ID: 29287
Comment by: jdemaris at cse dot unl dot edu
Reported By: abodeman at yahoo dot com
Status: Open
Bug Type: Feature/Change Request
Operating System: Irrelevant
PHP Version: Irrelevant
New Comment:
What is still likely to be added? Labels? Gotos? Both?
Many developers, myself included, would welcome both features. I'm
curious why you were so quick to spout an unqualified "no" to the
original post.
Previous Comments:
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[2004-08-02 11:42:23] [EMAIL PROTECTED]
It's still likely to be added ;-)
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[2004-07-26 19:44:54] jhelzer at cse dot unl dot edu
Whether this is the relevant place or not, to treat goto and labels as
two heads of the same body (as you seem to imply) is silly. I can
understand a reluctance to implement goto, but adding labels for the
break statement make a tremendous amount of sense.
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[2004-07-21 00:00:59] jhelzer at cse dot unl dot edu
I am curious, why not?
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[2004-07-20 22:31:59] [EMAIL PROTECTED]
We won't implement goto and or labels.
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[2004-07-20 21:58:09] abodeman at yahoo dot com
Description:
------------
As I have outlined in the PHP manual in user comments under "break",
the "break n" syntax is obnoxious. Code containing a "break n" can
silently become broken if it is surrounded by another loop; I believe
it is the only language feature that will break this way. It is also
difficult to figure out where control resumes after a "break n"; you
have to count loops and switch statements, but ignore if statements.
With this in mind, I propose a much better syntax, one that has been
time-tested and proven to work well in other languages: line labels. By
adding line labels to PHP, you can say "break label;" and break out of
the loop or switch statement labeled as "label". Putting more loops in
the code won't break anything, and it is easier to determine where
control will resume.
While you're at it, a "goto" statement would also be very much
appreciated in PHP. Yes, I know, the vast majority of programmers are
yelling at me now, because they have been inundated by books and
teachers telling them that goto is always 100% evil. The truth of the
matter is that goto is sometimes the natural way to do things. Sure,
it's possible to write code without goto, but it's also possible to
write code without switch statements or for loops. And eliminating goto
from a language does not automatically make well-written code.
Consider the following scenario: There is an if statement inside a for
loop inside a switch statement inside two while loops. The situation is
not uncommon. Now, inside this if statement are some 60 lines of code.
The fifth line of code is some test; if the test fails, execution
should jump just past the end of the if statement, inside the for loop.
Currently the only way to do that is to wrap the remaining 55 lines of
code inside yet *another* if statement, adding yet *another* level of
indenting. Ick.
Obviously the natural solution here is to have a goto statement that
jumps to where it needs to go. But PHP doesn't have anything that will
work. There's not even a good kludge for it. If you didn't want to wrap
the 55 lines in an if statement, you could wrap the 60 lines in a do {
... } while (0); and just use a break, but that's even worse.
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Edit this bug report at http://bugs.php.net/?id=29287&edit=1
