Beefy Boxes and Bandwidth Generously Provided by pair Networks
good chemistry is complicated,
and a little bit messy -LW

Re^5: Strange Regex Behavior

by quester (Vicar)
on Dec 06, 2011 at 09:08 UTC ( #941975=note: print w/replies, xml ) Need Help??

in reply to Re^4: Strange Regex Behavior
in thread Strange Regex Behavior

Ah... yes. That would make it a bug. Sorry.

It doesn't seem to be the ternary operator causing the havoc, or pattern matching though:

$,=", "; my $i; print $i++, $i, $i++, $i, $i++, $i;


0, 3, 1, 3, 2, 3

Using Dump, we can see that the optimizer is assuming that $1 must be constant for the length of time it takes to evaluate the list:

use Data::Dump::Streamer; my $i; print Dump \($i++, $i, $i++, $i, $i++, $i);


$SCALAR1 = \do { my $v = 0 }; $SCALAR2 = \do { my $v = 3 }; $SCALAR3 = \do { my $v = 1 }; $SCALAR4 = $SCALAR2; $SCALAR5 = \do { my $v = 2 }; $SCALAR6 = $SCALAR2;

The autoincrement is also not a necessary ingredient:

use Data::Dump::Streamer; print Dump \("x"=~/(x)/, $1, "y"=~/(y)/, $1, "z"=~/(z)/, $1);


$SCALAR1 = \do { my $v = 'x' }; $SCALAR2 = \do { my $v = 'z' }; $SCALAR3 = \do { my $v = 'y' }; $SCALAR4 = $SCALAR2; $SCALAR5 = \do { my $v = 'z' }; $SCALAR6 = $SCALAR2;

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://941975]
[LanX]: fun, last time I was in Britain people had problems with my name, just rarely they said "like the children TV star Rolf Harris?", this time most replied instantly "Rolf? like the pedophile Rolf Harris" ?
LanX is perlophile
[ambrus]: Corion: read https://metacpan. org/pod/release/ MLEHMANN/AnyEvent- 7.13/lib/AnyEvent. pm#SUPPLYING-YOUR- OWN-EVENT-MODEL- INTERFACE in that case

How do I use this? | Other CB clients
Other Users?
Others romping around the Monastery: (8)
As of 2016-12-08 12:03 GMT
Find Nodes?
    Voting Booth?
    On a regular basis, I'm most likely to spy upon:

    Results (141 votes). Check out past polls.