while (my $line = <>) {
  chomp $line;
    
  my $tree = build_subtree($line); 
  
  print Dumper $tree->{children}[0];
  
  print Dumper $tree;
  
  walk_postorder($tree,[\&mark_heads,\&annotate]);
    
  @{$tree->{children}}[0]->{label} =~ s/^\*//; # undo top-level merge
  
  print build_subtree_oneline($tree,1), $/;
}

[download]

I did have to use both prints. They gave output below.

$VAR1 = undef;
$VAR1 = {
          'children' => []
        };

[download]

Not sure where to go from here. But would the $line input be the cause of the problem? The build_subtree($line) subroutine uses it as input.

Also, the correct link to the original script is here: https://github.com/mjpost/dptsg/blob/master/scripts/annotate_spinal_grammar.pl

In reply to Re^2: Can't use an undefined value as a HASH reference by Anonymous Monk
in thread Can't use an undefined value as a HASH reference by Anonymous Monk

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