File Coverage

blib/lib/Math/SimpleVariable.pm

Criterion	Covered	Total	%
statement	41	42	97.6
branch	7	8	87.5
condition	3	6	50.0
subroutine	12	12	100.0
pod	5	8	62.5
total	68	76	89.4

package Math::SimpleVariable;

require 5.005_62;
use strict;
use warnings;
use Carp;

our $VERSION = '0.03';
use fields (
   'name',  # a string with the name of the variable
   'value', # the numerical value of the variable
);

sub new {
    # parse the arguments
    my $proto = shift;
    my $pkg = ref($proto) || $proto;
    my %arg = ();
    if(@_ == 1 && defined(ref $_[0])) {
	if(ref($_[0])->isa('Math::SimpleVariable')) {
	    # new() was invoked as a copy ctor
	    return $_[0]->clone();
	}
	elsif(ref($_[0]) eq 'HASH') {
	    # the arguments are passed in a ref to a hash
	    %arg = %{$_[0]};
	}
	else {
	    croak "Invalid argument passed to Math::SimpleVariable::new()";
	}
    }
    else {
	%arg = @_;
    }

    # build the object
    my Math::SimpleVariable $this = fields::new($pkg);
    while(my($k,$v) = each %arg) {
	$this->{$k} = $v;
    }

    # further initialize the object (e.g. apply default values were no value was given)
    $this->initialize();

    return $this;
}

sub initialize { # override this method in derived() classes
    my Math::SimpleVariable $this = shift;
    defined($this->{name}) or die "No name specified for variable";
    return 1;
}

sub clone { # makes a deep copy of the object
    # You need to override clone() in derived classes carrying additional data!
    my Math::SimpleVariable $this = shift;
    return Math::SimpleVariable->new(
       name  => $this->{name},
       value => $this->{value},
    );
}

### Accessors (including useful aliases)
sub name {
    my Math::SimpleVariable $this = shift;
    return $this->{name};
}

sub id {
    my Math::SimpleVariable $this = shift;
    return $this->name();
}

sub value {
    my Math::SimpleVariable $this = shift;
    return $this->{value};
}

sub evaluate {
    my Math::SimpleVariable $this = shift;
    return $this->value();
}

### I/O
sub stringify {
    my Math::SimpleVariable $this = shift;
    return $this->name();
}


1;

__END__