me are even worse. Deal with it!

I hate to break it to you dude, but there IS a structure, and it is called GOTO. A couple of line labels and you would be golden:

SeriesOfChecks:
    If Something Then GOTO SeriesOfChecksExit
    If SomethingElse Then GOTO SeriesOfChecksExit
    etc...
SeriesOfChecksExit:

I believe there is still a place for GOTO in modern programming. The main case where GOTO is useful is a situation as follows:

• You have a transaction consisting of multiple steps
• If any step fails, the transaction as a whole fails, and you do not need to perform the subsequent steps
• Whether or not the transaction fails, some cleanup operations are required

A common example is parsing a file that might be corrupt or in the wrong format.

My belief is that GOTO is a fundamental building block of a programming language. You can replace a lot of structures (e.g. Sub, Function, Do...Loop) with GOTO, but you can't do the reverse.

Sparingly and properly used, GOTO can simplify code and improve readability.