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Re^5: initialize all values in a hash

by DrHyde (Prior)
on May 18, 2012 at 15:35 UTC ( #971331=note: print w/replies, xml ) Need Help??

in reply to Re^4: initialize all values in a hash
in thread initialize all values in a hash

I mostly use Tie::Hash::Vivify to prevent autovivification thus:
my $hashref = Tie::Hash::Vivify->new( sub { confess("No auto-vivifying!\n".Dumper(\@_)) } )
to avoid those annoyingly hard-to-track-down bugs where you've typoed a hash key.

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Re^6: initialize all values in a hash
by tobyink (Abbot) on May 18, 2012 at 16:49 UTC

    The autovivification module is pretty good for this kind of thing. Offers you the ability to simply switch off autovivification, warn about it, or croak. Rather than being tied to a particular hash, it's lexically scoped. And it's context-sensitive, so you could decide that 'store' operations are allowed to autovivify, like:

    { no autovivification qw(strict); use autovivification qw(store); my %hash; $hash{foo}{bar}{baz} = 1; # autovivifies OK delete $hash{fool}{bar}{baz}; # dies }

    If only autovivification weren't so tricky to type.

    perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

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[ambrus]: I don't much like highlighting matching parenthesis, because I've had some bad experiences with distracting implementations of that.

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