Re: Can't use an undefined value as a HASH reference

Print out your data to see if it is really what you think it is. Part of the data structure hasn't been populated.

use Data::Dumper;

...

print Dumper $tree->{children}[0];    

# if the above produced more than "$VAR1 = {};" or "$VAR1 = undef;", p
+ost
# those results back here. If it didn't, perform the following
# and post those results

print Dumper $tree;

...

@{$tree->{children}}[0]->{label} =~ s/^\*//;
[download]

Comment on Re: Can't use an undefined value as a HASH reference Download Code

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Re^2: Can't use an undefined value as a HASH reference by Anonymous Monk on Aug 25, 2015 at 15:51 UTC
`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	[reply] [d/l] [select]
Re^3: Can't use an undefined value as a HASH reference by stevieb (Canon) on Aug 25, 2015 at 16:08 UTC
Ok, so now take a step back, and tell us what data you are sending into your script, ie. how you are calling it and with what arguments (post a example snip from the input file). We need to know what is in `$line`. I can't get to the link with the rest of the code, so I'm unsure how `build_subtree` compiles its data, and what it expects to find. Do you have another link, or can you post the full code?	[reply] [d/l] [select]
Re^4: Can't use an undefined value as a HASH reference by Anonymous Monk on Aug 25, 2015 at 16:32 UTC
Thank you'll very much for the pointers. It helped me trace through the problem. It's now resolved. I see `build_tree` was expecting a string that began with parenthesis, like so: "(TOP (S (NP (NP (NNP Pierre) (NNP Vinken))".	[reply] [d/l]
Re^4: Can't use an undefined value as a HASH reference by Anonymous Monk on Aug 25, 2015 at 16:15 UTC
The `build_subtree` subroutine has a sanity test line as follows `if ($line !~ /^$.$\s$/) { print "here: $line\n"; return undef; }` [download] And input `$line` has "1 , 4885".	[reply] [d/l] [select]