On Jan 10, 2013, at 7:33 PM, budi pearl wrote:
> Hi All,
>
> I would like to pass hash: %{$routes{"ROUTE-252"}} instead of %routes but
> got this error:
>
> [budi@dev bin]$ ./print_path.pl
> Type of arg 1 to each must be hash (not hash element) at
> ./print_path.plline 38, near "}) "
> Execution of ./print_path.pl aborted due to compilation errors.
>
> ----
> #use strict;
If you had not commented out this line, Perl would have told you what the
problem is.
> use Graph::Directed;
> use Data::Dumper;
>
> my %routes = (
> "ROUTE-252" => {
> # src => dest
> CX77 => "ABEP",
> ABEP => 441,
> 441 => 427,
> 427 => 444,
> 444 => "MGWQ",
> MGWQ => "CDEF"
> },
>
> "ROUTE-432" => {
> AAA => "BBB",
> BBB => "CCC",
> CCC => "DDD",
> DDD => "EEE",
> EEE => "FFF",
> XXX => "YYY",
> YYY => "ZZZ",
> }
> );
>
> my $id = "ROUTE-252";
> print Dumper $routes{$id};
>
> print_path($id, \%{$routes{$id}});
You are passing a reference to the inner hash, but you are doing it by first
de-referencing, then referencing the inner hash. This can be simply:
print_path( $id, $routes{$id} );
>
> sub print_path {
> my ($label, $edges) = @_;
You are storing the hash reference in the scalar variable $edges. This value is
$routes{'ROUTE-252'}.
> my $graph = Graph::Directed->new;
>
> while (my ($start, $end) = each $edges{$label}) {
There are two problems here:
1. $edges{$label} is a member of the hash %edges, but you have not declared or
defined %edges in your subroutine.
2. You are trying to access the member $route{'ROUTE-252'}->{'ROUTE-252'}. In
other words, you are indexing twice. You should either pass the top-level hash
and index in the subroutine, or pass the indexed hash member and do not index
in the subroutine:
print_path( $id, \%routes );
...
sub print_path
{
...
while( my ($start, $end) = each %{$edges->{$label}} ) {
OR
print_path( $id, $routes->{$id} );
...
sub print_path
{
...
while( my ($start, $end) = each %$edges ) {
> #while (my ($start, $end) = each %{$routes{$label}}) {
> $graph->add_edge($start, $end);
> }
>
> my @sinks = $graph->sink_vertices;
> for my $source ($graph->source_vertices) {
> for my $sink (grep $graph->is_sink_vertex($_),
> $graph->all_successors($source)) {
> print "$label: ", join ' - ', $graph->path_vertices($source,
> $sink);
> print "\n";
> }
> }
>
>
> }
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