blazar has asked for the wisdom of the Perl Monks concerning the following question:

Update: solved! Well, it will be solved...

I was playing around with tie and interpolation (for obfu purposes, FWIM), and I got what seems to me as a strange result:

#!/usr/bin/perl -l use strict; use warnings; sub TIESCALAR { bless \my $i, shift } sub FETCH { ${shift,}++ } tie my $s, 'main'; print "$s$s$s"; print "$s$s$s"; tie my $t, 'main'; print " $t$t$t"; print " $t$t$t"; __END__

This gives me the following output:

112 445 012 345
so it seems that something wrong, or at least unexpected, happens when a tied variable appears at the beginning of an interpolating string.

Remark: please note that this is not an artifact of the minimalistic nature of the example, i.e. of the fact that I use main as the class providing the implementation of the variable, and that I do not provide a STORE method. I tried with more complex stuff and indeed the behaviour shown above persists.

Also note that with arrays everything works as one would naively expect - consider:

#!/usr/bin/perl -l use strict; use warnings; sub TIEARRAY { bless \my $i, shift } sub FETCHSIZE { 3 } sub FETCH { ${shift,}++ } tie my @s, 'main'; print "@s - @s - @s"; __END__
which gives me:
0 1 2 - 3 4 5 - 6 7 8