On Tue, 2004-07-27 at 12:54, Daniel Allen wrote:
> LINE: while (defined($_ = )) {
> /(\d+)/;
> print "$1 ";
> }
> continue {
> #print $_;
> }
The continue interposes another block into the loop. According to
perlre as quoted by Steve below, $1 et al. are scoped until the end of
the
OK, here is the answer:
http://www.perldoc.com/perl5.6.1/pod/perlre.html says:
The numbered variables ($1, $2, $3, etc.) and the related punctuation
set ($+, $&, $`, and $') are all dynamically scoped until the end of the
enclosing block or until the next successful match, whichever comes
first.
Tolkin, Steve said:
> What is the scope of $1 and when does it get reset?
here's a start:
http://www.greglondon.com/iperl/html/iperl.html#20_5_2_Capturing_parentheses_not_capturing
I suppose I should make a note to include some s/// examples...
note to self: self, add some s/// examples.
--
Ron Newman said:
>>If I intend to write something like
>>s/([ab])c/$1c/;
> That's not possible in general, because there could legitimately be a $1 left
> over from a previous regex match.
the /$1c/ will only get hit if the /([ab])c/ part matches,
so if a substitution occurs, $1 will always be
Summary:
What is the scope of $1 and when does it get reset?
Details:
Thanks for the reply, Ron.
It indicates that I understand this even less than I thought.
What are the rules for "remembering" a previous value of $1
(and the other numeric variables set by pattern matching)?
In the program
>If I intend to write something like
>s/([ab])c/$1c/;
>but accidentally omit the parentheses and write
>s/[ab]c/$1c/;
>I get a run time error message -- assuming
>the pattern matches the input data.
>But if the test data does not expose
>this bug I might not find out about it until later.
>
>Is
If I intend to write something like
s/([ab])c/$1c/;
but accidentally omit the parentheses and write
s/[ab]c/$1c/;
I get a run time error message -- assuming
the pattern matches the input data.
But if the test data does not expose
this bug I might not find out about it until later.
Is there any
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