diff options
Diffstat (limited to 'lib/Tie/Hash.pm')
| -rw-r--r-- | lib/Tie/Hash.pm | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/lib/Tie/Hash.pm b/lib/Tie/Hash.pm index 65f9dd0b38..6f8c34fdfb 100644 --- a/lib/Tie/Hash.pm +++ b/lib/Tie/Hash.pm @@ -105,6 +105,13 @@ Delete the key I<key> from the tied hash I<this>. Clear all values from the tied hash I<this>. +=item SCALAR this + +Returns what evaluating the hash in scalar context yields. + +B<Tie::Hash> does not implement this method (but B<Tie::StdHash> +and B<Tie::ExtraHash> do). + =back =head1 Inheriting from B<Tie::StdHash> @@ -131,7 +138,7 @@ should operate on the hash referenced by the first argument: =head1 Inheriting from B<Tie::ExtraHash> The accessor methods assume that the actual storage for the data in the tied -hash is in the hash referenced by C<(tied(%tiedhash))[0]>. Thus overwritten +hash is in the hash referenced by C<(tied(%tiedhash))-E<gt>[0]>. Thus overwritten C<TIEHASH> method should return an array reference with the first element being a hash reference, and the remaining methods should operate on the hash C<< %{ $_[0]->[0] } >>: @@ -156,15 +163,18 @@ same storage algorithm as in TIEHASH subroutine above. Hence, a typical package inheriting from B<Tie::ExtraHash> does not need to overwrite this method. -=head1 C<UNTIE> and C<DESTROY> +=head1 C<SCALAR>, C<UNTIE> and C<DESTROY> The methods C<UNTIE> and C<DESTROY> are not defined in B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>. Tied hashes do not require presense of these methods, but if defined, the methods will be called in proper time, see L<perltie>. +C<SCALAR> is only defined in B<Tie::StdHash> and B<Tie::ExtraHash>. + If needed, these methods should be defined by the package inheriting from -B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>. +B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>. See L<pertie/"SCALAR"> +to find out what happens when C<SCALAR> does not exist. =head1 MORE INFORMATION @@ -230,6 +240,7 @@ sub NEXTKEY { each %{$_[0]} } sub EXISTS { exists $_[0]->{$_[1]} } sub DELETE { delete $_[0]->{$_[1]} } sub CLEAR { %{$_[0]} = () } +sub SCALAR { scalar %{$_[0]} } package Tie::ExtraHash; @@ -241,5 +252,6 @@ sub NEXTKEY { each %{$_[0][0]} } sub EXISTS { exists $_[0][0]->{$_[1]} } sub DELETE { delete $_[0][0]->{$_[1]} } sub CLEAR { %{$_[0][0]} = () } +sub SCALAR { scalar %{$_[0][0]} } 1; |