Re: Tied array to track last-accessed element

My only comment is to purvey the methods as functions, which is what I do in most of my tie-related modules:

package Tie::Array::LastIndex;

# ...

use Carp 'croak';
use Exporter;
@EXPORT = qw( which what );

# ...

sub which (\@) {
  my $aref = shift;
  my $obj = tied @$aref;
  croak "which() only accepts arrays tied to " . __PACKAGE__
    unless $obj and $obj->isa(__PACKAGE__);
  return $obj->{INDEX};
}

sub what (\@) {
  my $aref = shift;
  my $obj = tied @$aref;
  croak "what() only accepts arrays tied to " . __PACKAGE__
    unless $obj and $obj->isa(__PACKAGE__);
  return $obj->{ARRAY}[ $obj->{INDEX} ];
}
[download]

Like so.

_____________________________________________________
Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

Comment on Re: Tied array to track last-accessed element Download Code

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Re^2: Tied array to track last-accessed element by davido (Cardinal) on Sep 23, 2004 at 21:53 UTC
The way you've got them set up, `which()` and `what()` can only be used as functions, not as methods, right? I have mixed feelings on the suggestion. I'll express what I see as the pros and cons, and maybe you can let me know what I'm leaving out. Pros to exporting functions for this tied array class: Simpler interface -- Doesn't require Object Oriented understanding. Faster -- Object oriented solutions have extra overhead (but a tied array is an object anyway, and the functional which() and what() do even more extra work in discovering the object of the tie). Pros to using the OO interface: which() and what() are not exactly uncommon words. Reserving them as object methods keeps them from mucking up global namespace. which() and what(), as names, make more sense to me when they're directed to a tied object, than to an array reference. `$tied_array->which()` means more to me than `which(@array)`, because it tells me (the casual reader) that which() is a method of this class, rather than just some exported funtion from who-know-which package. But I am not necessarily seeing the whole picture, and I value your opinion, so please do let me know what arguments would best support exporting which() and what() as functions. ...If I were to go ahead an implement that suggestion, I might export them with more explicit names, such as `which_index()` and `what_value()`... or some-such. I like your use of Carp croak(). I'll look at working that into the code in the meantime. Dave	[reply] [d/l] [select]
Re^3: Tied array to track last-accessed element by japhy (Canon) on Sep 24, 2004 at 05:14 UTC
The main reason I create functions instead of methods for my tied data types is because tying variables is supposed to be a transparent act, and calling a function with that array should be just as transparent. _____________________________________________________ Jeff `japhy` Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and `perl` hacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart	[reply]