Hello honorable Monks,
Today I uncovered a very subtle bug in one of my programs, and although I fixed it I have no idea what is actually going on. Here is an example program that demonstrates what happens:
#!/usr/bin/perl
my $test = 'abc , def';
for my $sub qw/trim_start trim_end trim_start trim_end/ {
$test =~ /([\s\w]+),([\s\w]+)/;
$sub->($1, $2);
}
sub trim_start {
while (@_) {
my $string = shift @_;
$string =~ s/\A\s+//ms;
print "$string\n";
}
}
sub trim_end {
while (@_) {
my $string = shift @_;
$string =~ s/\s+\z//ms;
print "$string\n";
}
}
What is the difference between the two regexes? Why does only trim_end() destroy $2? I solved my problem by doing:
my @args = @_;
while (@args)...
but I still would like to know what causes this.
Thank you in advance.
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