Merging Hash
Cyber jacked ya, eh?
Merge Hash
sub merge_hash {
my ($self, $precedent, $subordinate) = @_;
my @not = grep !exists $precedent->{$_}, keys %{$subordinate};
@{$precedent}{@not} = @{$subordinate}{@not};
return $precedent;
}
I blog about Perl.
I'm not sure I get it.
nevermind, got it. Can't call it as a method ($self) when used as a function. Oops. Anyway if you prototype as (\%\%) as a function then you can call it on two hashes. Or just ignore me. Thats probably best.
I am not sure that i uderstand your idea...
merge_hash takes \%precedent by reference and it gets changed + returned. Overkill?
As i know, the best way to merge hashes is:
my %merged = %precedent, %subordinate;
Pardon the noise. This was mostly a test (with a does of sarcasm). I figured it needed at least some piece of code, and so I grabbed the closet snippet around.
Yeah something like
my %merged = (%subordinate, %precedent);would have the same effect, thanks.
Rest assured, my next post will be a little more entertaining.
I never like calling this a merge because some stuff gets left out or overwritten. I think a merge should promote values to array references with both values for shared keys. We should come up with some other term for this, like update.
Most often I use this to set defaults, then overlay that with specified answers. The new layer hides anything in common, which is the point.
It was hard to get whether it's a joke or an invention :))
@brian: collide? :) Anyway, I think sometimes merge does overwrite/leave out data, particularly conflicting ones.