This week in PSC (156) | 2024-08-15

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]

Perl Weekly Challenge 285: Making Change

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.

TWC 277: Strength Uncombined

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

How to use perl v5.40's boolean builtins in Mojo::Pg queries

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.

This week in PSC (155) | 2024-08-08

Just Graham and Aristotle this time.

  • Discussed tracking perl authorized releasers updates and storing historical data
  • Dual-Life modules need some cleanup to get a more normal release process that can be done more regularly. Cleanup has been done on Storable.
  • Time::HiRes by default doesn’t seem terrible, if possible
  • X509 in core could make sense as part of a more complete interface to OpenSSL
  • Discussion about how it would be possible to have support for Markdown or other new Pod extensions in a more backwards compatible way. Possibly a way to define alternate formats for =begin/=end sections.

[P5P posting of this summary]

Using Coro and AnyEvent Interactively

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.

Perl Weekly Challenge 277: Strong Pair

These are some answers to the Week 277, 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 July 14, 2024, known in France as Bastille Day, 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: Strong Pair

You are given an array of integers, @ints.

Write a script to return the count of all strong pairs in the given array.

A pair of integers x and y is called strong pair if it satisfies: 0 < |x - y| < min(x, y).

Example 1

Input: @ints = (1, 2, 3, 4, 5)
Ouput: 4

Strong Pairs: (2, 3), (3, 4), (3, 5), (4, 5)

Example 2

Sailing the Seven YAPCs


[This is my seventh YAPC / TPC.  If you like, you can read about my other YAPC experiences: YAPC 2011, YAPC 2013, YAPC 2014, YAPC 2015, YAPC 2016, YAPC 2018.]


Well, after taking a very long break inspired (to understate it a bit) by the pandemic, I’m back to attending in-person Perl events with my seventh YAPC.  Or, The Perl Conference, I suppose, but it still feels like YAPC to me.  As per usual, here are some reflections.

This week in PSC (154) | 2024-08-01

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

Repository of examples using Perl and Assembly together

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.

Today I learned... #1: variable scoping in if-else blocks

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)

Perl Weekly Challenge 276: Complete Day

These are some answers to the Week 276, 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 July 7, 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: Complete Day

You are given an array of integers, @hours.

Write a script to return the number of pairs that forms a complete day.

A complete day is defined as a time duration that is an exact multiple of 24 hours.

Example 1

Input: @hours = (12, 12, 30, 24, 24)
Output: 2

Pair 1: (12, 12)
Pair 2: (24, 24)

Example 2

This week in PSC (153) | 2024-07-25

After over a month without a PSC meeting, this was the first meeting of the new, shiny PSC. Today, we:

  • welcomed Aristotle, and said goodbye to Paul
  • discussed the current projects in flight, the PPC process and the onboarding tasks (preparing for next year already!)
  • talked about POD, docstrings, and the Perl release process

Parallel Perl/C applications without tears using OpenMP: Controlling the OpenMP environment

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.

Justifying Embarrassing Errors.

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

Perl Weekly Challenge 285: No Connection

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".

What's new in Perl v5.40?

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

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

This week in PSC (152) | 2024-06-20

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.

Neuigkeiten: OTOBO 11 Veröffentlicht

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

Perl Weekly Challenge 284: Lucky Integer

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

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