blogs.perl.org

Back to the usual three of us

• Further chats on allowing a subsequent use VERSION of the same value as is already prevailing

• We continued going through the bug list to tag release blockers

I am very pleased to announce that the 2024 Perl & Raku Conference Planning Committee (TPRC) is moving forward with the addition of a new track that targets academic, governmental, and industrial STEM applications. It will strive to be organized as a traditional science conference track; meaning the talks will be based on paper and poster submissions. (more on this in a future announcement!)

The decision by the TPRC Planning Committee is the result of an overwhelmingly positive response to the Science Track Survey that was held late in 2023. Everyone involved in organizing the survey deeply appreciates those who filled out the survey or shared it with others.

The track is being organized in tight cooperation with the TPRC, by the Science Perl Committee (SPC); a separately organized group of Perl and STEM enthusiasts that anyone of good will is welcome to join.

What to expect now: ...

These are some answers to the Week 273, 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 June 16, 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: B After A

You are given a string, $str.

Write a script to return true if there is at least one b, and no a appears after the first b.

Example 1

Input: $str = "aabb"
Output: true

Example 2

Input: $str = "abab"
Output: false

Example 3

Input: $str = "aaa"
Output: false

I missed last year but in 2024 I'm doing a dev release of Perl again. This time it is version 5.39.7.
And again, you can watch it live on Saturday 20th of January on Twitch.

Paul was away this week.

• we talked about the hiccups that PAUSE seems to have been through
• we discussed further changes to the use VERSION behaviour (warnings)
• and we started going through the bug list to tag release blockers

Well, not actually wrong, just slow. But the exaggeration makes a punchier headline, you’ll admit.

This comes up when an interface takes a pattern to match things against. Sometimes you have some reason to want this match to always fail, so you want to pass a pattern which will never match. The customary way of doing this is to pass qr/(?!)/. There is a problem with that, though.

I’m not talking here about the fact that if possible, you really don’t want to pass an actual qr object. We’ve already covered that. It was a surprising enough discovery that I’ll take this opportunity to signal-boost that while we’re here, but this article is not about that.

The Task

We’re given a grid with obstacles, we’re supposed to count all the reachable plots in the grid in a given number of steps (we can only move one plot at a time horizontally or vertically).

The sample input looks like this:

...........
.....###.#.
.###.##..#.
..#.#...#..
....#.#....
.##..S####.
.##..#...#.
.......##..
.##.#.####.
.##..##.##.
...........

where S is the starting position.

These are some answers to the Week 248, 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 December 24, 2023, 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: Submatrix Sum

You are given a NxM matrix A of integers.

Write a script to construct a (N-1)x(M-1) matrix B having elements that are the sum over the 2x2 submatrices of A,

b[i,k] = a[i,k] + a[i,k+1] + a[i+1,k] + a[i+1,k+1]

Example 1

• working out a timeline of what should go in to 5.39.8, 5.39.9, and what to defer to 5.41
• draft tests+docs received from Martijn Lievaart (“M4”) for a logical xor (^^) operator
• the responses saying no to adding Data::Printer in core that it doesn’t seem like it would be popular
• some potential new sprintf format templates:
  • a float template that produces the shortest string that represents the exact float (similar to what Math::Ryu does),
  • a %q to access B::perlstring/quotemeta or something similar
• the realisation that, some months ago, Mark Gardner had volunteered to work on the SSL-in-core project, and we haven’t heard from them since.

DBD::mysql has long provided the interface to connect to the MySQL database from Perl code. But as old as it is, it was implemented with some critical bugs that cannot simply be corrected without breaking mountains of existing code relying on those bugs. For this same reason, though DBD::MariaDB corrects these bugs, care must be taken when migrating existing code to avoid subtle breakage.

This blog post is far too short to explain Unicode and encodings like UTF-8; for anyone seeking a more solid grasp on the concepts, I recommend a read through The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) by Joel Spolsky.

My next dev article about the important concept of cognitive load of code and how to manage it.

The 2023 Dancer Advent Calendar, the Twelve Days of Dancer is up and running! We hope you'll enjoy this year's version - there's a lot of fun and practical gifts to be found there.

Hot on the heels of our earlier gift (Dancer2 1.1.0) come two more plugin releases, Dancer2::Plugin::Cache::CHI and Dancer2::Plugin::Syntax::GetPost.

Enjoy! Let us know what you think. Happy holidays to all! (and now it is time for this Dancer to enjoy a long winter's nap)

Jason/CromeDome

All three of us returned.

We only had one issue to discuss, the pressing matter of how to handle lexical unimports, builtin version bundles, the integration with use VERSION, and various related topics.

It’s complicated. We’ve been putting together a longer mail on the subject and that will come out as its own thread soon.

These are some answers to the Week 273, 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 June 16, 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: Percentage of Character

You are given a string, $str and a character $char.

Write a script to return the percentage, nearest whole, of given character in the given string.

Example 1

Input: $str = "perl", $char = "e"
Output: 25

Example 2

Input: $str = "java", $char = "a"
Output: 50

Example 3

Input: $str = "python", $char = "m"
Output: 0

Example 4

I started to also post on dev.to and will post there mostly about topics larger than Perl : psychology of programming, software engineering and alike.

I am sick and tired of hearing this, so let's put it this to the test. Assume you know little of Perl, or any programming language for that matter. Can you parse the code?

https://chrisarg.github.io/Killing-It-with-PERL/2023/12/06/Is-Perl-a-write-only-language.html

I hope the piece above is the first in a series to convince people to consider the reality before passing judgement. It was inspired by one of our research analysts discovering Perl and awk to simplify their lives when cleaning data.

Three Perl releases have been published this past week, containing patches for security issues CVE-2023-47038 and CVE-2023-47039. This kept us busy for the past few weeks (explaining the somewhat thinner recent updates).

• Paul will publish a post-mortem on the recent releases, looking at what went wrong and some thoughts on how to improve it so those don’t happen again
• We discussed a plan to improve documentation of the security disclosure process
• We took note of what projects we have in flight (e.g. PPCs being implemented) and may find a way to keep that list published and updated

These are some answers to the Week 272, 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 June 9, 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: String Score

You are given a string, $str.

Write a script to return the score of the given string.

The score of a string is defined as the sum of the absolute difference between the ASCII values of adjacent characters.

Example 1

Season's Greetings, Perl!

I've spent almost all of my time since my [last post here]( https://blogs.perl.org/users/ingy_dot_net/2023/05/perl-toolchain-synergy.html) working on a new programming language, YAMLScript.

It's working now and I've decided a do a [2023 Advent YAMLScript Blog]( https://yamlscript.org/posts/advent-2023/index/) for it. The blog started last Friday and will continue (at least) until December 24th.

I encourage you to follow along. At some point this month YAMLScript modules will become available for CPAN and Raku and many other languages. I also encourage you to try writing an [Advent of Code 2023]( https://adventofcode.com/) solution in YAMLScript, if you are playing along with AoC this year.

All the Best, Ingy döt Net

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