Quoting "Th. J. van Hoesel" <th.j.v.hoe...@gmail.com>:
Hello,
As agreed upon with Dave Cross, I would make some really cool
changes to his module Number::Fraction - I as former math teacher
love fraction.
However, can someone point me out what is happening between lines
132 and 144 of Fraction.pm ? This part is the neatest part of the
module, where it enables the module to use constants in your Perl
programs.
Here's the code on github:
https://github.com/davorg/number-fraction/blob/master/lib/Number/Fraction.pm#L132
And here's the relevant section of the overload.pm documentation:
http://perldoc.perl.org/overload.html#Overloading-Constants
my %_const_handlers =
(q => sub { return __PACKAGE__->new($_[0]) || $_[1] });
This defines a subroutine that Perl will use to parse any quoted
strings. If Number::Fraction->new can construct an object out of them,
it will. Otherwise new() returns false and the original string is used
instead.
=head2 import
Called when module is C<use>d. Use to optionally install constant
handler.
=cut
sub import {
overload::constant %_const_handlers if $_[1] and $_[1] eq ':constants';
}
And this installs the constant handler if the module is used with the
correct argument (use Number::Fraction ':constants').
Should really give users the option to uninstall that handler too, I guess.
Cheers,
Dave...
