All present, and this time the meeting actually ended on time.

• We discussed the situation with the apostrophe package separator removal. We continue to keep an eye on things but it now feels close to inevitable that we will use a feature to disable it conditionally.
• We briefly touched on the removal of smartmatch, where both the extent of the situation and our thoughts so far are much less clear.
• Connected to all that, we discussed some general thoughts on how not to keep finding ourselves in the same situation with changes like this, but found we probably already have all the mechanisms we need.
• We decided that the provisions of the PPC process are the right way for pre-PPC “Signature named parameters” to play out so it has now become PPC 0024 with status “Exploratory”.
• We took another brief look at the closure memory leak which is now #22547 and resolved to prepare to put down a consensus next time we meet.

[P5P posting of this summary]

These are some answers to the Week 285, Task 2, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days from now (on September 8, 2024, at 23:59). This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 2: Making Change

Compute the number of ways to make change for given amount in cents. By using the coins e.g. Penny, Nickel, Dime, Quarter and Half-dollar, in how many distinct ways can the total value equal to the given amount? Order of coin selection does not matter.

A penny (P) is equal to 1 cent.
A nickel (N) is equal to 5 cents.
A dime (D) is equal to 10 cents.
A quarter (Q) is equal to 25 cents.
A half-dollar (HD) is equal to 50 cents.

Yep, that's right - the second half dozen talks have been accepted for this year's London Perl and Raku Workshop. This puts our schedule at approximately 80% full, so if you are thinking about talking at the workshop then submit your proposal now!

The CFP will be closed at the end of September to give speakers sufficient time to finish their presentations and to allow the schedule to be created. We encourage all attendees to mark talks they are interested in as that will inform some of the schedule choices.

If you aren't thinking about talking then have a think about what you've been doing in the Perl and/or Raku space the last five years, or even just the general IT and development space. Perhaps there's something interesting you can talk about? If you don't feel it's a full fat talk then submit a lightning talk instead.

The London Perl and Raku Workshop will take place on 26th Oct 2024. Thanks to this year's sponsors, without whom LPW would not happen:

• Deriv
• CV-Library
• Geekuni
• Geizhals Preisvergleich
• Datensegler e.U.
• SpareRoom

If you would like to sponsor LPW then please have a look at the options here: https://act.yapc.eu/lpw2024/sponsoring.html

In which thousands become millions, as we achieve a near-linear solution.

Back from holidays all three of us were in.

• We discussed the recently reported closure memory leak in 5.40, which existed in older perls and was fixed in a way that caused other breakage instead, and we agreed that if it isn’t fixable we need to address it by at least providing guidance on how to code around it
• We discussed the removal of apostrophe as a package separator, and agreed that it should likely be feature-guarded, but the verdict on the fallout is not yet in
• We continued the discussion on how to simultaneously encourage low ecosystem churn while helping users enjoy all the latest goodies
• We agreed on writing a few position paper articles to explain our thinking and the attitude we think a PSC should take

[P5P posting of this summary]

These are some answers to the Week 283, Task 2, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 2: Digit Count Value

You are given an array of positive integers, @ints.

Write a script to return true if for every index i in the range 0 <= i < size of array, the digit i occurs exactly the $ints[$i] times in the given array otherwise return false.

Example 1

Perl v5.40 introduced native true and false keywords. Unfortunately not all CPAN modules are ready to use them. One of those not yet ready is Mojo::Pg.

Normally you'd want to pass booleans to your queries as just 1's and 0's. However, since Mojo::JSON's true & false stringify to 1 and 0, my 5.38-using codebase is full of Mojo::Pg queries with Mojo::JSON's true and false as arguments.

This is a problem if I want to upgrade the perl interpreter of that project to Perl v5.40, because if I write "use v5.40;" in the file that contains those boolean keywords, Perl's builtin booleans will be used instead, which don't stringify to 1 and 0, but to 1 and the empty string, which can't be used by DBD::Pg in boolean fields and makes DBD::Pg throw an exception.

The solution I found was to subclass Mojo::Pg::Database, and wrap the query method, so that if Perl's builtin booleans are found, they are replaced in the query with native Pg booleans.

The source of the module and a lot more information can be found in my blogpost, here.

Problem

I have not been able to figure out how to run an async thread in the background while using a REPL like reply. The moment I run the main loop, it takes over the input from the REPL. Here's what a typical failed REPL session might look like.

Just Aristotle and Philippe this time (Graham chipped in on IRC):

• we discussed the apostrophe situation: we will watch 5.41.3 break CPAN, and then evaluate the actual fallout. We like the idea of guarding this with a feature (which might need to be split in two, for the string interpolation case)
• we had a long discussion about backwards compatibility and use VERSION. Should "did you use VERSION?" become the new "did you use strict and warnings?"

[P5P posting of this summary]

These are some answers to the Week 283, Task 1, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days from now (on August 25, 2024, at 23:59). This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 1: Unique Number

You are given an array of integers, @ints, where every element appears more than once except one element. ` Write a script to find the one element that appears exactly one time.

Example 1

Input: @ints = (3, 3, 1)
Output: 1

Example 2

Input: @ints = (3, 2, 4, 2, 4)
Output: 3

Example 3

Sometimes one needs an extra ounce of performance. Why not combine the high level semantics of Perl with the punch of assembly?

This repo includes various examples of how this can be done.

Just Graham and Aristotle this time.

• Discussed some patches to include in a perl 5.38 or 5.40 point release.
• We will be watching the fallout from the removal of apostrophe as package separator.
• Discussed what could be done for lexical method calls.

[P5P posting of this summary]

These are some answers to the Week 282, Task 2, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days from now (on August 18, 2024, at 23:59). This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 2: Changing Keys

You are given an alphabetic string, $str, as typed by user.

Write a script to find the number of times user had to change the key to type the given string. Changing key is defined as using a key different from the last used key. The shift and caps lock keys won’t be counted.

Example 1

This block of code is valid Perl:

if (my $var1 = calc1()) {
    say $var1;
} elsif (my $var2 = calc2()) {
    say "$var1, $var2";
}

As you can see, $var1, which is declared in the if clause, is visible inside the elsif clause too.

Perl never ceases to amaze me!

(Also appears in my blog)

Chapter 3 of Higher Order Perl describes various approaches to memoization of an expensive function: private cache and the Memoize module. The book was written in 2005 (Perl was at version 5.8 back then) , so it does not include another way for function caching that is now available : caching through state variables (introduced in Perl 5.10). The Fibonacci example considered in HOP also requires the ability to initialize state hash variables (available since Perl 5.28). The code below contrasts the implementation with a state variable v.s. the memoize module:

I remember when one one of my grandchildren helpfully decided reorganise a bookshelf whilst by himself. Upon being discovered, sitting in front of an empty shelf with books strewn all around him, his instinctive reaction made me feel proud to be his grandpa. He looked up and said, “Oh dear! Oh dear! what happened?”, as if this calamity had occurred spontaneously, astonishing him as much as the angry parent who was going to have to tidy it all up. It is hard to hide amusement when you watch your kids have to deal with their kids.

Advanced Disaster Management Strategy for Grandchildren and Programmers

These are some answers to the Week 281, Task 1, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days from now (on August 18, 2024, at 23:59). This blog post provides some solutions to this challenge. Please don’t read on if you intend to complete the challenge on your own.

Task 1: Good Integer

You are given a positive integer, $int, having 3 or more digits.

Write a script to return the Good Integer in the given integer or -1 if none found.

A good integer is exactly three consecutive matching digits.

Example 1

Input: $int = 12344456
Output: "444"

Example 2

Input: $int = 1233334
Output: -1

Example 3

This week, the whole PSC was in attendance.

We merged HTTP-Tiny#6, and then discussed a number of topics:

• some improvements on the process for releasing blead-upstream dual-life modules are needed
• the instructions for releasing a new Perl are difficult to follow and partly redundant, the process takes longer than it should, and more of it could be automated
• the pumpkin permission list has grown over time, and probably needs to be trimmed
• more talk about Markdown documentation
• thoughts on how to strike a better balance with the verbosity/brevity of meeting minutes

Brett Estrade, did it again with yet another excellent talk at TPRC 2024 about the use of OpenMP for parallelizing Perl/C code. This is an area that is extremely interesting as OpenMP is a rather straightforward way to parallelize code using simple compiler pragmas in Inline::C sections of code. Furthermore, as I discussed at TPRC2024, the combination of the Many Core Engine (MCE) and OpenMP allow the Perl user to endow a specific piece of code with both process and thread level parallelism, bleeding the hardware for performance without losing the benefits of Perl for high level coding.

Since this an area that may not be familiar to many users, I decided to start blogging about Perl/C parallel application programming at Killing It With Perl . The first post in this series is about a rudimentary control of the OpenMP environment , e.g. setting up the number and scheduling of the threads and you can read all about it here.