NAME

Perl::PrereqScanner::Lite - Lightweight Prereqs Scanner for Perl

SYNOPSIS

    use Perl::PrereqScanner::Lite;

    my $scanner = Perl::PrereqScanner::Lite->new;
    $scanner->add_extra_scanner('Moose'); # add extra scanner for moose style
    my $modules = $scanner->scan_file('path/to/file');

DESCRIPTION

Perl::PrereqScanner::Lite is the lightweight prereqs scanner for perl. This scanner uses Compiler::Lexer as tokenizer, therefore processing speed is really fast.

METHODS

new($opt)

Create a scanner instance.

$opt must be hash reference. It accepts following keys of hash:

extra_scanners
It specifies extra scanners. This item must be array reference.

e.g.
```
    my $scanner = Perl::PrereqScanner::Lite->new(
        extra_scanners => [qw/Moose Version/]
    );
    
```
See also "add_extra_scanner($scanner_name)".
no_prereq
It specifies to use "## no prereq" or not. Please see also "ADDITIONAL NOTATION".

scan_file($file_path)

Scan and figure out prereqs which is instance of "CPAN::Meta::Requirements" by file path.

scan_string($string)

Scan and figure out prereqs which is instance of "CPAN::Meta::Requirements" by source code string written in perl.

e.g.

    open my $fh, '<', __FILE__;
    my $string = do { local $/; <$fh> };
    my $modules = $scanner->scan_string($string);

scan_module($module_name)

Scan and figure out prereqs which is instance of "CPAN::Meta::Requirements" by module name.

e.g.

    my $modules = $scanner->scan_module('Perl::PrereqScanner::Lite');

scan_tokens($tokens)

Scan and figure out prereqs which is instance of "CPAN::Meta::Requirements" by tokens of Compiler::Lexer.

e.g.

    open my $fh, '<', __FILE__;
    my $string = do { local $/; <$fh> };
    my $tokens = Compiler::Lexer->new->tokenize($string);
    my $modules = $scanner->scan_tokens($tokens);

add_extra_scanner($scanner_name)

Add extra scanner to scan and figure out prereqs. This module loads extra scanner such as "Perl::PrereqScanner::Lite::Scanner::$scanner_name" if specifying scanner name through this method.

If you want to specify an extra scanner from external package without "Perl::PrereqScanner::Lite::" prefix, you can prepend "+" to $scanner_name. Like so "+Your::Awesome::Scanner".

Extra scanners that are default supported are followings;

Perl::PrereqScanner::Lite::Scanner::Moose
Perl::PrereqScanner::Lite::Scanner::Version

ADDITIONAL NOTATION

If "no_prereq" is enabled by "new()" (like so: "Perl::PrereqScanner::Lite->new({no_prereq => 1})"), this module recognize "## no prereq" optional comment. The requiring declaration with this comment on the same line will be ignored as prereq.

For example

    use Foo;
    use Bar; ## no prereq

In this case "Foo" is the prereq, however "Bar" is ignored.

SPEED COMPARISON

Plain

                                Rate   Perl::PrereqScanner Perl::PrereqScanner::Lite
    Perl::PrereqScanner       8.57/s                    --                      -97%
    Perl::PrereqScanner::Lite  246/s                 2770%                        --

With Moose scanner

                                Rate   Perl::PrereqScanner Perl::PrereqScanner::Lite
    Perl::PrereqScanner       9.00/s                    --                      -94%
    Perl::PrereqScanner::Lite  152/s                 1587%                        --

NOTES

This is a quotation from <https://github.com/moznion/Perl-PrereqScanner-Lite/issues/13>.

Yes, it's true. This design is so ugly and not smart. So I have to redesign and reimplement this module, and I have some plans.

If you have a mind to expand this module by implementing external scanner, please be careful. Every "scan_*" calls must not affect to any others through the singleton of this module (called it $c in <https://github.com/moznion/Perl-PrereqScanner-Lite/blob/c03638b2e2a39d92f4d7df360af5a6be65dc417a/lib/Perl/PrereqScanner/Lite/Scanner/Moose.pm#L8>).

LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

moznion <moznion@gmail.com>