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perl-minimumversion-fast's Introduction

NAME

Perl::MinimumVersion::Fast - Find a minimum required version of perl for Perl code

SYNOPSIS

use Perl::MinimumVersion::Fast;

my $p = Perl::MinimumVersion::Fast->new($filename);
print $p->minimum_version, "\n";

DESCRIPTION

"Perl::MinimumVersion::Fast" takes Perl source code and calculates the minimum version of perl required to be able to run it. Because it is based on goccy's Compiler::Lexer, it can do this without having to actually load the code.

Perl::MinimumVersion::Fast is an alternative fast & lightweight implementation of Perl::MinimumVersion.

This module supports only Perl 5.8.1+. If you want to support Perl 5.6, use Perl::MinimumVersion instead.

In 2013, you don't need to support Perl 5.6 in most of case.

METHODS

my $p = Perl::MinimumVersion::Fast->new($filename);
my $p = Perl::MinimumVersion::Fast->new(\$src);

Create new instance. You can create object from $filename and \$src in string.
$p->minimum_version();

Get a minimum perl version the code required.
$p->minimum_explicit_version()

The minimum_explicit_version method checks through Perl code for the use of explicit version dependencies such as.
```
  use 5.006;
  require 5.005_03;
```
Although there is almost always only one of these in a file, if more than one are found, the highest version dependency will be returned.

Returns a version object, undef if no dependencies could be found.
$p->minimum_syntax_version()

The minimum_syntax_version method will explicitly test only the Document's syntax to determine it's minimum version, to the extent that this is possible.

Returns a version object, undef if no dependencies could be found.
version_markers

This method returns a list of pairs in the form:
```
  ($version, \@markers)
```
Each pair represents all the markers that could be found indicating that the version was the minimum needed version. @markers is an array of strings. Currently, these strings are not as clear as they might be, but this may be changed in the future. In other words: don't rely on them as specific identifiers.

BENCHMARK

Perl::MinimumVersion::Fast is faster than Perl::MinimumVersion. Because Perl::MinimumVersion::Fast uses Compiler::Lexer, that is a Perl5 lexer implemented in C++. And Perl::MinimumVersion::Fast omits some features implemented in Perl::MinimumVersion.

But, but, Perl::MinimumVersion::Fast is really fast.

                            Rate Perl::MinimumVersion Perl::MinimumVersion::Fast
Perl::MinimumVersion       5.26/s                   --                       -97%
Perl::MinimumVersion::Fast  182/s                3365%                         --

LICENSE

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

THANKS TO

Most of documents are taken from Perl::MinimumVersion.

AUTHOR

tokuhirom [email protected]

--- perlver-fast    2020-12-07 10:51:32.525958806 +0100
+++ perlver-fast    2020-12-07 10:51:58.686278929 +0100
@@ -10,6 +10,6 @@ if (@ARGV) {
     }
 } else {
     my $src = join("", <>);
-    my $v = Perl::MinimumVersion::Fast->new($src);
-    printf "%s: %s\n", $_, $v->minimum_version;
+    my $v = Perl::MinimumVersion::Fast->new(\$src);
+    printf "%s: %s\n", "STDIN", $v->minimum_version;
 }

And as addition, I want support for -e :)
So my current version looks like

#!/usr/bin/env perl
use strict;
use warnings;
use Getopt::Long qw(:config bundling passthrough);
use Perl::MinimumVersion::Fast;

GetOptions (
    "e:s" => \my $expr,
    "v"   => \my $verbose,
    ) or die;

if (@ARGV) {
    report ($_, $_) for @ARGV;
    }
elsif ($expr) {
    report ("-e", \$expr);
    }
else {
    my $src = do { local $/; <> };
    report ("STDIN", \$src);
    }

sub report {
    my ($in, $src) = @_;
    my $v = Perl::MinimumVersion::Fast->new ($src);
    printf "%s: %s / %s\n", $in, $v->minimum_version, $v->minimum_syntax_version;
    $verbose or return;
    my @markers = $v->version_markers;
    while (@markers) {
        my ($pv, $m) = splice @markers, 0, 2;
        printf "%-10s %s\n", $pv, $_ for @$m;
        }
    }

Demo

$ perlver-fast -e '$b = ($a // "foo) =~ s{f\K}{i}r'
-e: 5.010 / 5.010

$ perlver-fast -ve '$b = ($a // "foo) =~ s{f\K}{i}r'
-e: 5.010 / 5.010
5.010      // operator

But it still does not report the use of \K and s{}{}r

Stacked file-test was introduced in 5.10.0

$ perlver-fast -e'-e -f -s ".exrc" and print "1\n"'
-e: 5.006 / 5.006

Stacked file-test was introduced in 5.10.0. It should report 5.10.0 instead of 5.006

$ perl5.8.9 -we '-e -f -s ".exrc" and print "1\n"'
Use of uninitialized value in -e at -e line 1.

$ perl5.10.0 -we '-e -f -s ".exrc" and print "1\n"'
1

No documentation of supported features

It appears there's no documentation of what features are detected, and hence what perl versions are supported.

Starting with Perl 5.14, "unshift" can take a scalar EXPR, which must hold a reference to an unblessed array.

This check tripped me up in Dist::Zilla::Plugin::Authority v1.008 when using Perl::MinimumVersion and I wanted to check this module just in case you reproduced the bug too.

Unfortunately, this module only fared better as it determined the following code's minimum is 5.008 when it actually should be 5.14! Perl::MinimumVersion did worse, returning 5.006 so please don't feel bad ;)

https://github.com/apocalypse/perl-dist-zilla-plugin-authority/blob/master/lib/Dist/Zilla/Plugin/Authority.pm#L239 which was

unshift $block->{children},
PPI::Token::Whitespace->new("\n"),
$self->_make_authority( $package ),
PPI::Token::Whitespace->new("\n");

I'm not sure if it is "easy" to check if $block->{children} is an arrayref or not? Maybe that's the reason why it failed to detect this? Thanks for looking into this!

Detects empty regex as defined-or

This file is said to require 5.010 because // operator:

use strict;
use warnings;

my $what = <>;
my @chars = split //, $what;
print "@chars\n";

requires Compiler::Lexer

This module requires Compiler::Lexer which requires a C++ compiler which is not available on many systems, esp if wanted on esoteric OS's like AIX or HP-UX.

As Compiler::Lexer gives no (easy) path to select a C++ compiler that is not in your $PATH (or is not recognized by default), the very useful module (Perl-MinimumVersion-Fast) cannot be used on systems where Compiler::Lexer cannot be built. Not your fault, but for sure annoying.

Hope you can find a working alternative that does not require C++ or G++

normal when should be 5.010 not 5.012

the first when is treated as postfix
the second when as normal

sample from http://perldoc.perl.org/5.14.1/functions/given.html

#!/usr/bin/env perl 
use v5.10;
given ($fruit) {
  when (/apples?/) {
    print "I like apples."
  }
  when (/oranges?/) {
    print "I don't like oranges."
  }
  default {
    print "I don't like anything"
  }
}

see for your self with following

#!/usr/bin/env perl 
use 5.012004;
use strict;
use warnings FATAL => 'all';

use English qw( -no_match_vars );    # Avoids reg-ex performance penalty
local $OUTPUT_AUTOFLUSH = 1;

use utf8;
use Carp::Always::Color;
use Compiler::Lexer;
use Data::Printer {caller_info => 1, colored => 1,};
use autodie qw(open close);

my $filename = $ARGV[0];

open my $fh, '<', $filename;
my $script = do { local $INPUT_RECORD_SEPARATOR; <$fh> };

# p $script;

my $lexer = Compiler::Lexer->new($filename);

# p $lexer;

my $tokens = $lexer->tokenize($script);
#p @tokens;
my @tokens = map { @$$_ } $tokens;

for my $i (0..@tokens-1) {
  my $token = $tokens[$i];
#p $token;

  if ($token->{name} eq 'WhenStmt') {
p $token;


    if (
      $i >= 1
      && ( $tokens[$i - 1]->{name} ne 'SemiColon'
        && $tokens[$i - 1]->{name} ne 'RightBrace')
      )
    {
      say 'postfix when => 5.012';
    }
    else {
      say 'normal when => 5.010';
    }
  }

}

#p $lexer->get_groups_by_syntax_level($$tokens, Compiler::Lexer::SyntaxType::T_Stmt);

## p $lexer->get_used_modules($script);

  exit(0);

__END__

tokuhirom / perl-minimumversion-fast Goto Github PK

perl-minimumversion-fast's Introduction

NAME

SYNOPSIS

DESCRIPTION

METHODS

BENCHMARK

LICENSE

THANKS TO

AUTHOR

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