I am trying to take an array of hashes and based on certain values within the hash add elements of the array together and then shrink the array. Here is what I have so far: 
sub fold {

    my $self = shift;
    return if ! @{$self->{data}};

    my $array = $self->{data};
    my $date_grouped = 0;
    my $campaign_grouped = 0;
    foreach(@{$self->{groups}}) {
        $date_grouped = 1 if $_ eq 'date';
        $campaign_grouped = 1 if $_ eq 'campaign';
    }

    my $merge_index = 0;
    my $points_needed = $campaign_grouped + $date_grouped;
    @$array = sort {fold_sort($campaign_grouped,$date_grouped)} @$arra
+y;
    for(my $current_index=0; $current_index<@$array; $current_index++)
+ {
        my $el = $array->[$current_index];
        if($merge_index == $current_index) {
            next;
        }

        #compare current element to merge element
        my $match = 0;
        my $merge = $array->[$merge_index];
        $match++ if $date_grouped &&
                $el->{date} eq $merge->{date};
        $match++ if $campaign_grouped &&
                $el->{campaign_id} == $merge->{campaign_id};

        #if we can fold the array elements then do so and remove the
        #current element
        if($match == $points_needed) {
            $merge->{views} += $el->{views};
            $merge->{clicks} += $el->{clicks};
            my $del = splice(@$array,$current_index,1);
            $current_index--;
        } else {
            $merge_index++;
        }
    }

}

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Anyone have a better way of doing this? The fold_sort function just orders the array based on how were are grouping the elements. Thanks, Kenny

PS - I was not sure of what to call this so I figured "Array Folding" was a good enough term...if there is another term that people use let me know please :-)

In reply to Array Folding by BarMeister

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