GOTO's and LABELS?!?!
Yeah, what about them? People easily balk at seeing a goto,
but not all goto's are evil. There are two famous papers on the
subject, Go To considered harmful, by E. Dijkstra (although
it was C. Hoare that give the paper a title), but that paper doesn't
say one should never use a goto - it warns for improper
use. And then there's of course Structured Programming with Goto.
By D. E. Knuth - perhaps the best Computer Scientist that ever lived.
Besides, aren't we all fond of next, last
and redo? They are nothing but gloried gotos.
Abigail
| [reply]
[d/l]
[select] |
Having coded in systems that don't have good looping constructs, I'd have to say that GOTO's are sometimes a necessary evil. In this script, I'm sure there was a better way than a Goto, but we didn't have enough code to tell. I try and avoid Goto's unless I'm programming on my TI-86, at which point they can be quite handy.
However, Labels can be quite handy in Perl. A good example might be if you were iterating through an AOA simulating a matrix and wanted to find an element equal to 5 by using two nested loops. You could use a label to break out from the inner loop all the way out of the outer loop quite easily. If for some reason you have to have a loop in a loop in a loop in a loop in a loop but need a mechanism to break out of all of them at once, a label is the easiest way to do it. Labels can also add to the readability of code if you understand how they work.
All tools have their place - goto is one of those tools that should be used carefully because it can easily create an infinite loop that isn't nearly as easy to some other infinite loops.
~Brian | [reply] |
