Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw

Re: array => hash of occurrence indexes

by kcott (Chancellor)
on Sep 12, 2013 at 05:19 UTC ( #1053646=note: print w/replies, xml ) Need Help??

in reply to array => hash of occurrence indexes

G'day pldanutz,

I generally think it's better to pass around scalars than entire data structures, so returning a reference to that hash would be my preference.

If you wrapped $h{$k} in @{...}, you could dispense with if (! $h {$k}) { $h {$k} = [] } entirely.

Even if you're using 5.012 for other reasons elsewhere in your code, I see little, if any, value in using each here. It's easy to write it for any Perl5.

Putting all that together, you could code occurrences() like this instead:

sub occurences { my %h; my $i = 0; push @{$h{$_}}, $i++ for @_; return \%h; }

If you were looking for a golf answer, you could start with the following and then proceed to remove whitespace until illegibility was achieved. :-)

sub occurences { my ($i, %h) = 0; push @{$h{$_}}, $i++ for @_; \%h }

Here's my tests:

-- Ken

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1053646]
and all is quiet...

How do I use this? | Other CB clients
Other Users?
Others cooling their heels in the Monastery: (2)
As of 2017-09-22 04:28 GMT
Find Nodes?
    Voting Booth?
    During the recent solar eclipse, I:

    Results (257 votes). Check out past polls.