These are some answers to the Week 287, 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 22, 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: Strong Password

You are given a string, $str.

Write a program to return the minimum number of steps required to make the given string very strong password. If it is already strong then return 0.

Criteria:

- It must have at least 6 characters.
- It must contain at least one lowercase letter, at least one upper case letter and at least one digit.
- It shouldn't contain 3 repeating characters in a row.

Following can be considered as one step:

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]

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

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.

These are some answers to the Week 286, 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 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 2: Order Game

You are given an array of integers, @ints, whose length is a power of 2.

Write a script to play the order game (min and max) and return the last element.

Example 1

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.

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.

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

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)

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

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.

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.

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.

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

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]

The Weekly Challenge 270/2

In the week 270, the second task was really interesting and difficult. Here’s a slightly reformulated version:

We’re given an array of positive integers @ints and two additional integers, $x and $y. We can apply any sequence of the following two operations: 1. Increment one element of @ints. 2. Increment two elements of @ints. The cost of each application of operation 1 is $x, the cost of operation 2 is $y. What’s the minimal cost of a sequence of operations that makes all the elements of @ints equal?

Why do I say it was difficult? I compared all the Perl and Raku solutions I could find in the GitHub repository and none of them gave the same results as mine. It took me several days to find an algorithm that would answer the tricky inputs I generated with a pen and paper, and one more day to optimise it to find the solutions in a reasonable time.

Last year at the Perl Toolchain Summit (PTS) in Lyon, I left three draft pull requests: one about the class declaration introduced in Perl 5.37, one about the PAUSE on docker, and one about multifactor authentication. I wanted to brush them up and ask Andreas König to merge some, but which should I prioritize this year?