This week we have a very simple challenge! Again due to time, I just did the first challenge this week, but I have an idea of how I'd solve the second and I'll compare with the way others implemented it.

Anyway, to the challenge. The goal is to find the 3rd smallest element of a matrix. The simplest way is simply to flatten, sort, and pick the element. There might be absolutely more performant ways to do it, such as scanning the entire matrix once and keeping a list of the lowest three as you iterate, but this is a case where I feel that it's simply not worth it. One pass to flatten and one sort isn't worth all the extra implementation complexity. I do look forward to seeing any solutions including that technique though.

Here's my code:

These are some answers to the Week 253, 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 January 28, 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: Weakest Row

You are given an m x n binary matrix i.e. only 0 and 1 where 1 always appear before 0.

A row i is weaker than a row j if one of the following is true:

a) The number of 1s in row i is less than the number of 1s in row j.

b) Both rows have the same number of 1 and i < j.

Write a script to return the order of rows from weakest to strongest.

Example 1

Env::Dot

In the category of “scratching my itch”.

Background

An app’s config is everything that is likely to vary between deploys (staging, production, developer environments, etc). The Twelve-Factor App

Storing the often changing parts of configuration in environment variables is one of the principles of The Twelve-Factor App.

From this principle follows the need to store those environment variables and their values in an easily accessible way. Hence, every developer maintains his or her own project specific .env files next to the project files in the same directory where they are used, for instance, when running locally or testing locally.

Yet Another Dotenv Solution

As if we didn’t have these enough already…

What is different with this one, except the name Env::Dot?

Flexibility in input

All three of us met, having skipped last week.

There wasn’t much to talk about because code freeze ahead of 5.38 is in effect, so there isn’t much going on.

• We talked further about the upcoming deprecations scheduled for 5.38.0 (smartmatch, tick-as-package-separator), and concluded that we remain committed to keeping them deprecated on the current schedule.

• Next week’s meeting will be in person in the French city of Lyon.

Hi everybody!

Just one solution to the first task in the weekly challenge this week, and it's a different type. I didn't have time to do any more, and this solution might not be the most efficient or cleanest, but it looks reasonably good to me.

The goal is to find any words which contain all the letters of the car registration number. I assume this would be to find a nickname for your car based on its registration number. In the examples, all of the words are lower-case, so I just assume that my inputs are lower-case. This week I used a few language features that I haven't used in previous challenges, like loop labels, POSIX classes, and a variable regex. As usual, the first argument to the script (without the space in the rego in the examples) is the registration and the rest of the arguments are the words to match it to.

Here's the code: #!/usr/bin/perl

These are some answers to the Week 253, 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 January 28, 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: Split Strings

You are given an array of strings and a character separator.

Write a script to return all words separated by the given character excluding empty string.

Example 1

Input: @words = ("one.two.three","four.five","six")
       $separator = "."
Output: "one","two","three","four","five","six"

Example 2

Input: @words = ("$perl$$", "$$raku$")
       $separator = "$"
Output: "perl","raku"

Split Strings in Raku

Near the Christmas in 2022, I played a data engineering challenge called "Hanukkah of Data 5783". You can find it on https://hanukkah.bluebird.sh/5783 . Players can download data of either .CSV, .JSON or .SQLITE format.

The first* task is like this:

... And their phone number was their last name spelled out. I didn’t know what that meant, but apparently before there were smartphones, people had to remember phone numbers or write them down. If you wanted a phone number that was easy-to-remember, you could get a number that spelled something using the letters printed on the phone buttons: like 2 has “ABC”, and 3 “DEF”, etc."

* There is a "zeroth" task on the calendar year.

I didn't mind perish my skill on SQL, but these kinds of things immediately I thought of Perl, maybe there would be a subroutine like this:

The other day I was working on yet another side project. Almost immediately I got side tracked. Does that make the new project a side side project?

What shiny bobble or cool new tech got my attention you ask? It wasn't $buzzword, or $fancy_tech. Nawe, nothing that resumé worthy. Instead, I decided to see what a MVP for a REST API would look like in using Catalyst. Look ma, no extra modules! _{Except a JSON one, but I don't count it since Catalyst also uses a JSON module.}

NOTE: If you are trying to be productive, you probably want to just use Catalyst::Action::REST instead of rolling your own. That's what I've used at work with great success.

Other than generating the scripts I went ahead and hand wrote out everything else and was pleasantly surprised. There was so little code that I went ahead and retyped the only three modules needed here. Apologies if there's a typo.

Onward to the MVP!

Paul, Philippe, and Ricardo had our mostly-weekly Zoom call today.

We began by discussing last week, when Pete K from TPRF joined us and we talked about what TPRF could do to help p5p. (Main topics then, which didn’t get any firm action items, were support for critical infrastructure and services and bounties for implementation of PPCs.)

Most of our time this week was spent on the upcoming v5.38.0 release, especially what might be blocking it. (Notable: two new deprecation warnings added in the last two releases — smartmatch, and tick as package separator.)

We discussed strategies used by other languages to make things more attractive for developers, like batteries included. We didn’t end up with any plan of action from this.

In a few weeks, we’ll all be in one place, and look forward to looking carefully at the color of Chartreuse.

These are some answers to the Week 252, 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 January 21, 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: Unique Sum Zero

You are given an integer, $n.

Write a script to find an array containing $n unique integers such that they add up to zero.

Example 1

Input: $n = 5
Output: (-7, -1, 1, 3, 4)

Two other possible solutions could be as below:
(-5, -1, 1, 2, 3) and (-3, -1, 2, -2, 4).

Example 2

The official document provided by Web::Scraper is quite clear. I copied the style and comments and made up a script :

Hi ! Everyone, I am back here to ask environmental issue.
When I ran the following CGI.pm testing script before placing at /var/www/cgi-bin, but it is still at /home/mkido/bin. Perl script ran successfully at the Terminal, and replied back the OUTPUT below there.

Perl Script, check.pl
#!/usr/bin/env perl
use strict;
use warnings;
use CGI;

my $q = CGI->new;
print $q->header();
print "OK";

===================
OUTPUT
mkido@localhost$check.pl [Enter to run it.]
Content-Type: text/html; charset=ISO-8859-1

OK
mkido@localhost$

This output result evoked my recognition. Is this Rocky 9.1 Web Server running to provide charset=ISO-8859-1 ?? I want to set all replies from the Server to charset=UTF-8. The httpd.conf is already set to charset=UTF-8. Is there any other setting adjustment somewhere in environmental configuration on my server to change from charset=ISO-8859-1 to charset=UTF-8 ?? Thanks, thanks.

These are some answers to the Week 252, 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 January 21, 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: Special Numbers

You are given an array of integers, @ints.

Write a script to find the sum of the squares of all special elements of the given array.

An element $int[i] of @ints is called special if i divides n, i.e. n % i == 0, where n is the length of the given array. Also the array is 1-indexed for the task.

Example 1

Today, the popular Dark Sky weather API is shutting down. I did a little write-up for non-Perl devs on DEV.to, but I thought I'd post here a couple of potentially useful modules I released to CPAN recently. 

use Weather::WeatherKit;

my $wk = Weather::WeatherKit->new(
    team_id    => $apple_team_id,
    service_id => $weatherkit_service_id,
    key_id     => $key_id,
    key        => $private_key
);

my %report = $wk->get(
    lat      => 51.2,
    lon      => -1.8,
    dataSets => 'currentWeather'
);

Of course, this API is sort of free, as it requires an Apple developer account. If you don't have one and don't want to get one, there are some alternative APIs, but for the purposes of this post I'll stick to 7Timer, via Weather::Astro7Timer. Even simpler, as it does not need authentication:

Destination: Graph
Date of Latest Release: Feb 12, 2023
Distribution: Graph
Module version: 0.9726
Main Contributors: Jarkko Hietaniemi (JHI)
Current Maintainer: Neil Bowers (NEILB)
License: [perl_5]

Long time ago I claimed in front of a friend I would write a short introduction to graph theory, but I had been not able to figure out where I should start. Neither I would try today. The mathematical objects graphs, or the abstract data structures graphs, are full of interesting behaviors being studied in the discrete math subdiscipline graph theory. The CPAN module Graph is designed to empower Perl programmers doodle with undirected graphs and directed graphs (and also multigraphs and hypergraphs - not going to visit these functionalities here).

I'm back this week with PWC #210. Last week I was very busy and spent a long time reviewing other peoples' far more efficient solutions to #208, so I didn't get to doing any solutions for #209. The usual disclaimer about this could contain spoilers, so if you're trying to solve the challenge yourself you may want to skip this post for now. So let's get right into this.

Kill And Win

For this challenge I decided to use some of the tools I learned about in the solutions other people submitted for #208, especially the ways hashes can make the process more efficient. The goal is to find the number in the list where you can delete the most points by deleting the number and its adjacent numbers plus and minus one. You get to count each number however many times it appears in the list.

These are some answers to the Week 251, 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 January 14, 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: Lucky Number

You are given a m x n matrix of distinct numbers.

Write a script to return the lucky number, if there is one, or -1 if not.

A lucky number is an element of the matrix such that it is the minimum element in its row and maximum in its column.

Example 1

Consider a simple module like this:

Topics discussed:

• Bug reporting by email: we commit to nothing as an organisation. Some would-be submitters of issues don’t want to use GitHub. They can just send an email to perl5-porters and hope that some helpful soul will copy-paste to GitHub. We encourage the conventional use of GitHub.
• On the topic email bug reports, it’s likely time to deprecate perlbug as a way to send bug reports. It could be updated to point the user to GitHub, and to print perl -V output (etc.) to copy and paste. We should also have a better set of templates for issues on GitHub.
• The segfaults on feature-class and refaliasing won’t be fixed before 5.38, and should just be documented as “known bugs”
• After we discussed renaming RFC to PPC, the general sentiment seemed to be “in favor”, so we’re going to make the rename
• Rik volunteered to release 5.38, we still need a release manager for 5.37.11
• Some discussions about preparing the Perl Toolchain Summit plans (which will host the first ever in-person PSC meeting)