Java Archives

Perl5 to Java compiler - first release

This is the first release of the Perl5 to Java compiler.

In the github page there is a link to the "jar" file and the lib directories for JVM-specific Perl modules.

The "perlito5.jar" file provides a perl-like command line:

java -jar perlito5.jar -I src5/lib -e ' print "hello, World!\n" '

Note that you don't need to compile a Java file. Perlito5 now compiles the Perl code to JVM bytecode in memory and executes it. Also eval-string is executed as JVM bytecode - there is no interpreter.

Perlito5 is an implementation of the Perl5 language. It is work-in-progress. It provides an impressive coverage of Perl features, but it will not run most existing Perl programs due to platform differences.

More details in the GitHub Perlito5-Java page:

Perl5 to Java compiler - week 100 - bootstrapping

It's been a 100 weeks since the Perl5 to Java compiler started.

The compiler is now "good enough" to translate itself to Java.

# grab a copy of the project
$ git clone ; cd Perlito

$ make clean

# create the "" file
$ perl --bootstrapping -Isrc5/lib -Cjava src5/util/ >

# compile to ".class"
$ time javac -J-Xms2000m -J-Xmx2000m -J-Xss2000m -source 7
[ scary warnings ]

# create the perlito5.jar file
$ jar -cfe perlito5.jar Main *.class

# quick check
$ java -jar perlito5.jar -v
This is Perlito5 9.021, an implementation of the Perl language.

# run a test
$ java -jar perlito5.jar --bootstrapping -Isrc5/lib -Cjava t5/unit/array.t > ; javac -source 7 ; java Main
[ scary warnings ]
ok 1 - create array
ok 2 - set element

# test the bootstrapping
$ java -jar perlito5.jar --bootstrapping -Isrc5/lib -Cjava src5/util/ >
$ diff
[ no differences ]

The "--bootstrapping" flag tells the compiler that eval-string is not available. Eval-string is not yet implemented.

Perl5 to Java compiler - using a Perl module from Java

Perlito5 now supports calling Perl subroutines from Java.

For example, a Perl module was compiled to "", and it can be called using:

 class TestPerl {
    public static void main(String[] args) throws Exception {
        // initialize the Perl module - setup global variables
        // and create the subroutine entries
        // locate the subroutine main::test
        // and call it with an argument list
        // that is: @res = main::test(123)
        PlObject[] res = Main.apply("main::test", new String[]{ "123" });
        // do something with the results
        for (PlObject s: res) {
            System.out.println("Java result: " + s.toString());

Perl5 to Java compiler - 2nd hackathon

We've had another hackathon at work. This time Bosko, Bruno, Frederico, Yati, and I hacked on the Perlito Perl5-to-Java compiler.

We started adding unit tests - so that we can automatically extract a list of implemented features; the existing Perl tests are not properly organized "by feature".

The latest additions to the Java backend are:

Perlito - reviewing some older code

Today I've finally updated the Perlito compiler ChangeLog, this covers a little more than a year of commits.

The most significant update was the new Perlito5-to-Java backend, which is work-in-progress. It covers a lot of ground, but there is a lot more.

There were also some interesting new Perlito5-to-Javascript features, such as regex /e modifier, and file operators support in nodejs.

The Perl6 backends have not been updated, but things still work.

While reviewing the README-perlito6 file, I've found some interesting stuff that I haven't touched in a while - here is a piece of generated code that goes through 3 different languages:

Perl5 to Java compiler is 1 month old, and we have a hackathon

We are having a hackathon at work, and Bosko, John and I have hacked together a working Perl script that executes in a Java environment (HBase).

a perl5 to Java compiler - first benchmark

I've written a small performance test. And it is not bad!

First perl:

$ time perl misc/benchmark/
done 64000000

real    0m3.964s
user    0m3.963s
sys     0m0.004s

And then Perl-in-Java:

$ touch Test.class ; rm Test.class ; perl -Isrc5/lib -I. -It -Cjava misc/benchmark/ > ; javac ; time java Main
done 64000000

real    0m0.840s
user    0m0.584s
sys     0m0.302s

[EDIT] broken link

a perl5 to Java compiler - week 3

The compiler now has a small test suite. The main additions in the last 10 days were implementing global variables, better support for references, data structures, string interpolation, and a few new subroutines in the CORE namespace and operators.

About Flávio S. Glock

user-pic I blog about Perl.