blogs.perl.org

These are some answers to the Week 122 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a few days, on July 25, 2021 at 24:00. 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: Average of Stream

You are given a stream of numbers, @N.

Write a script to print the average of the stream at every point.

Example:

Input: @N = (10, 20, 30, 40, 50, 60, 70, 80, 90, ...)
Output:      10, 15, 20, 25, 30, 35, 40, 45, 50, ...

Average of first number is 10.
Average of first 2 numbers (10+20)/2 = 15
Average of first 3 numbers (10+20+30)/3 = 20
Average of first 4 numbers (10+20+30+40)/4 = 25 and so on.

If you want to challenge yourself on programming, especially on Perl and/or Raku, go to https://perlweeklychallenge.org, code the latest challenges, submit codes on-time (by GitHub or email).

---

Task 1 Prime Sum

What a dish for math geeks! Goldbach's conjecture is immediately recalled. I have chosen to print the answer first, than give the expression and explanation.

I was working on the completely fresh rewrite of perlmodules.net, when I decided I want to use WebSockets with this site.

So "innovations" started flowing through my mind in order to achieve WebSocketry, and ended-up deciding it would be very helpful if I could use ReactiveX on my Mojolicious site, in terms of size and neatness of the code, buglessness and maintainability.

This is how we ended up with RxPerl, a project I spent a lot of time to make it work well.

Now at version v0.16.0 on CPAN, it is a release candidate. I would like to ask anyone interested to take a look and see if they can find things they don't like about it, in advance of its proper v6.0.0 release which could happen late next week.

https://metacpan.org/pod/RxPerl

Thanks.

Today we will focus on a simple task: listing the files contained in a directory, sort them by modification time (see mtime and display the result in a JSON array.

We are gonna use Mojo::File for the file system part and Mojolicious::Lite to expose those data on a simple but effective JSON API.

These are some answers to the Week 121 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due on July 18, 2021 at 24:00. This blog post offers some solutions to this challenge, please don’t read on if you intend to complete the challenge on your own.

You are given integers 0 <= $m <= 255 and 1 <= $n <= 8.

Write a script to invert $n bit from the end of the binary representation of $m and print the decimal representation of the new binary number.

Example:

Time for another monthly report? Time just flies.

It was the most busiest month of the year 2020 for me. Of course, most of my spare time was dedicated to The Weekly Challenge. We, as a team, created record of 100+ contributions 4 weeks in a row. It was hectic and exhausting, I must admit.

With every passing week, the team is also growing. Team members are blogging more often. As of today, we have received 3000+ Perl contributions and 2000+ Raku contributions. For blogs, very soon we would cross 1000 mark, currently it stands at 940. Did I expect such response in the beginning? No, never dream of such support.

Encouraged by Gabor Szabo, I created my Patreon profile for the first time. I am overwhelmed by the support I have received so far. I would like to take this opportunitity to thank each and every supporters.

A little over a month ago I learned about the Perl Weekly Challenges. The site states the challenges are for any skill level. So, I went and took a look. After looking at the first challenge that week, I realized “any skill level” did not mean my skill level.

My skill level is pretty basic.

I can …

• open, read, and close text files and do simple manipulation of the data.
• add, subtract, multiply, and divide when it comes to math.
• tack on words or phrases to the beginnings or ends of strings okay with loops.
• write some basic regexen.
• even roll things randomly.
• do most of the above conditionally.

… that is about it.

I read the challenges and my mind is totally blank on where to start after…

I wish I could grasp the concepts in the Perl Weekly Challenges, especially the math. I have not taken a math class in over 30 years, and what math I remember is, as I said, pretty basic.

Oh, and one needs to be more than a little familiar with Git and GitHub to contribute, which I am not.

If you want to challenge yourself on programming, especially on Perl and/or Raku, go to https://perlweeklychallenge.org, code the latest challenges, submit codes on-time (by GitHub or email).

Continued from the discussion of Task 1.

Task 2 Largest Rectangle Histogram

I am not a narcissist; though some of my actions are narcissistic traits, it does not imply that there is yet another narcissist; I am motivating myself for a better self.

Back to the task. This look like a task testing our overall commanding of the language (especially when the bonus is also considered), not an algorithm-oriented task.

At the first sight, looking for the largest rectangle seems uneasy. My order of coding has been: Perl code, Python code, Java code (3 at a time because I got a day-off on Tuesday) and (after a few days) Lisp code. The following is my note during coding the Perl of the task, informally:

These are some answers to the Week 120 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days, on July 11, 2021). 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: Swap Odd/Even Bits

You are given a positive integer $N less than or equal to 255.

Write a script to swap the odd positioned bit with even positioned bit and print the decimal equivalent of the new binary representation.

Example:

Please follow the blog where I discuss the two tasks "Coins Sum" and "Largest Rectangle Histogram" of "The Weekly Challenge - 075".

https://perlweeklychallenge.org/blog/weekly-challenge-075

Prompted by a recent question on PerlMonks, I've been thinking a bit recently on marshalling and unmarshalling Perl objects. If you're happy using Data::Dumper's format, then it's trivial, but today we're looking at JSON.

If you just want to encode your objects as JSON, that's very easy. Just add a TO_JSON method to all your classes. This can be done in a role to eliminate duplication, and in most cases can be as simple as:

The difficulty comes in going the other direction.

You can see the results here.

The following is my reflection on those results and doesn't reflect anyone else's opinions. They may not even really be my opinions.

Who responded?

Some 85.9% respondents self identify as Perl programmers and 22.7% as Raku programmers, 33.2% as Software project leaders, and 30% as Business Owners.

Brand Values

In regards to brand values there is a huge gap between perception and expectation. I've cut off the long tail of "Other" responses for clarity, follow the link at the top to see them.

(The long titles overlap. The first 5 are Amateur, Passionate about helping software projects, Powered by Volunteers, Professional, Secretive)

(The long titles overlap. The first 5 are Passionate..., Powered by Volunteers, Professional, Servant Leadership, Supportive)

These are some answers to the Week 119 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days, on Independence Day (July 4, 2021). 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: Swap Nibbles

You are given a positive integer $N.

Write a script to swap the two nibbles of the binary representation of the given number and print the decimal number of the new binary representation.

A nibble is a four-bit aggregation, or half an octet.

To keep the task simple, we only allow integer less than or equal to 255.

Example:

If you want to challenge yourself on programming, especially on Perl and/or Raku, go to https://perlweeklychallenge.org, code the latest challenges, submit codes on-time (by GitHub or email).

Thanks for the volunteers, there are code Reviews on Perl/Raku; in addition, on each Monday, you can read the RECAP linking others' solutions and blogs; I often learn something from both RECAP and Perl Review.

One week to the end of August!

Alan J. Perlis said, “A language that doesn’t affect the way you think about programming, is not worth knowing.”

I would add a clause to it: unless it helps you earn your living...

Self Challenge

Making risky/improbable promises are usually looked down in Hong Kong, though some people do support the venturesome spirit (not quite for females, but – personal feelings). “Jump-in, jump-out” is not welcomed, as for my understanding to Hongkongers. (I actually stay on Internet more than in Hong Kong society.)

https://perlweeklychallenge.org/blog/weekly-challenge-074

As announced on TPF news the Marketing committee of TPF have been running a survey "to learn your responses to the ideas about branding, naming and the perceptions of the values concerning the Perl Foundation itself."

This survey will close in just a few hours, so if you have yet to give your feedback please do so asap!

P.s. Please join the more than 4,000 members of "Perl Programmers" on Facebook

These are some answers to the Week 118 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days (June 27, 2021). 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: Binary Palindrome

You are given a positive integer $N.

Write a script to find out if the binary representation of the given integer is Palindrome. Print 1 if it is otherwise 0.

Example:

Input: $N = 5
Output: 1 as binary representation of 5 is 101 which is Palindrome.

Input: $N = 4
Output: 0 as binary representation of 4 is 100 which is NOT Palindrome.

Binary Palindrome in Raku

If you want to challenge yourself on programming, especially on Perl and/or Raku, go to https://perlweeklychallenge.org, code the latest challenges, submit codes on-time (by GitHub or email).

Thanks for the volunteers, there are code Reviews on Perl/Raku; in addition, on each Monday, you can read the RECAP linking others' solutions and blogs; I often learn something from both RECAP and Perl Review.

Do tell me, if I am wrong or you strongly oppose my statements!

---

While the weekly challenge is fighting towards new record of number of submissions, I am starting my own programming adventure. Congratulations to CY Fung, she knows how to code in Python and Java now. I am going to submit guest solutions in these two languages for the coming challenges.

Task 1 Coins Sum

https://perlweeklychallenge.org/blog/weekly-challenge-073

Perl 7 has been announced as the next direction of Perl development. My previous blog post explored at a high level the risks and benefits of the announced direction, as well as those of a more incremental proposal. The primary and critical difference between these two approaches is the decision to change interpreter defaults in an incompatible manner; specifically, to have strict and warnings and possibly other features enabled by default for code that does not specify otherwise. I would like to explore each of the arguments presented for this design choice.

Optimizing For New

The primary benefit of changing the implicit defaults is, of course, to allow Perl programmers to write code in a more modern way and newcomers to program in a safer environment without having to know the sometimes arcane or niche ways to activate such an environment.