Here are a couple more alternatives... 
sub ReadSource{
    my ($DataSource, $HashRef) = @_;
    my @Data = get_data();
    for (@Data){
      my $item = $HashRef->{$_} ||= [];
      push( @$item, $DataSource );
    }
}

[download]
..or.. 
sub ReadSource{
    my ($DataSource, $HashRef) = @_;
    my @Data = get_data();
    push( @{ $HashRef->{$_} ||= [] }, $DataSource )
     for @Data;
}

[download]
There really is more than one way to do it!

In reply to Re: Complex Data Structure Suggestions Wanted by djohnston
in thread Complex Data Structure Suggestions Wanted by Ninthwave

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