NAME

Module::Extract::Use - Discover the modules a module explicitly uses

SYNOPSIS

        use Module::Extract::Use;

        my $extor = Module::Extract::Use->new;

        my @modules = $extor->get_modules( $file );
        if( $extor->error ) { ... }

        my $details = $extor->get_modules_with_details( $file );
        foreach my $detail ( @$details ) {
                printf "%s %s imports %s\n",
                        $detail->module, $detail->version,
                        join ' ', @{ $detail->imports }
                }

DESCRIPTION

Extract the names of the modules used in a file using a static analysis. Since this module does not run code, it cannot find dynamic uses of modules, such as eval "require $class". It only reports modules that the file loads directly or are in the import lists for parent or base.

The module can handle the conventional inclusion of modules with either use or require as the statement:

        use Foo;
        require Foo;

        use Foo 1.23;
        use Foo qw(this that);

It now finds require as an expression, which is useful to lazily load a module once (and may be faster):

        sub do_something {
                state $rc = require Foo;
                ...
                }

Additionally, it finds module names used with parent and base, either of which establish an inheritance relationship:

        use parent qw(Foo);
        use base qw(Foo);

In the case of namespaces found in base or parent, the value of the direct method is false. In all other cases, it is true. You can then skip those namespaces:

        my $details = $extor->get_modules_with_details( $file );
        foreach my $detail ( @$details ) {
                next unless $detail->direct;

                ...
                }

This module does not discover runtime machinations to load something, such as string evals:

        eval "use Foo";

        my $bar = 'Bar';
        eval "use $bar";

If you want that, you might consider Module::ExtractUse (a confusingly similar name).

new

Makes an object. The object doesn't do anything just yet, but you need it to call the methods.

init

Set up the object. You shouldn't need to call this yourself.

get_modules( FILE )

Returns a list of namespaces explicity use-d in FILE. Returns the empty list if the file does not exist or if it can't parse the file.

Each used namespace is only in the list even if it is used multiple times in the file. The order of the list does not correspond to anything so don't use the order to infer anything.

get_modules_with_details( FILE )

Returns a list of hash references, one reference for each namespace explicitly use-d in FILE. Each reference has keys for:

        namespace - the namespace, always defined
        version   - defined if a module version was specified
        imports   - an array reference to the import list
        pragma    - true if the module thinks this namespace is a pragma
        direct    - false if the module name came from parent or base

Each used namespace is only in the list even if it is used multiple times in the file. The order of the list does not correspond to anything so don't use the order to infer anything.

error

Return the error from the last call to get_modules.

TO DO

SEE ALSO

Module::ScanDeps, Module::Extract

SOURCE AVAILABILITY

The source code is in Github:

        https://github.com/briandfoy/module-extract-use

AUTHOR

brian d foy, <bdfoy@cpan.org>

COPYRIGHT AND LICENSE

Copyright © 2008-2020, brian d foy <bdfoy@cpan.org>. All rights reserved.

This project is under the Artistic License 2.0.