An alternate way of implementing import with options

An aside. Here's another way of coding it:

sub import
  {
    my $self = shift;

    my @exports = grep { "HASH" ne ref($_) } @_;
    my @options = grep { "HASH" eq ref($_) } @_;

    foreach (@options)
      {
    # handle options here
      }

    @_ = ($self, @exports);
    goto &Exporter::import;
  }
[download]

Question: will grep interfere with @_ (making the above a bit dangerous)?

Comment on An alternate way of implementing import with options Download Code

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Re: An alternate way of implementing import with options by japhy (Canon) on Feb 13, 2001 at 21:32 UTC
`grep()` won't do anything bad to `@_`, but I am personally against doing two operations in a row like you did that are complements. That being said, I'd rewrite the `@_`-filtering line as: `my %args; push @{ $args{ref($_) eq 'HASH' ? 'opt' : 'ext'} }, $_ for @_;` [download] Or, I might even do a moving-`splice()` trick: `sub import { my $self = shift; my ($i,$j,@options); for (@_) { if (++$j, ref($_) eq 'HASH') { push @options, splice(@_, $j + --$i, 1); $_ = $_[$j+$i], redo if $j + $i < @_; } } # handle @options # @_ now only holds elements which aren't hash refs $self->SUPER::import(@_); }` [download] </code> `japhy` -- Perl and Regex Hacker	[reply] [d/l] [select]
Re (tilly) 2: An alternate way of implementing import with options by tilly (Archbishop) on Feb 13, 2001 at 21:43 UTC
That fails. The point of the goto in the original is that Exporter checks caller to figure out what package to export symbols to. You have to use export_to_level() instead, and my experience suggests that that function is more likely to cause warning messages to come from the wrong place than I like. (Also with 5.6+ it will force you to load Exporter::Heavy which is slower. If that matters to you.) Aside from that, I don't like using explicit indexes if I can avoid it...	[reply]
Re: Re (tilly) 2: An alternate way of implementing import with options by japhy (Canon) on Feb 13, 2001 at 21:46 UTC
Oh, d'oh, right. I knew there was some reason I knew `goto` was being used. So yeah, modify my code as needed. Silly jeffy. `japhy` -- Perl and Regex Hacker	[reply]
Re: An alternate way of implementing import with options by merlyn (Sage) on Feb 13, 2001 at 21:28 UTC
Those duplicate greps bug me a bit. How about: `for (@_) { if (ref($_) eq "HASH") { push @options, $_; } else { push @exports, $_; } }` [download] -- Randal L. Schwartz, Perl hacker	[reply] [d/l]
Back where we started by tilly (Archbishop) on Feb 13, 2001 at 21:48 UTC
That is morally the same as my original version. In fact before I posted I had thought about having 2 arrays, and then I thought that instead of tracking options, it probably made more sense to process in place. :-)	[reply]


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