These are some answers to the Week 286, 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 September 15, 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: Self Spammer

Write a program which outputs one word of its own script / source code at random. A word is anything between whitespace, including symbols.

Example 1

If the source code contains a line such as: 'open my $fh, "<", "ch-1.pl" or die;'
then the program would output each of the words { open, my, $fh,, "<",, "ch-1.pl", or, die; }
(along with other words in the source) with some positive probability.

Example 2

Technically 'print(" hello ");' is *not* an example program, because it does not
assign positive probability to the other two words in the script.
It will never display print(" or ");

Example 3

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]

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.

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.

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.

These are some answers to the Week 285, 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 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 1: No Connection

You are given a list of routes, @routes.

Write a script to find the destination with no further outgoing connection.

Example 1

Input: @routes = (["B","C"], ["D","B"], ["C","A"])
Output: "A"

"D" -> "B" -> "C" -> "A".
"B" -> "C" -> "A".
"C" -> "A".
"A".

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]

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.

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)

These are some answers to the Week 284, 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 1, 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: Relative Sort

You are given two list of integers, @list1 and @list2. The elements in the @list2 are distinct and also in the @list1.

Write a script to sort the elements in the @list1 such that the relative order of items in @list1 is same as in the @list2. Elements that is missing in @list2 should be placed at the end of @list1 in ascending order.

Example 1

Input: @list1 = (2, 3, 9, 3, 1, 4, 6, 7, 2, 8, 5)
       @list2 = (2, 1, 4, 3, 5, 6)
Ouput: (2, 2, 1, 4, 3, 3, 5, 6, 7, 8, 9)

Example 2

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

Here I share my personal favourite core enhancements in Perl v5.40.

https://theweeklychallenge.org/blog/what-is-new-in-perl

Just Graham and Philippe this time.

We talked about HTTPS in core, and some ideas about it, while the CPAN Security Group is preparing some proposals. Today was the deadline for releasing 5.41.1, but we don’t have volunteers yet, so Graham said he would do it sometime soon.

We also noted that we’ll need some volunteers for the next 10 or so development releases.

These are some answers to the Week 284, 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 September 1, 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: Lucky Integer

You are given an array of integers, @ints.

Write a script to find the lucky integer if found otherwise return -1. If there are more than one then return the largest.

A lucky integer is an integer that has a frequency in the array equal to its value.

Example 1

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

Example 2

Input: @ints = (1, 2, 2, 3, 3, 3)
Output: 3

Example 3

Wir freuen uns, die Veröffentlichung von OTOBO 11 bekannt zu geben! Die neueste Version der beliebten Open-Source-Ticketsystem-Software bringt zahlreiche Verbesserungen und neue Funktionen mit sich. Erfahren Sie mehr über die neuen Features und Änderungen auf OTOBO

Over the years that I have existed in four dimensions, I have come to accept that time is not a linear concept heading inexorably in one direction at a uniform rate. It didn't take an Einstein or Hawking to convince me either. Time is as malleable as the distortions applied by our consciousness, or imposed by those around us. Consider my youngest daughter's essay due to be handed in on Tuesday, a task assigned 4 months earlier. At 4,000 words, it represented roughly 6 words an hour allowing for eating, sleeping, work, weekend fun, and other essential time-devouring activities. Yet the "I have got plennnnty of time, chill, dad!" of a few months ago, has now turned into cries of despair, as she has to do an all nighter at her desk instead of being at some selfie-rich event critical to her mental well-being and social standing.

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]