Inline::Perl5
use DBI:from<Perl5>;
my $dbh = DBI.connect('dbi:Pg:database=test');
my $products = $dbh.selectall_arrayref(
'select * from products', {Slice => {}}
);
Module for executing Perl 5 code and accessing Perl 5 modules from Perl 6.
Supports Perl 5 modules including XS modules. Allows passing integers, strings, arrays, hashes, code references, file handles and objects between Perl 5 and Perl 6. Also supports calling methods on Perl 5 objects from Perl 6 and calling methods on Perl 6 objects from Perl 5 and subclass Perl 5 classes in Perl 6.
Perl 6' use statement allows you to load modules from other languages as well. Inline::Perl5 registers as a handler for the Perl5 language. Rakudo will automatically load Inline::Perl5 as long as it is installed:
use Test::More:from<Perl5>;
In Perl 6 the :ver adverb is used for requiring a minimum version of a loaded module:
use Test::More:from<Perl5>:ver<1.001014>;
Inline::Perl5's use() method maps to Perl 5's use statement:
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
$p5.use('Test::More');
To load a Perl 5 module from a specific folder:
use lib:from<Perl5> 'lib';
use MyModule:from<Perl5>;
Just list the functions or groups you want to import
use Digest::SHA1:from<Perl5> <sha1_hex>;
use Data::Random:from<Perl5> <:all>;
Inline::Perl5 creates wrappers for loaded Perl 5 modules and their functions. They can be used as if they were Perl 6 modules:
use Test::More:from<Perl5>;
plan tests => 1;
ok 'yes', 'looks like a Perl 6 function';
In this example, the plan function exported by Test::More is called.
Inline::Perl5's call($name, *@args) method allows calling arbitrary Perl 5 functions. Use a fully qualified name (like "Test::More::ok") if the function is not in the "main" namespace.
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
$p5.call('print', 'Hello World');
$p5.use('Test::More');
$p5.call('Test::More::plan', tests => 1);
Please note that since Perl 6 does not have the same concept of "context", Perl 5 functions are always called in list context.
Creating Perl 5 objects works just the same as in Perl 5: invoke their constructor (usually called "new").
use Inline::Perl5;
use Data::Dumper:from<Perl5>;
my $dumper = Data::Dumper.new;
Or using the low level methods:
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
$p5.use('Data::Dumper');
my $dumper = $p5.invoke('Data::Dumper', 'new');
Please note that since Perl 6 does not have the same concept of "context", Perl 5 methods are always called in list context.
Once you have a Perl 5 object in a variable it will behave just like a Perl 6 object. You can call methods on it like on any other object.
use IO::Compress::Bzip2:from<Perl5>;
my $bzip2 = IO::Compress::Bzip2.new('/tmp/foo.bz2');
$bzip2.print($data);
$bzip2.close;
Please note that since Perl 6 does not have the same concept of "context",
Perl 5 methods are by default called in list context. If you need to call the
method in scalar context, you can tell it so explicitly, by passing the
Scalar type object as first argument:
use IO::Compress::Bzip2:from<Perl5>;
my $bzip2 = IO::Compress::Bzip2.new(Scalar, '/tmp/foo.bz2');
$bzip2.print(Scalar, $data);
$bzip2.close(Scalar);
This may be neccessary if the Perl 5 method exposes different behavior when called in list and scalar context. Calling in scalar context may also improve performance in some cases.
Most objects in Perl 5 are blessed hash references. Some of them don't even provide accessor methods but require you to just access the hash fields directly. This works the same in Perl 6:
use Foo:from<Perl5>;
my $foo = Foo.new;
say $foo<some_attribute>;
Perl6's EVAL function supports multiple languages, just like the "use" statement. It allows for execution of arbitrary Perl 5 code given as string:
EVAL "print 'Hello from Perl 5';", :lang<Perl5>;
The low level interface to this functionality is Inline::Perl5's run($str) method:
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
$p5.run(q'
sub test {
return 'Hello from Perl 5';
}
');
Both "EVAL" and "run" return the value of the last statement in the EVAL'ed code.
Inline::Perl5 creates a Perl 5 package called "v6". This package contains a "call" function which allows for calling Perl 6 functions from Perl 5, same as Inline::Perl5's "call" method. It takes the name of the function to call and passes on any additional arguments and returns the return value of the called Perl 5 function.
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
our sub foo($str) {
say "Perl6 says hello to $str";
};
$p5.run(q:to/PERL5/);
v6::call("foo", "Perl 5");
PERL5
Perl 6 objects passed to Perl 5 functions will behave just like any other objects in Perl 5, so you can invoke methods using the -> operator.
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
$p5.run(q'
sub test {
my ($perl6) = @_;
$perl6->hello;
}
');
class Foo {
method hello {
say "Hello Perl 6";
}
}
$p5.call('test', Foo.new);
The "run" function in the automatically created "v6" package can be used to execute arbitrary Perl 6 code from Perl 5. It returns the value of the last evaluated expression in the executed code.
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
$p5.run(q:to/PERL5/);
v6::run("say foo");
PERL5
Inline::Perl5 creates a corresponding Perl 6 class for each Perl 5 module
loaded via the use Foo:from or $p5.use('Foo')
mechanisms.
You can subclass these automatically created classes as if they were original Perl 6 classes:
use Data::Dumper:from<Perl5>;
class MyDumper is Data::Dumper {
has $.bar;
method foo { say "foo!"; }
}
my $dumper = MyDumper.new([1], bar => 1);
say $dumper.Dump();
say $dumper.foo;
say $dumper.bar;
You can override methods and the overridden methods will be called even by the
Perl 5 methods in your base class. However, it is not yet possible to directly
write to the Perl 5 object's data, i.e. $self->{foo} = 1;. Read
access however is possible, i.e. my $foo = self;.
When use cannot be used to load the Perl 5 module, the
Inline::Perl5::Perl5Parent role allows can be used for subclassing.
Pass the Perl 5 package's name as parameter to the role. Pass the Inline::Perl5
object as named parameter to your classes constructor when creating objects.
$p5.run(q:heredoc/PERL5/);
package Foo;
sub test {
my ($self) = @_;
return $self->bar;
}
PERL5
class Bar does Inline::Perl5::Perl5Parent['Foo'] {
method bar {
return "Perl6";
}
}
use Inline::Perl5;
my $p5 = Inline::Perl5.new;
say Bar.new(perl5 => $p5).test;
Simply pass a Capture object containing
the object you want to pass as a reference:
$p5obj.takes-a-scalar-ref-to-str: \("the string");HASH and ARRAY references are made automatically if the Perl 6 objects
are containerized:
$p5obj.takes-an-array: [<a b c>];
$p5obj.takes-an-array-ref: $[<a b c>];CODE objects are passed by reference automatically:
$p5obj.takes-a-coderef: *.so;Regex objects are passed by reference automatically:
$p5obj.takes-a-regex: /foo/;Perl 5's exceptions (die) are translated to X::AdHoc exceptions in Perl 6 and can be caught like any other Perl 6 exceptions:
{
EVAL "die 'a Perl 5 exception!';", :lang<Perl5>;
CATCH {
when X::AdHoc {
say "Caught a Perl 5 exception: $_";
}
}
}
Perl 6's exceptions (die) are translated to Perl 5 exceptions and can be caught like any other Perl 5 exceptions:
EVAL q:to:PERL5, :lang<Perl5>;
use 5.10.0;
eval {
v6::run('die("test");');
};
say $@;
PERL5
Inline::Perl5 creates a virtual module called "v6-inline". By saying "use v6-inline;" in a Perl 5 module, you can declare that the rest of the file is written in Perl 6:
package Some::Perl5::Module;
use v6-inline;
has $.name;
sub greet {
say "Hello $.name";
}
Note that this Perl 5 module obviously will only work when Inline::Perl5 is loaded, i.e. in a Perl 6 program or if you are using Inline::Perl6 in Perl 5. This functionality is aimed at supporting Perl 5 frameworks (think Catalyst or DBIx::Class or Dancer or ...) that automatically load modules and of course expect these modules to be written in Perl 5.
You will need a perl 5 built with the -fPIC option (position independent code). Most distributions build their Perl 5 that way. When you use perlbrew, you have to build it as:
perlbrew install perl-stable -Duseshrplib
(or, if you want to use more than one Inline::Perl5 interpeter safely, for
instance from within Perl 6 threads, add the -Dusemultiplicity option as well)
If you use plenv:
plenv install 5.24.0 -Duseshrplib
If you use the perl that comes with a Linux distribution, you may need to install a separate package containing the perl library. E.g. on Debian this is called libperl-dev, on Fedora perl-libs. On openSUSE, the perl package already contains everything needed.
Build Inline::Perl5 with
perl6 configure.pl6
make
and test with
make test
and install with
make install
Stefan Seifert nine@detonation.org