Just Aristotle and Philippe this time (Graham chipped in on IRC):
use VERSION.
Should "did you use VERSION?" become the new "did you use strict and warnings?"These are some answers to the Week 286, 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 September 15, 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.
You are given an array of integers, @ints, whose length is a power of 2.
Write a script to play the order game (min and max) and return the last element.
Example 1
Why does this not give flinstone and rubble?
$fn{"fred"} = "flintstone";
$fn{"barney"} = "rubble";
foreach $per (qw< barney fred >) {
print " he's $per $fn($per).\n";
}
Yep, that's right - the first dozen talks have been accepted for this year's London Perl and Raku Workshop. This puts our schedule at approximately 50% full, so if you are thinking about talking at the workshop then submit your proposal now!
If you aren't thinking about talking then have a think about what you've been doing in the Perl and/or Raku space the last five years, or even just the general IT and development space. Perhaps there's something interesting you can talk about? If you don't feel it's a full fat talk then submit a lightning talk instead.
The London Perl and Raku Workshop will take place on 26th Oct 2024. Thanks to this year's sponsors, without whom LPW would not happen:
If you would like to sponsor LPW then please have a look at the options here: https://act.yapc.eu/lpw2024/sponsoring.html
After over a month without a PSC meeting, this was the first meeting of the new, shiny PSC. Today, we:
These are some answers to the Week 286, 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 September 15, 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.
Write a program which outputs one word of its own script / source code at random. A word is anything between whitespace, including symbols.
Example 1
If the source code contains a line such as: 'open my $fh, "<", "ch-1.pl" or die;'
then the program would output each of the words { open, my, $fh,, "<",, "ch-1.pl", or, die; }
(along with other words in the source) with some positive probability.
Example 2
Technically 'print(" hello ");' is *not* an example program, because it does not
assign positive probability to the other two words in the script.
It will never display print(" or ");
Example 3
I created a function in Perl called pg_dt, that will convert PostgreSQL’s datetime values into Perl’s DateTime values and vice versa. This is useful both when you want to store DateTime values into the database, or want to convert the pg datetime/timestamp value from the database into a DateTime object value that Perl can use.
I really can’t seem to include code blocks in my posts on this platform (tried Preview with Markdown and Markdown With SmartyPants without success), so you can read the rest of this article on my blog.
The Dancer Core Team is happy to announce that Dancer2 1.1.1 is on its way to CPAN. This is a maintenance release that deals with the following issues:
[ BUG FIXES ]
* GH #1712: Fix use of send_as in templates (Andy Beverley)
[ DOCUMENTATION ]
* PR #1706: Document missing logging hooks and log format option;
fix typo in logging test (Jason A. Crome)
Happy Dancing! Jason / CromeDome
These are some answers to the Week 285, 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 September 8, 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.
Compute the number of ways to make change for given amount in cents. By using the coins e.g. Penny, Nickel, Dime, Quarter and Half-dollar, in how many distinct ways can the total value equal to the given amount? Order of coin selection does not matter.
A penny (P) is equal to 1 cent.
A nickel (N) is equal to 5 cents.
A dime (D) is equal to 10 cents.
A quarter (Q) is equal to 25 cents.
A half-dollar (HD) is equal to 50 cents.
In which thousands become millions, as we achieve a near-linear solution.
Perl v5.40 introduced native true and false keywords. Unfortunately not all CPAN modules are ready to use them. One of those not yet ready is Mojo::Pg.
Normally you'd want to pass booleans to your queries as just 1's and 0's. However, since Mojo::JSON's true & false stringify to 1 and 0, my 5.38-using codebase is full of Mojo::Pg queries with Mojo::JSON's true and false as arguments.
This is a problem if I want to upgrade the perl interpreter of that project to Perl v5.40, because if I write "use v5.40;" in the file that contains those boolean keywords, Perl's builtin booleans will be used instead, which don't stringify to 1 and 0, but to 1 and the empty string, which can't be used by DBD::Pg in boolean fields and makes DBD::Pg throw an exception.
The solution I found was to subclass Mojo::Pg::Database, and wrap the query method, so that if Perl's builtin booleans are found, they are replaced in the query with native Pg booleans.
The source of the module and a lot more information can be found in my blogpost, here.
I have not been able to figure out how to run an async thread in the background while using a REPL like reply. The moment I run the main loop, it takes over the input from the REPL. Here's what a typical failed REPL session might look like.
These are some answers to the Week 284, 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 September 1, 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.
You are given two list of integers, @list1 and @list2. The elements in the @list2 are distinct and also in the @list1.
Write a script to sort the elements in the @list1 such that the relative order of items in @list1 is same as in the @list2. Elements that is missing in @list2 should be placed at the end of @list1 in ascending order.
Example 1
Input: @list1 = (2, 3, 9, 3, 1, 4, 6, 7, 2, 8, 5)
@list2 = (2, 1, 4, 3, 5, 6)
Ouput: (2, 2, 1, 4, 3, 3, 5, 6, 7, 8, 9)
Example 2
[This is my seventh YAPC / TPC. If you like, you can read about my other YAPC experiences: YAPC 2011, YAPC 2013, YAPC 2014, YAPC 2015, YAPC 2016, YAPC 2018.]
Well, after taking a very long break inspired (to understate it a bit) by the pandemic, I’m back to attending in-person Perl events with my seventh YAPC. Or, The Perl Conference, I suppose, but it still feels like YAPC to me. As per usual, here are some reflections.
Sometimes one needs an extra ounce of performance. Why not combine the high level semantics of Perl with the punch of assembly?
This repo includes various examples of how this can be done.
This block of code is valid Perl:
if (my $var1 = calc1()) {
say $var1;
} elsif (my $var2 = calc2()) {
say "$var1, $var2";
}As you can see, $var1, which is declared in the if clause, is visible inside the elsif clause too.
Perl never ceases to amaze me!
(Also appears in my blog)
These are some answers to the Week 284, 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 September 1, 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.
You are given an array of integers, @ints.
Write a script to find the lucky integer if found otherwise return -1. If there are more than one then return the largest.
A lucky integer is an integer that has a frequency in the array equal to its value.
Example 1
Input: @ints = (2, 2, 3, 4)
Output: 2
Example 2
Input: @ints = (1, 2, 2, 3, 3, 3)
Output: 3
Example 3
Just Graham and Aristotle this time.
Chapter 3 of Higher Order Perl describes various approaches to memoization of an expensive function: private cache and the Memoize module. The book was written in 2005 (Perl was at version 5.8 back then) , so it does not include another way for function caching that is now available : caching through state variables (introduced in Perl 5.10). The Fibonacci example considered in HOP also requires the ability to initialize state hash variables (available since Perl 5.28). The code below contrasts the implementation with a state variable v.s. the memoize module:
blogs.perl.org is a common blogging platform for the Perl community. Written in Perl with a graphic design donated by Six Apart, Ltd.
