diff options
Diffstat (limited to 'pod/perltie.pod')
| -rw-r--r-- | pod/perltie.pod | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/pod/perltie.pod b/pod/perltie.pod index c6eb7156ce..79a749e68a 100644 --- a/pod/perltie.pod +++ b/pod/perltie.pod @@ -180,17 +180,26 @@ TIESCALAR classes are certainly possible. =head2 Tying Arrays A class implementing a tied ordinary array should define the following -methods: TIEARRAY, FETCH, STORE, and perhaps DESTROY. +methods: TIEARRAY, FETCH, STORE, FETCHSIZE, STORESIZE and perhaps DESTROY. -B<WARNING>: Tied arrays are I<incomplete>. They are also distinctly lacking -something for the C<$#ARRAY> access (which is hard, as it's an lvalue), as -well as the other obvious array functions, like push(), pop(), shift(), -unshift(), and splice(). +FETCHSIZE and STORESIZE are used to provide C<$#array> and +equivalent C<scalar(@array)> access. + +The methods POP, PUSH, SHIFT, UNSHIFT, SPLICE are required if the perl +operator with the corresponding (but lowercase) name is to operate on the +tied array. The B<Tie::Array> class can be used as a base class to implement +these in terms of the basic five methods above. + +In addition EXTEND will be called when perl would have pre-extended +allocation in a real array. + +This means that tied arrays are now I<complete>. The example below needs +upgrading to illustrate this. (The documentation in B<Tie::Array> is more +complete.) For this discussion, we'll implement an array whose indices are fixed at its creation. If you try to access anything beyond those bounds, you'll -take an exception. (Well, if you access an individual element; an -aggregate assignment would be missed.) For example: +take an exception. For example: require Bounded_Array; tie @ary, 'Bounded_Array', 2; |