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Postings from September 2013
On Sun Sep 29 13:24:28 2013, plokinom@gmail.com wrote:
> But regarding library code: If your library code blindly modifies global
> variables (such as $_), it's probably broken.
---
It didn't "blindly modify" it. The value of $_ was *saved*
in the code that made use of it and restored when done.
That would *seem* to be a perfectly reasonable solution in most
languages. Even in assembler, if you use registers, you save them,
you use them, you restore them.
Asking for that ability in perl.
if I have:
sub reader() {
my save=$_";
open(my $fh, "<myfile") or die "open:$!";
while (<$fh>) {
...
}
$_=$save;
}
that saves $_ and restores it upon exit -- it will still
fail if, in the callstack above "somewhere", that called this --
it was called from a
for ('a' 'b' 'c') {
...reader()
}
reader will fail with an error claim it attempted to modify
a read-only var.
The library function cannot use while(<>) while "$_" is read
only -- despite the fact that it was trying to be "good" and
saved $_ before using it (and restored it upon exit).
That is the issue.
---
via perlbug: queue: perl5 status: rejected
https://rt.perl.org:443/rt3/Ticket/Display.html?id=120047
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