Talk Slides and Recording: "Faster Perl 6 Programs"

Read this article on Rakudo.Party

Last week I gave a "Faster Perl 6 Programs" talk at the Toronto Perl Mongers, whom I thank for letting me speak.

For google hangout that is usually set up, we got to use the fancy equipment provided by the company that was letting us use their space. Unfortunately, it's currently unclear if the hangout was recorded and if there would be a video of the talk.

So, I figured I'd make a screencast of the talk. You won't get some of the discussions that occurred during the meeting, but the content of the talk itself is pretty much identical.

You can view the slides at and the screencast of the talk is on YouTube:

Condiment Moose

It is catch up day here in the Moose-Pen.

I was just about to add in the next operator on my, the 'Like' command but before I did that I added a few more tests for the 'in' operator and with this test;

The start of the GraalVM/Truffle experiment

Recently GraalVM 1.0 been released which can run Ruby, JavaScript and other dynamic and static languages on top at super fast speeds.
I have decided to see how Perl 6 will run on top of it.
If successful that should allow us to run Perl 6 hopefully very fast and use Java, Ruby and JavaScript libraries without paying a interoperability price.

Truffle which is what we are using is a language implementation frameworks that creates an efficient JIT from a (sufficiently annotated) AST interpreter written in Java.

The implementation lives in the 'truffle' ( branch of the nqp repo.

nqp-truffle run the first NQP test today and I expect to get many more to pass in the coming days.

I Got Six (YAPCs)

[This is my sixth YAPC / TPC—technically, my first TPC.  If you like, you can read about my other YAPC experiences: YAPC 2011, YAPC 2013, YAPC 2014, YAPC 2015, YAPC 2016.]

After missing a year last year, I came back to attend YAPC this year.  (Yes, yes: “The Perl Conference,” now.  But it’ll probably always be “YAPC” to me.)  And I actually spoke again (second time), this time on dates and my Date::Easy module.  If you missed it and are interested in watching it, the video is up.

This year was in Salt Lake City again, and, while I normally don’t like repeating cities (mainly because I like visiting new places instead), I do have to say the Little America Hotel is every bit the excellent venue that I remembered.  Plus it’s just barely close enough to where I live that I can drive there and take the whole family, and do a sort of “conferenscation.” Which is what we did.

My highlights from this year:

Cancellation of Perl 6 Constants and Rationals Grant

I've requested The Perl Foundation to cancel my currently running grant "Perl 6 Bugfixing and Performance of Rationals / Fixing Constraints on Constants" on the grounds that a more detailed investigation into proposed features that occurred during the course of the grant showed many of them to be unwanted or unimplementable.

Since any further grant's work now differs significantly from what the TPF and community voted on, I prefer to cancel the grant and perform any of the remaining work on a volunteer basis, whenever I get a chance.

No payments will be made for any of the completed work to date and it is to be deemed to have been performed on a volunteer basis.

Summary of Changes from Original Proposal and Reasons for Cancellation

In Moose

Its is in day here in the Moose-pen

Now that I have a few little API things worked out from yesterday's post I better carry on and do the next two 'operators' 'In' and 'Not In'

My original though was these two operators would now require a little parameter validation like I did for the 'Between' as most of us know the very common form of an SQL 'In' queries one like these two;

SELECT * FROM users WHERE id in (SELECT user_id FROM drivers) ;
SELECT * FROM users WHERE id in (109,100,22) ;
should just be handled by the present type and coercion code in the system but I just read that this form of SQL

SELECT * FROM users WHERE id in (SELECT user_id FROM drivers,22) ; 


A group of Perl companies are sponsoring the COED:ETHICS conference, a one-day conference on ethics for developers and technologists, which is in London on July 13th. - A new way to perldoc

For the past decade or more, has been a useful and convenient resource for viewing perl documentation online. However, it has suffered from lack of maintenance and mounting unfixed issues over the past few years. Being familiar with the excellent Mojolicious documentation site and how it also can display core perldocs, I reasoned that such features would be simple to provide in this modern framework. And so, what would become (thanks to a domain acquired by pink_mist) was born.

Publish your gitlab project to CPAN using App::pause

Many people moved from GitHub to GitLab after annoucing that microsoft bought GitHub. So did I.

After some initial problems with the settling in, it works quite well. GitLab and the integrated CI is very useful to automatically upload your projects to CPAN if all tests are positive.

The steps are quite simple:

1.) Start with some project on gitlab. It doesn’t matter which one.

2.) On gitlab you can configure the some ci settings in your project

  • in Variables you’ve to insert:
      Why here? Because you don’t want to shour your username and passwort in the build log.
      These variable are available in the CI-Job

3.) Add .gitlab-ci.yml like this example:

Fix a Moose

It fix the API (yet again) day here in the Moose-Pen

So as we all know I have been playing with the extended operators over the last few posts and I just notices something in my code;

I can enter a mixed case operator like this 'BeETween' and things will still work. This is good but I think I left a part out on the Database::Deriver side of things and in Driver ::DBI I do this;

elsif (uc($predicate->operator) eq Database::Accessor::Driver::DBI::SQL::BETWEEN) {
I uc or upper case that operator and if I take it out

--elsif (uc($predicate->operator) eq Database::Accessor::Driver::DBI::SQL::BETWEEN) {
++elsif ($predicate->operato) eq Database::Accessor::Driver::DBI::SQL::BETWEEN) {
I will obvioulsy fail my test

"Parsing left recursions"

My latest Ocean of Awareness blog post is "Parsing Left Recursions".

"A lot has been written about parsing left recursion. Unfortunately, much of it simply adds to the mystery. In this post, I hope to frame the subject clearly and briefly."

Long Import Lists (and available strategies for managing them)

I ran across this the other day while writing some sample code for the next chapter of Testing Strategies for Modern Perl.

How can we use long lists of symbols from an imported package and still keep the code readable?

I usually prefer use statements of the form:
use My::Module qw(symbol1 symbol2 symbol3);

Except for specially understood modules, like Moose and Test::More, I don't like to just import everything. Rather I like to explicitly call out only the specific symbols I need.

But what if you need to:
use My::Module qw(
    symbol1 symbol2 symbol3 symbol4 symbol5 etc and so many symbols
    that it takes up several lines all the time in every package
    that uses it

There are a few alternative approaches.

Swat v. 0.2.0

With upcoming version 0.2.0 swat removes usage of prove as internal test runner. There are some -minor- breaking changes due to this. For those who uses swat I would recommend to read GH pages docs and in case you'll need help with migration of your project to the latest swat version don't hesitate to contact me.


Alexey Melezhik

Not Null Moose

Its yet another operator day here in the Moos Pen

Hmm I could just copy and past yesterday's postette here and and in 'NOT' in the correct places to get today's 'Is Not Null' operator postette but I an not going to take the schlock path today.

As I implied it is the turn of the 'Is Not Null' operator today another very easy one for a postette ad I start with the same test as yesterday and just add Not where needed, no need for that here.

As for the Driver::DBI code I could just add in another 'else if' into that _predicate_sql' sub but I think I will take a little different approach and have one 'elsif' that covers both. Here is the patch

Perl 6 Colonpairoscopy

Read this article on Rakudo.Party

If I were to pick the most ubiquitous construct in the Perl 6 programming language, it'd most definitely be the colonpair. Hash constructors, named arguments and parameters, adverbs, and regex modifiers—all involve the colonpair. It's not surprising that with such breadth there would be many shortcuts when it comes to constructing colonpairs.

Today, we'll learn about all of those! Doing so will have us looking at the simplest as well as some of the more advanced language constructs, so if parts of this article make you scratch your head, don't worry—you don't have to learn all of it at once!

PART I: Creation


The colonpair gets its name from (usually) being a Pair object constructor and (usually) having a colon in it. Here are some examples of colonpairs:

"Marpa and combinator parsing"

"Marpa and combinator parsing" -- the Marpa algorithm as the basis of better combinator parsing.

This is the second post of a pair on my Ocean of Awareness blog. (The first one was "Marpa and procedural parsing")

More intelligent searches in Geo::Coder::Free - part 2

Being lazy, I thought to myself, "when using the web interface, why should I need to add my country to the query?". So, using CGI::Lingua which is already available via the VWF system used to build the site, you longer need to do that. From the US, try this:

curl ',+Bethesda,+MD'

With VWF it was a minor change:

$rc = $geocoder->geocode(location => $q);

if(!defined($rc)) {

if(my $country = $self->{_lingua}->country()) {

$rc = $geocoder->geocode(location => "$q, $country");


return '{}' if(!defined($rc));


Null Moose

It is operator carry on day in the Moose-Pen

Just a quick postette on adding in another operator to Driver::DBI. Today I am adding the 'Is Null' operator. First of course a set of tests to add into '32_where_operators.t' along this vain;

Perl 6 CaR TPF Grant: Monthly Report (June, 2018)

This document is the June, 2018 progress report for The Perl Foundation's Perl 6 Constant and Rationals Grant.


The bonus deliverable "Perl 6 Numerics" Language documentation page was merged to master. It describes all of the available Perl 6 numerics, their interactions, suitability, and hierarchy.

The bulk of work on constants also has been merged to post-release-2018.06 branch, which will be merged to master after this month's release. I wrote 200 spec tests, available in S04-declarations/constant-6.d.t spec file, and about 500 words of documentation to cover this work.


Since my last report, I first continued working on Rationals, focusing on three pieces of work that currently reside in car-grant-unreduce branch

  1. Fixing the rare data race and doing some optimizations
  2. Fixing bad math in some ops with Zero-Denominator Rationals (ZDRs)
  3. Attempting a trial implementation where ZDRs are marked with a role, allowing us to improve performance of some operators.

"Marpa and procedural parsing"

The newest post on the "Ocean of Awareness" blog is "Marpa and procedural parsing" : Marpa's procedural parsing is more flexible and more powerful than recursive descent's.

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