This week in PSC (141) | 2024-03-21

This week, we:

  • Talked about some ideas for discussion at the upcoming PTS
  • Discussed the current blocked state of bleadperl following the 5.39.9 release and how to unblock it
  • Finished reviewing the release blocker bugs
  • Discussed how MetaCPAN should better handle perl releases and permissions

# Perl Weekly Challenge 275: Replace Digits

These are some answers to the Week 275, Task 2, of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Task 2: Replace Digits

You are given an alphanumeric string, $str, where each character is either a letter or a digit.

Write a script to replace each digit in the given string with the value of the previous letter plus (digit) places.

Example 1

Input: $str = 'a1c1e1'
Ouput: 'abcdef'

shift('a', 1) => 'b'
shift('c', 1) => 'd'
shift('e', 1) => 'f'

Example 2

Perl & Raku Conference 2024 to Host a Science Track!

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: ...

My 2023 in Perl

2023 was a rather productive year for me on CPAN. Aided by taking some time off I managed to release a whopping 18 new modules.

Passwords

Half of my new modules were related to my password framework Crypt::Passphrase. To be honest most of them are either small (± 100 LOC) glue two or three other pieces of code together. And then there was Crypt::HSM, a PKCS11 interface (to use cryptographic hardware without exposing cryptographic keys) that was probably more work (2600 LOC of XS) than the others combined.

Most of this was with the aim to add peppering support to Crypt::Passphrase, a subject extensive enough that I should probably dedicate a separate blogpost to it.

This week in PSC (140) | 2024-03-14

This week, we discussed:

  • Further look down open bugs to tag some as being release-blocker
  • Do we want to revert PR21915? - discussed in its own email thread
  • Thought of a couple of issues to discuss with the wider group at the upcoming PTS
    • How to handle “important author is AWOL” for upstream CPAN issues
    • How to not break CPAN tests when adding new warnings to core

Perl Weekly Challenge 253: Split Strings

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

Live streaming the release of Perl 5.39.7

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.

Never matching: everybody is doing it wrong

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.

This week in PSC (139) | 2024-03-07

Just Paul and Philippe this week:

  • Paul volunteers to do the 5.39.9 release. We still need people for .10 and 5.40. The .10 release will be timed around PTS - so maybe we could do something “live” at the summit?
  • Mailing list was otherwise quiet so there weren’t many issues to discuss.

In absence of many other pressing issues, we spent some time thinking ahead to large-scale development work that might take place in the 5.41 series. We talked about “hooks” as a potential long-term thought to making a more powerful Magic-like structure, for implementing new features, attributes, etc..

Step Counter (Advent of Code 2023/21)

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.

Perl Weekly Challenge 248: Submatrix Sum

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

Migrating from DBD::mysql to DBD::MariaDB

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.

This week in PSC (138) | 2024-02-28

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

Brain Memory Management

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

It's the Twelve Days of Dancer, 2023 edition!

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

Perl Weekly Challenge 247: Most Frequent Letter Pair

These are some answers to the Week 247, 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 17, 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 2: Most Frequent Letter Pair

You are given a string S of lower case letters 'a'..'z'.

Write a script that finds the pair of consecutive letters in S that appears most frequently. If there is more than one such pair, chose the one that is the lexicographically first.

Example 1

Input: $s = 'abcdbca'
Output: 'bc'

'bc' appears twice in `$s`

Example 2

This week in PSC (136) | 2024-02-15

  • 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.

System Thinking

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.

Is Perl a write only language?

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.

Perl Weekly Challenge 274: Goat Latin

These are some answers to the Week 274, 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 23, 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: Goat Latin

You are given a sentence, $sentance.

Write a script to convert the given sentence to Goat Latin, a made up language similar to Pig Latin.

Rules for Goat Latin:

1) If a word begins with a vowel ("a", "e", "i", "o", "u"), append "ma" to the end of the word. 2) If a word begins with consonant i.e. not a vowel, remove first letter and append it to the end then add "ma". 3) Add letter "a" to the end of first word in the sentence, "aa" to the second word, etc etc.

Example 1

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