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Posted By

noah on 07/03/07


Tagged

table object default pattern compare hash 2001 lookup


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provide default values for a hash

Published in: Perl 

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  1. ################
  2. #COMPARE_N_SUBSTITUTE
  3. #Compare a hash to a fall-through hash.  If any values are present in the fall-through and not in the current values then insert them in the DYC hash.
  4. #compare_n_substitute(hash1, hash2)  #insert key-value-pairs from hash2 into hash1 only if those pairs are not defined in hash1.
  5. #compare_n_substitute(\%hash, \%default)
  6. sub compare_n_substitute(\%\%) {
  7.     my ($hashref, $fallthrough_hashref) = @_;
  8.     for my $key (keys %$fallthrough_hashref) {
  9. 	unless (defined($$hashref{$key})) {
  10. 	    $$hashref{$key} = $$fallthrough_hashref{$key};
  11. 	}
  12.     }
  13. }

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