----- Original Message ----- From: "PRADEEP GOEL" <[EMAIL PROTECTED]> To: "Paul Johnson" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Tuesday, December 03, 2002 6:27 PM Subject: Re: a Bug in PERL
> > ----- Original Message ----- > From: "Paul Johnson" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > Sent: Tuesday, December 03, 2002 5:13 PM > Subject: Re: a Bug in PERL > > I am really sorry if I am appearing offensive , I never meant to be . In perlsyn documen it does says " Don't do that " else it will get " confused" & quite below it says a C programmer does this - while same can be written in perl as this ( a shorter way ) - Now the "FACT" - you wana remove / delete the element - go the "C" way else learn foreach for shorter way - so learn both . - but it seem to be a deficiency on it's part that every such thing , which you expect as a "common sense" gets explained as a mistake in documentation - does it means only after reading the documentation line by line you should start programmimg. Or it happens , (what happens with me) you write a whole program using foreach , & after a lot of search , come to know "don't do that " & now replace that with while or for loops like in "C". is it true that more flexibility in a language => more confused the language will get > > > > >> If you look in perlsyn, under the heading "Foreach Loops", you will > > >> see: > > >> > > >> If any part of LIST is an array, C<foreach> will get very confused > > >> if you add or remove elements within the loop body, for example with > > >> C<splice>. So don't do that. > > > llllllllllllllllllll - whether C<foreach> will get confused or not , > > > but i have already, > > > since this is a common procedure , in any programming language to remove > > > /add elements > > > of an array in a loop . > > > > Yes, but not the array over which you are iterating. > $$$$$$$$$ in NO case a language changes its behaviour for an array with 1 > element > & the same code with array of 2 or more elements ( what the PERL is doing > here ) > it does pops out if last element also happens to be the only element of > array. > > > > I am unclear as to what your posted code should do. I can think of a > > number of interpretations. Perl says that this behaviour is undefined. > > This means that it doesn't need to give a (possibly arbitrary) > > interpretation and allows the implementation the flexibility to be coded > > for speed. > > > > > & also that any programming language must follow some sure mathematical > > > rules & should not get confused . > > > > The rule is "don't do that". Most languages have rules like that for > > various situations. In C, for example, a statement such as i = i++ is > > unedefined behaviour. The compiler may do what it will with that > > statement and the whole program. > > > $$$$$$$$$certainly a prog language is implemented by a compiler/interpreter > & they follow the mathematical rules , > i =i++ will too have the same behaviour for two differnt two same kind of > variales( may be arrays) > by same compiler > > BRIEF /////////////////////////////////////////// > I don't think any language defines two different behaviour anywhere at any > place for > either two arrays with different no of elements nor for any two variables of > same type > at same place,same compiler ( say continuous in a program) > That's why it seems to be a BUG > > -- > > Paul Johnson - [EMAIL PROTECTED] > > http://www.pjcj.net > > > > > > > > > > > -- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
