A Stack of Moose: Perl Challenge 95 addendum
I have already solved and blogged Challenge 95, and added:
If I go ahead and Moose this solution, I’ll make another blog post.
And wouldn’t you know, I got around to it. I have never done much with Moose and haven’t fully put it into my head. I think that the big deal is that I write has 'stack' => ( is => 'rw', isa => 'ArrayRef',) instead of sub new { ... }, so that whatever is in new() gets handled. There’s also case handling. In this case, we say isa => 'ArrayRef' but could’ve written isa => 'ArrayRef[Int]' to specify that theis will be a stack of integers, or 'ArrayRef[Num]' to allow floating-point numbers as well. In the Challenge, we know it’ll just be ints, but in places where I don’t have total control over what everyone else is trying, types make more and more sense.
Which puts me a decade or two behind the rest of the Perl community, perhaps? You know the parts of the language you use, and it never was something I felt encouraged to bolt onto our legacy code mess where I worked the most, so I don’t feel bad about it.
Otherwise, there’s a lot that looks identical to the non-Moose version I posted previously. List::Util::min to avoid crossover with Stack::min. return pop $self->{values}->@*.
package Stack;
use strict;
use warnings;
use feature qw{ say signatures state };
use Moose;
use List::Util;
has 'stack' => (
is => 'rw',
isa => 'ArrayRef',
);
sub all {
my $self = shift;
say join " ", ' --', $self->{stack}->@*
if defined $self->{stack}[-1];
}
sub push {
my $self = shift;
my $val = shift;
push $self->{stack}->@*, $val;
}
sub top {
my $self = shift;
return defined $self->{stack}[-1] ? $self->{stack}[-1] : undef;
}
sub min {
my $self = shift;
return List::Util::min $self->{stack}->@*;
}
sub pop {
my $self = shift;
return defined $self->{stack}[-1]
? pop $self->{stack}->@*
: '';
return pop $self->{stack}->@*;
}
# I am told this is necessary to keep Moose overhead low. I suppose that means this cuts off the antlers?
no Moose;
__PACKAGE__->meta->make_immutable;
I’ve heard that Moo is a smaller Moose, so I tried cutting the se and running it, and there’s a problem with the ArrayRef, which I didn’t care enough to hunt down.
I guess, right now I’m somewhere between “there’s not enough difference here move from what I already do” and “there’s enough new hotness here that I need to get it into my head”, and finding it a lot easier to search "perl" "moose" "*keyword*" than to dig through MetaCPAN for the answers to the questiosn I come up with.
Anyway, this is the promised MOose solution.