NAME

Class::AutoDB::Collection - Compare two collection definitions and maintain differences

SYNOPSIS

This is a helper class for Class::AutoDB::Registry to to process differences between in-memory and saved registries

 use Class::AutoDB::CollectionDiff;
 use Class::AutoDB::Collection;
 my $diff=new Class::AutoDB::CollectionDiff
   (-baseline=>$saved, -change=>$in_memory);
 if ($diff->is_sub) {               # is new collection subset of saved one?
   $registry=$saved_registry;       # if so, use saved one
 } elsif  ($diff->is_different) {   # else get changes
   my %new_keys=$diff->new_keys;    # 
   my @expanded_collections=$diff->expanded_collections;
 } else {
   die “New collection inconsistent with old”;
 }

DESCRIPTION

This class compares two collection definitions and records their differences. The first collection is considered the baseline, and differences are reported relative to it. This class does not talk to the database.