Re: iterators: traversing arbitrary data structure

Update: OOPS! The solution in this post will show you all the values, but will not allow you to change them. See my reply to this post for a more appropriate solution.

Well, you could do

my $iter = get_value_iter($oWkBook);
while ($iter->(my $item)) {
   print("$item\n");
}
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if you defined get_value_iter as follows:

sub get_value_iter {
   my @values = @_;
   my $sub_iter;

   return sub {
      our $rv; local *rv = \$_[0];

      for (;;) {
         if ($sub_iter) {
            if ($sub_iter->($rv)) {
               return 1;
            }

            undef $sub_iter;
         }

         return if not @values;

         $rv = shift(@values);

         while (ref($rv) eq 'SCALAR') {
            $rv = $$rv;
         }

         if (ref($rv) eq 'ARRAY') {
            $sub_iter = get_value_iter(@$rv);
            next;
         }

         if (ref($rv) eq 'HASH') {
            $sub_iter = get_value_iter(values %$rv);
            next;
         }

         return 1;
      }
   };
}
[download]

Scalar::Util's reftype can be used instead of ref if you wish to traverse objects.

Comment on Re: iterators: traversing arbitrary data structure Select or Download Code

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Re^2: iterators: traversing arbitrary data structure
by ikegami (Patriarch) on Jan 11, 2006 at 21:48 UTC

You could do

my $iter = get_value_iter($oWkBook);
while ($iter->(my $item_ref)) {
   $$item_ref =~ s/^\s+\n$//;
}
[download]

get_value_iter

sub get_value_iter {
   our $val; local *val = \$_[0];

   if (ref($val) eq 'SCALAR') {
      my $ref = $val;
      return sub {
         my $sub_iter = get_value_iter($$ref);
         return $sub_iter->($_[0]);
      };
   }

   if (ref($val) eq 'ARRAY') {
      my $ref = $val;
      my $key = 0;
      my $sub_iter;
      return sub {
         for (;;) {
            return 1 if $sub_iter && $sub_iter->($_[0]);
            return if $key >= @$ref;
            $sub_iter = get_value_iter($ref->[$key++]);
         }
      };
   }

   if (ref($val) eq 'HASH') {
      my $ref = $val;
      my @keys = keys %$ref;
      my $sub_iter;
      return sub {
         for (;;) {
            return 1 if $sub_iter && $sub_iter->($_[0]);
            return if not @keys;
            $sub_iter = get_value_iter($ref->{shift @keys});
         }
      };
   }

   {
      my $ref = \$val;
      my $done = 0;
      return sub {
         return if $done;
         $_[0] = $ref;
         $done = 1;
         return 1;
      };
   }
}
[download]

Scalar::Util's reftype can be used instead of ref if you wish to traverse objects.

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