avoid untie replacement for perl v5.18

[perl/plp/.git] / lib / PLP / Tie / Delay.pm

diff --git a/lib/PLP/Tie/Delay.pm b/lib/PLP/Tie/Delay.pm
index 0a2a0d5f58801d81c666c47dfd9684c906dac9c9..9b9b52f8f55171f2f17232f694f06e0e1eddd60c 100644 (file)
--- a/lib/PLP/Tie/Delay.pm
+++ b/lib/PLP/Tie/Delay.pm
@@ -4,7 +4,7 @@ use strict;
 no strict 'refs';
 use warnings;
 
-our $VERSION = '1.00';
+our $VERSION = '1.01';
 
 =head1 PLP::Tie::Delay
 
@@ -19,15 +19,16 @@ This module is part of the PLP internals and probably not of any use to others.
 
 sub _replace {
        my ($self) = @_;
-       untie %{ $self->[0] };
 
-       # I'd like to use *{ $self->[0] } = $self->[1]->(); here,
-       # but that causes all sorts of problems. The hash is accessible from
-       # within this sub, but not where its creation was triggered.
-       # Immediately after the triggering statement, the hash becomes available
-       # to all: even the scope where the previous access attempt failed.
-       
-       %{ $self->[0] } = %{ $self->[1]->() }
+       if ($] >= 5.018) {
+               my $code = delete $self->[1] or return;
+               $self->[0] = $code->();
+               return 1;
+       }
+
+       untie %{ $self->[0] };
+       %{ $self->[0] } = %{ $self->[1]->() };  # *{ $self->[0] } = $self->[1]->();
+       return;
 }
 
 sub TIEHASH {
@@ -67,13 +68,12 @@ sub EXISTS {
 
 sub FIRSTKEY {
        my ($self) = @_;
-       $self->_replace;
-       return 'PLPdummy';
+       $self->_replace and return 'PLPdummy';
+       return each %{$self->[0]};
 }
 
 sub NEXTKEY {
-       # Let's hope this never happens. (It's shouldn't.)
-       return undef;
+       return each %{$_[0]->[0]};
 }
 
 sub UNTIE   { }