Re: Using Exporter module

Not exporting a sub doesn't prevent it from being called. Exporting simply allows you to do sub() instead of doing Module::sub(). Functions which aren't imported can still be called

using their fully qualified name (Module::sub()),
as a class method (Module->sub()),
as an object method ($o->sub()), and
using a code ref ($sub->())

Perl doesn't provide a means of making a function uncallable from outside of a namespace. There are ways of making it harder to call a function, but most programmers are satisfied to signal that a function is for private use by prepending an underscore (_) to its name.

Update: By the way, it's totally useless to export methods unless they can also be called as functions. It looks to me like you don't need Exporter at all.

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Re^2: Using Exporter module by perlCrazy (Monk) on Jul 18, 2007 at 19:51 UTC
Thanks for reply. What is the way to stop exporting all functions in calling program ? is there any way or I am just trying to do things that is not possible.	[reply]
Re^3: Using Exporter module by ikegami (Patriarch) on Jul 18, 2007 at 20:04 UTC
Exporting doesn't mean what you think it does, at least not in Perl. To export is to remove the requirement to use a fully qualified name. What you really want, it seems, is to make a function uncallable from outside of {something}. (A namespace? Code that originated from a certain file?) Perl doesn't provide any direct means of doing that. Perl considers this a documentation issue. If a user of your module disreguards your documentation and call a function he shouldn't, it's his own foot he's shooting. Many programmers prepend an underscore (`_`) to the name of their private subs/methods as an indication that they shouldn't be called.	[reply] [d/l]
Re^4: Using Exporter module by Joost (Canon) on Jul 18, 2007 at 22:45 UTC
In general, you're right. But... It is possible to make subroutines un-callable from a scope, it just makes the code uglier :-) `package Whatever; { # anything outside this scope can't call this: my $private1 = sub { print "hello"; }; # everybody can call Whatever::foo sub foo { $private1->(); # call private method print " world\n"; } } foo();` [download] "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]
Re^5: Using Exporter module by ikegami (Patriarch) on Jul 19, 2007 at 14:32 UTC
Re^4: Using Exporter module by perlCrazy (Monk) on Jul 19, 2007 at 12:42 UTC
I think we can acheive this by creating private method. and not call like $self->_method() Inside module if we call the private method like this: _method($self,arguments.) and if we try to call this subroutine outside then this will thorw an error.	[reply]