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).

SEE ALSO

Perl::PrereqScanner, Compiler::Lexer

LICENSE

Copyright (C) moznion.

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