Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
      My perl program frequently needs to retrieve a cached set of data that is indexed by a positive but sparsely populated set of integers.

By the way it's Perl. Lower case perl is the command. Oh... never mind.

Based on what you said I'd go with a hash. If you really want to implement a sparse array you could to this:

package IndexedSparseArry; sub new { shift; my $self={ array => [ ] }; bless $self,"IndexedSparseArray"; } sub insert { my ($self,$index,$data)=@_; my @work = @{$self->{array}}; if ( $#work == -1 ) { # Nothing there yet. push @work,{index => $index, data => $data}; } else { my $i=0; # not to be confused with index. while ( ($i < $#work) && ($work[$i]->{index} < $index)){ $i++ } if ( $i == $#work ) { if ($work[$1] < $index ) { push @work,{index => index, data => $data); } else { $work[$i+1]=$work[$i]; $work[$i] = { index => $index, data=>$data}; } } else { my $j = $#work + 1; while ($j > $i){ $work[$j] = $work[$j-1]; $j--; } $work[$i] = { index => $index, data => $data }; $self->{array} = [@work]; } 1;
Save that file to and in your main program:
use strict; use warnings; use IndexedSparseArray; my $repo = IndexedSparseArray->new(); while (<i am reading in data >){ | handwaving $repo->insert($index,$data); } | etc.
Big Caveat: I didn't test this and I was interrupted a bunch of times. This should work, but...

I think I've given you something to chew on, hope it helps.

Peter L. Berghold -- Unix Professional
Peter -at- Berghold -dot- Net; AOL IM redcowdawg Yahoo IM: blue_cowdawg

In reply to Re: Array vs. Hash for sparsely integer-indexed data by blue_cowdawg
in thread Array vs. Hash for sparsely integer-indexed data by puterboy

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the radiator hisses contentedly...

    How do I use this? | Other CB clients
    Other Users?
    Others drinking their drinks and smoking their pipes about the Monastery: (5)
    As of 2018-03-21 05:35 GMT
    Find Nodes?
      Voting Booth?
      When I think of a mole I think of:

      Results (263 votes). Check out past polls.