Anonymous Monk: Note also that in a file containing multiple package namespaces, a block structure can be very useful to achieve complete lexical isolation within each package:
package Foo { my $private; ...; ... } # perl version 5.14+
package Bar { my $private; ...; ... }
or (note required semicolon after package statement)
{ package Foo; my $private; ...; ... } # pre-5.14 perl
{ package Bar; my $private; ...; ... }
(The pre-5.14 scoping will, of course, continue to work with version 5.14+.) And definitely make use of the life-simplifying parent module!
Update: And in any version of Perl 5, this scoping can be used to implement absolutely private package/class functions/methods:
(This assumes that all these separate packages are contained in a standard .pm module that is use-ed or require-ed in the, well, usual way so that phasing problems are eliminated — or at least minimized.) The naming is a bit misleading in that both the $private_class_method and $private_object_method methods can be invoked with either a class name or an object reference, although what you do with the class name/object reference therein is another story! But they're still private.package Foo { ... my @stuff = ( ... ); # initialized upon inclusion ... my $private_function = sub { ... }; ... my $private_class_method = sub { my $class = shift; ...; }; my $private_object_method = sub { my $obj_ref = shift; ...; }; ... $private_function->(@stuff); ... $class_name->$private_class_method(...); $object_reference->$private_object_method(...); ... }
All this, it must be said, starts to sound like a real OO system, of which there are many thorough-going implementations in CPAN.
Give a man a fish: <%-{-{-{-<
In reply to Re^2: Multiple Packages in a Module?
by AnomalousMonk
in thread Multiple Packages in a Module?
by Anonymous Monk
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