🚀 go-pugleaf

bill_winn@acm.org (Bill Winn) writes:
> In article <4gnbcp$biq@solutions.solon.com>, news@dcs.warwick.ac.uk 
> composed...
> >In code that I write, and see, every day, break is very commonly used
> >to exit a loop.  In fact, I sometimes have a break being the /only/ way
> >to exit a loop.  (Something like perl's split loop body would be a nice
> >addition to the language.)  I don't consider it to be in any way bad
> >style.
> >
> 
> I beg to differ.  break, used in the context of loops, is nothing more than 
> a glorified goto statement.  If you have conditions that force a loop to 
> stop executing why not just have a flag that is set when the loop is to 
> terminate?  Sure, you have to go to the top of the loop (in the case of for 
> and while) to test for the condition, but I would venture a guess that doing 
> such will not cause your system to fail.
> 

Here's when I use "break" to get out of the for loop.  Polite
criticism is welcome.

The problem with going back to the top of the loop to check a flag
is that the loop counter is processed before the test.  For example:

    /* returns the number that suceeded, returns MAX if failed */

    for (i = 0 ; i < MAX ; i++) {
        if (try_something(i) == SUCCESS) {
	    break;
        }
    }
    return(i);
          
Yes, I suppose that I could set a success flag, test for it in the loop,
and then conditionally decrement i before the return.  Would that really
be more clear than the break?

(I'm not arguing performance.  I agree that generally, clarity of
code is more important.)

-- 
Ken Goldman   kgold@watson.ibm.com