These are some answers to the Week 183 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Task 1: Unique Array

You are given list of arrayrefs.

Write a script to remove the duplicate arrayrefs from the given list.

Example 1

Input: @list = ([1,2], [3,4], [5,6], [1,2])
Output: ([1,2], [3,4], [5,6])

Example 2

Input: @list = ([9,1], [3,7], [2,5], [2,5])
Output: ([9, 1], [3,7], [2,5])

Unique Array in Raku

The Raku solution is essentially a one-liner (more than one line because of the tests). We convert the sub-arrays into strings and use the unique built-in routine to remove duplicates.

Sooner or later any programmer, writing in any language, will run across something like this Perl warning: Subroutine foo redefined. This is telling you that somehow, somewhere, you tried to create two subroutines with the same name.

Tracking this down can be tricky, and remediation equally so. The possibilities include:

• If one of your own subroutines is involved, you can rename it.
• If an imported subroutine that you do not need is involved, you can just not import it. This, of course, involves figuring out which imports you do need. The use of default import lists can make tracking this one down tricky.
• You can use Importer to import a subroutine under a different name.
• You can ignore the import mechanism and populate the symbol table yourself with something like BEGIN { require Some::Module; *foo = \&Some::Module::bar; }, after which bar() calls Some::Module::foo().

This is my entry for

The Weekly Challenge, week 127

Task 1, "Disjoint Sets" was basically something I've done before somewhere else. In fact, what I'm using is overkill for just determining if two sets intersect. I imagine most people would probably use the FAQ answer. However, I'm a fan of what cardinal LanX of Perl Monks fame was trying to do in making set intersection a more "organic" operation. I don't know how much those ideas developed, however, so I'll be looking at the other solutions to see if there's anything new.

I actually did use my perlmonks code on real problem a few years ago, in modified form. It does the trick pretty quickly compared to other approaches. Thanks perl hashing!

You can find my code for Task #1 here.

Object::Pad Yuki Kimoto's 2021-08-25(I fix this entry because default internal data structure is array reference, not hash reference).

This time is default internal data structure of the object.

Default internal data structure of the Object::Pad is array reference.

These are some answers to the Week 182 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few of days from now (on Sept. 18, 2022 at 23:59). This blog post offers some solutions to this challenge, please don’t read on if you intend to complete the challenge on your own.

Task 1: Max Index

You are given a list of integers.

Write a script to find the index of the first biggest number in the list.

Example:

Input: @n = (5, 2, 9, 1, 7, 6)
Output: 2 (as 3rd element in the list is the biggest number)

Input: @n = (4, 2, 3, 1, 5, 0)
Output: 4 (as 5th element in the list is the biggest number)

Max Index in Raku

Never been so busy ...

The guilt is killing me every time I delay the monthly report. I finally found time to get this out on 22nd day of the month where I would do that on the very first day of the month in the past.

Life can be challenging at times, balancing personal and professional aspect can be difficult, I must confess.

In all of these up and down, I have to keep myself motivated and find ways to stay happy.

I try to avoid negative thoughts coming on my way and stay positive.

Have you heard that they are finally putting together a proposal to add a clean modern OO system into the core of Perl?

If you haven’t, I strongly encourage you to look over the RFC for Corinna, or at least watch Ovid’s excellent presentation on the project.

It’s reassuring that the list of contributors to the proposed design includes some of the most highly respected names in the Perl community, many of whom have previously taken one (or more!) tilts at this particular object-oriented windmill.

Indeed, over the past two decades I too have repeatedly attempted to design and prototype richer and more robust OO systems for Perl, starting way back in the previous millennium with a brief stint as the maintainer of Class::Struct, and continuing on though the release of modules such as Class::Std, Class::Delegation, and most recently: Dios.

One of the changes to Perl that we're considering on p5p (the perl5-porters mailing list) is the removal of taint support. The first step towards that is to add a Configure option that lets you build a Perl without taint support.

In this post I'll explain what we're considering, and why. The purpose of this post is to let everyone beyond p5p know about this, and give you a chance to comment.

These are some answers to the Week 181 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few of days from now (on Sept. 11, 2022 at 23:59). This blog post offers some solutions to this challenge, please don’t read on if you intend to complete the challenge on your own.

Task 1: Sentence Order

You are given a paragraph.

Write a script to order each sentence alphanumerically and print the whole paragraph.

Example:

Again another week where I solve one answer and punt on another.

TWC Task #1, Happy Women Day

jaredor submission for Task #1

Well, "solve" may be a strong word for what I did with this problem, at least for my programming conscience. The problem statement was simple, but had no requirements for an acceptable solution other than what you could infer from the example solution in the problem statement. However I did give not one, but two solutions, so that's not totally lazy, even if each, on its own, is lazy, right?

--lazy solution

Since my last post I wanted to take my EV charge calculator script and convert it into a web form. In this post I breakdown how I migrated the script to a Dancer2 web app.

Just a minor note for those readers who may not be aware, Dancer2 is a "lightweight web-framework for Perl" as described in Dancer2 documentation and can be similar in comparison to Ruby Sinatra and Python Flask.

I started by creating a new project folder with the dancer2 program ( # please note that I am working on a Windows PC and on a linux OS the program would just be named dancer2 )

dancer2.bat -a EVCalc

I then copy over the files inside this directory to my project repository as shown in this commit and moved all the scripts to the bin directory as shown in this commit

I wrote a script to covert the electric rate csv file into a module and added all the calculation code in the main project module. All the html markup is stored in this template file and I sprinkled some CSS which renders a page similar to the screenshot below after submitting some data for calculating the charge of an EV :

Thank you for your time, I hope you enjoyed my post.

On github at https://github.com/ronsavage/SQL you will find a repo of SQL stuff created by Jonathan Leffler.

I recently added some files for SQL 2003 and SQL 2016, created by Domingo Alvarez Duarte.

Specifically, look for:
o sql-2003-2.ebnf
o sql-2003-2.ebnf.readme
o sql-2003-2-railroad-diagrams.xhtml
o sql-2016.ebnf
o sql-2016.ebnf.readme
o sql-2016-railroad-diagrams.xhtml

I'd suggest downloading the *.xhtml files and viewing them locally, rather than hammering the on-line convertor mentioned in the readme files, which accepts *.ebnf files and displays these railroad diagrams.

And that begs the question: Is there any Perl code which converts a grammar into a railroad diagram?

These are some answers to the Week 180 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few of days from now (on Sept. 4, 2022 at 23:59). This blog post offers some solutions to this challenge, please don’t read on if you intend to complete the challenge on your own.

Task 1: First Unique Character

You are given a string, $s.

Write a script to find out the first unique character in the given string and print its index (0-based).

Example 1

Input: $s = "Perl Weekly Challenge"
Output: 0 as 'P' is the first unique character

Example 2

Input: $s = "Long Live Perl"
Output: 1 as 'o' is the first unique character

First Unique Character in Raku

JIT blogging

I'm always doing other things and then Sunday comes and I start thinking, "How much time do I have before it's midnight in London?"

When "The Perl Challenge" first started, I was happy to just ponder the problems. Then came the pandemic and I thought that I would use some of my then copious free time to contribute. Then time got not-so-copious. And more people started contributing to TWC, some people much more talented than me, it turns out.

So I'll take a stab at things when I can and I'll still try to write a stand-alone script the way (I wish) I would at work, but my threatened laxness in writing things up will be more of a promise: Light banter to cast a veneer of confidence on the correctness of my results, anything else is extra.

TWC Task #1, Ugly Numbers

Higher Order Perl, Chapter 6, "Infinite Streams," Section 6.4, "The Hamming Problem"

It's very slow if you have more than a few thousand keys in memcached. Not an unusual use case I think? I've got a fix here, which appears to DTRT: https://rt.cpan.org/Ticket/Display.html?id=138133. Maybe? I didn't spend too long looking at memcached's low level wire protocol.

The patch passes all the module's current tests and works for us. It took our CPU load from being pegged at 75% all of the time to being idle. So, if you're using Cache::Memcached, and the ->stats method (which isn't in the XS version of the module) then you might want this patch.

On that note - who is maintaining Cache::Memcached? The last release was in 2012. This isn't a high river module, but any app of significant size or age is *probably* using it and if they're using the ->stats method then ... Sure there's the ::Fast version, but I suspect this version is in a lot of places.

So if you know someone who knows someone who can prod the current maintainers then please point them at this post/patch. If you're using Cache::Memcached then perhaps try out this patch as well.

Today I have wandered on the famous academic paper archive and suddenly a thought popped into my mind - use Perl as the keyword in searching.

Computer science papers with "Perl" in the title
https://arxiv.org/search/advanced?advanced=1&terms-0-operator=AND&terms-0-term=Perl&terms-0-field=title&classification-computer_science=y (8*)

Computer science papers with "Lisp" in the title
https://arxiv.org/search/advanced?advanced=1&terms-0-operator=AND&terms-0-term=Lisp&terms-0-field=title&classification-computer_science=y (12**)

Computer science papers with "Ruby" in the title
https://arxiv.org/search/advanced?advanced=1&terms-0-operator=AND&terms-0-term=Ruby&terms-0-field=title&classification-computer_science=y (6***)

Computer science papers with "Julia" in the title
https://arxiv.org/search/advanced?advanced=&terms-0-term=Julia&terms-0-field=title&classification-computer_science=y (53 ****)

For Haskell: ~50

For Java: ~249

For Python: ~357

For Perl Data Language (PDL): 0

These are some answers to the Week 179 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few of days from now (on Aug. 28, 2022 at 23:59). This blog post offers some solutions to this challenge, please don’t read on if you intend to complete the challenge on your own.

Task 1: Ordinal Number Spelling

You are given a positive number, $n.

Write a script to spell the ordinal number.

For example,

11 => eleventh
62 => sixty-second
99 => ninety-ninth

Hum, this task is not very interesting, since it has more to do with English than with computer science. I’m not going to enumerate dozens of numeral or ordinal English names. So, contrary to what I usually do, I’ll use an off-the-shelf module to complete this task.

Ordinal Number Spelling in Raku

Look, that's why there's rules, understand? So that you think before you break 'em. — Terry Pratchett, in Thief of Time.

A couple installments into this series of blog posts, I realized an introduction to Perl warnings would be appropriate, with some words on how to turn them off, and why you probably do not want to. Yes, this should have been the first post in the series, but I didn't know it would actually be a series, and, well, maybe better late than never.

The Perl compiler/interpreter can emit warnings when it finds things that may indicate a problem with the code. These are not (yet) enabled by default, but experience has shown that enabling them can highlight conceptual and logic errors.

Released Giblog 2.0. GIblog is a tool to create your web site easily.

Giblog 2.0 Release Announcement

Giblog 2.0 is released at 2021-7-24. serve command and publish command is added.

Giblog 2.0 Release Announcement

Giblog Document

Giblog Document in CPAN.

Giblog Document

Giblog Movie

I explain how to create your website using Giblog and Perl by live coding. Giblog is a Perl module to create web sites. If you see this movie, you can create your web site using Giblog and Perl(although you need some Linux knowledge).

Have a look at the CPAN Testers reports for two TRIAL releases of the same module, one from 2 days ago, the other a little over 3 years ago:

• Matrix for Text-Tabs+Wrap 2021.0712-TRIAL

• Matrix for Text-Tabs+Wrap 2018.0419-TRIAL

  Note: the current version of Perl in late April 2018 was 5.26.2, so all reports on more recent perls came in (long) after the initial testing which I’m interested here. The relevant part of the page is therefore the part from 5.26.2 on down.

Last time, reports started coming in within hours of the release; over 60% of the picture was there within a day; some 85% after 2 days; and the first wave of reports lasted a week.

This time, it took almost a day to even start getting reports, and the diversity has been much lower. 3 days in, reports are still absent for many platforms: