blogs.perl.org

I feel that Perl users are losing confidence because of negative feedback from other communities.

The opinions of people who intend to harm Perl are 99% useless in my experience.

Handling character codes is actually simple.

Because all you have to do is remember the following three things.

1. use utf8 and save file as UTF-8

2. if you print text, encode text to platform charset(Linux is UTF-8, Windows is cp932)

3. if you get text from outside, decode text from platform charset(Linux is UTF-8, Windows is cp932)

If "use v7;" enabled "use utf8", it would be less memorable and less mistake.

Beginners will first remember that Perl source code is stored in UTF-8.

Next, the introductory person will notice that using a print statement results in a "Malformed ..." warning.

And, to get rid of the warning, he will have to encode with the platform character code.

Once he have learned that, he will naturally learn that he need to decode when he bring in text from the platform.

https://perlweeklychallenge.org/blog/weekly-challenge-064

These are some answers to the Week 105 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days (March 28, 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: Nth Root

You are given positive numbers $N and $k.

Write a script to find out the $Nth root of $k. For more information, please take a look at the wiki page.

Example:

Input: $N = 5, $k = 248832
Output: 12

Input: $N = 5, $k = 34
Output: 2.02

GraphQL is the new, shiny way to do APIs. It minimises number of round-trips for clients to query what need. But what about real-time updates? How can we cut down the time needed for clients to get new information? Are we forcing them to constantly poll? That seems expensive and also slow.

GraphQL's official standard now includes "subscriptions". The obvious transport for that is WebSockets, and the de facto standard for that is Apollo GraphQL's subscriptions-transport-ws.

As of 0.16, Mojolicious::Plugin::GraphQL supports WebSockets, and GraphQL subscriptions, conforming to the Apollo protocol.

A well-known model for distributing information in an event-driven way is "publish/subscribe" (or "pub/sub"). To both demonstrate the subscription capability, and to provide useful functionality, there is now a new "convert plugin" for GraphQL with the two Mojo modules that implement pub/sub (with Redis and PostgreSQL): GraphQL::Plugin::Convert::MojoPubSub.

As one of Perl user, +1 "use v7;" in newer version of Perl.

The use v syntax is worth it.

use v5.14

This syntax is the history of Perl and is also a mechanism for maintaining backward compatibility with newer versions of Perl.

The reason this was not used is simply the small granularity.

I don't remember much about Perl, so I can't tell the difference between use v5.20 and use v5.30.

And because the warnings and utf8 aren't turn on, I couldn't find a meaning to actively use it.

use v7; is very easy to understand.

use v7;

Imagine an application user actively uses it instead of writing use strict, use warnings, use utf8;, use feature'say', ....

I also think that I use it aggressively in application code.

Miss out blogging for a while. Here just write some lines on the recent PWC coding experience.

Challenge 061

ch-1 :

Enumeration

ch-2 :

Before coding, I had thought it was a complicated task for regular expression. It turned out smoother.

I use a subroutine possible_octet to check whether a number can be a part of IPv4 octet.

Its content:

These are some answers to the Week 104 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days (March 21, 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: Fusc Sequence

Write a script to generate first 50 members of FUSC Sequence. Please refer to OEIS for more information.

The sequence is defined as below:

fusc(0) = 0
fusc(1) = 1
for n > 1:
    when n is even: fusc(n) = fusc(n / 2),
    when n is odd: fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)

Fusc Sequence in Raku

https://perlweeklychallenge.org/blog/weekly-challenge-063

There's a lot in it and we could question some of the methodology, but here's some thoughts.

Perl developers are older (and there aren't that many of them) but salaries are excellent.

I would note that TIOBE didn't match up too closely with common usage but there's no silver lining.

Ruby is now in consistent decline, I have read people linking this to Twitter moving away from Ruby on Rails but can't cite that claim. My observation is that RoR seems to have gone out of fashion in favor of lightweight server frameworks and I would suggest that Kubernetes has sidelined Puppet, so organizations aren't bringing in Ruby via apps/frameworks they want to use.

Some months ago I started working in a system similar to ActiveRecord. But then it became pretty big so then I centered my attention in a SQL AST manager instead.

So I made a library that is basically an Arel port. You can see the README with most of the basic info. After looking at implementations in CPAN I realized there are many of them already but all of them based on hash structures.

This impl can instead represent a full SQL AST mainly using builder chainable methods.

I need some feedback on wether you think it will be something that is useful.

Thanks in advance.

Repo link: https://bitbucket.org/juankpro/perl-sql/src/master/

PD: Here is another question. If you try to download and use the lib right now it will not work because it depends on another library made by me as well: https://bitbucket.org/juankpro/model-support/admin

This library is a group of packages with somewhat unrelated utility functions that allows me to support my own perl OOP engine implementation shared through other libraries I'm working on. I don't know what's the best approach to handle this. Is it ok to upload this library separately? if I need to reuse this code again, how do I prevent collisions if my other libs will use it as well?

These are some answers to the Week 100 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Task 1: Fun Time

You are given a time (12 hour / 24 hour).

Write a script to convert the given time from 12 hour format to 24 hour format and vice versa.

Ideally we expect a one-liner.

Example 1:

Input: 05:15 pm or 05:15pm
Output: 17:15

Example 2:

Input: 19:15
Output: 07:15 pm or 07:15pm

1. Previously it was only possible to output text with strings using text_out() method. Now, a more versatile and modern way is added with text_shape() method that converts text string in a series of glyphs, that allows the following:

   • Full unicode bidi processing
   • Support for font ligatures
   • Native support for right-to-left text
   • Transparent font substituion where a single font does not contain necessary glyphs

   In addition to that, infrastructure was added to support RTL and shaping in all standard Prima widgets. Run podview Prima::Drawable::Glyphs and check out the examples in the end of the document.

2. PostScript backend rewritten to generate embedded Type1 fonts. This allows to generate unicode text in PostScript documents.

3. In X11 backend, standard key combination (Ctrl+Shift+U) accepts unicode hex number as a character input. Try typing "a" then Ctrl+Shift+U 300 ENTER.

4. Prima::*Dialog packages are moved to Prima::Dialog::* namespace

The Dancer Core Team would like to announce the availability of Dancer2 0.300004. This release brings several important fixes and enhancements:

• Session cookies can be restricted to a first-party or same-site context

• There were a number of spots where Dancer2 would return a 500 error upon receiving an invalid request, rather than (correctly) returning 400 - Bad Request. Many, if not all, of these have been fixed.

For more information about same-site context, please refer to [RFC-6265bis]( https://tools.ietf.org/html/draft-ietf-httpbis-cookie-same-site).

To use this, add the cookie_same_site key to your session engine configuration in the appropriate YAML file. Valid settings include Strict, Lax, and None.

The complete changelog is as follows: 0.300004 2020-05-26 20:52:34-04:00 America/New_York

There have been several! LANraragi, ZEVENET CE, LedgerSMB, and Sympa. All great perl software!

LANraragi v.0.7.0 -- Cat People (Putting Out Fire)

Web application for archival and reading of manga/doujinshi. Lightweight and Docker-ready for NAS/servers.

This release includes an API revamp, categories have finally been added, PDF files are now first class citizens, Docker image is much smaller, and many other fixes and small features.

Check it out here: https://github.com/Difegue/LANraragi/releases/tag/v.0.7.0

ZEVENET Community Edition v5.11.1

The community edition of this load balancer appliance is bugfixes.

Check it out at: https://github.com/zevenet/zlb/releases/tag/v5.11.1

LedgerSMB 1.7.14

This accounting software's release is composed primarily of bugfixes.

Check it out at: https://github.com/ledgersmb/LedgerSMB/releases/tag/1.7.14

Sympa 6.2.56

This release is a all bugfixes for this mailing list management software

Check it out at: https://github.com/sympa-community/sympa/blob/6.2.56/NEWS.md

These are some answers to the Week 99 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Spoiler Alert: This weekly challenge deadline is due in a couple of days (February 14, 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: Pattern Match

You are given a string $S and a pattern $P.

Write a script to check if given pattern validate the entire string. Print 1 if pass otherwise 0.

The patterns can also have the following characters: - ? - Match any single character. - * - Match any sequence of characters.

Example 1:

Input: $S = "abcde" $P = "a*e"
Output: 1

Example 2:

Input: $S = "abcde" $P = "a*d"
Output: 0

Example 3:

Product SubArray

Given a list of 4 or more numbers, write a script to find the contiguous sublist that has the maximum product. The length of the sublist is irrelevant; your job is to maximize the product.

Example

Input: [ 2, 5, -1, 3 ]

Output: [ 2, 5 ] which gives maximum product 10.

The easiest (but probably not the fastest) method would be to start from each position and compute the products of all the possible sublists starting at the position, remembering the positions where the product is maximal.

I automatically reached for List::Util’s product to get the products easily, but alas! Running

product(-1, 3)

caused a Floating point exception (bug reported). So, I had to implement product myself:

After almost half a year of work I finally publish my new project Vikna which is also the subject of my talk at the upcoming Conference in the Cloud.

As the subject says, it is a clear pre-release and a proof of concept for the preview of those who might be interested. In the project I tried to get hold of all the best what Raku can offer in the field of asynchronous/threaded processing and OO. Whish you can as much fun trying it as I have in developing!

https://perlweeklychallenge.org/blog/weekly-challenge-061

These are some answers to the Week 98 of the Perl Weekly Challenge organized by Mohammad S. Anwar.

Task 1: Read N-characters

You are given file $FILE.

Create subroutine readN($FILE, $number) that returns the first n-characters and moves the pointer to the (n+1)th character.

Example:

Input: Suppose the file (input.txt) contains "1234567890"
Output:
    print readN("input.txt", 4); # returns "1234"
    print readN("input.txt", 4); # returns "5678"
    print readN("input.txt", 4); # returns "90"

Read N-characters in Raku

This is my first attempt:

Sqitch is a database change management application. It currently supports PostgreSQL 8.4+, SQLite 3.7.11+, MySQL 5.0+, Oracle 10g+, Firebird 2.0+, Vertica 6.0+, Exasol 6.0+ and Snowflake.

Changelog at https://github.com/sqitchers/sqitch/releases/tag/v1.1.0