## Counting Fridays the 13th in Raku

The Raku solution to the following task: Write a script to find out how many dates in the year are Friday 13th, assume that the current Gregorian calendar applies.

The Raku solution to the following task: Write a script to find out how many dates in the year are Friday 13th, assume that the current Gregorian calendar applies.

## Dialogues with ChatPGP about the Raku programming language. Solving Task 1 of the Weekly Challenge 204

Let us ask ChatGPT to find a solution and then correct it to make it more Raku-ish. This task, the machine solved the thing from the first attempt, but you can follow how we managed to make it better and more compact. Most (except one) of the generated code workes without compiler errors, so I will not concentrate on it here.

Let us ask ChatGPT to find a solution and then correct it to make it more Raku-ish. This task, the machine solved the thing from the first attempt, but you can follow how we managed to make it better and more compact. Most (except one) of the generated code workes without compiler errors, so I will not concentrate on it here.

## The course of Raku

I am happy to report that the first part of the Raku course is completed and published. The course is available at course.raku.org.

I am happy to report that the first part of the Raku course is completed and published. The course is available at course.raku.org.

## Raku Challenge, Week 92, Issue 1

This week’s task has an interesting solution in Raku. So, here’s the task:

You are given two strings \$A and \$B. Write a script to check if the given strings are Isomorphic. Print 1 if they are otherwise 0.

This week’s task has an interesting solution in Raku. So, here’s the task:

You are given two strings \$A and \$B. Write a script to check if the given strings are Isomorphic. Print 1 if they are otherwise 0.

## Advent of Code 2020 Day 18/25 in the Raku programming language

Today there’s a chance to demonstrate powerful features of Raku on the solution of Day 18 of this year’s Advent of Code. The task is to print the sum of a list of expressions with +, *, and parentheses, but the precedence of the operations is equal in the first part of the problem, and … Continue reading “Advent of Code 2020 Day 18/25 in the Raku programming language”

## The second wave of Covid.observer

In this post, I am telling a story of how updating covid.observer became a bit problematic, and how one of the developers of the Rakudo compiler helped not only to remove the errors but also to speed up the whole system by 2x.

In this post, I am telling a story of how updating covid.observer became a bit problematic, and how one of the developers of the Rakudo compiler helped not only to remove the errors but also to speed up the whole system by 2x.

## Advent of Code 2020 Day 12.1/25 in the Raku programming language

Here is my solution of the first part of Day 12 of this year’s Advent of Code. The point in this solution is that I use multi functions a lot. Well, actually, the whole logic of the program is based on the dispatching rules of the variants of a single multi function. We start with … Continue reading “Advent of Code 2020 Day 12.1/25 in the Raku programming language”

## Advent of Code 2020 Day 9/25 in the Raku programming language

Day 9 of Advent of Code is here and the task is the following. Take a list of numbers and find the first one, which is not the sum of two of the 25 preceding numbers. my \$window = 25; my @data = ‘input.txt’.IO.lines.map: *.Int; say @data[(\$window ..^ @data).first({ @data[\$_] != any(@data[\$_ – \$window ..^ … Continue reading “Advent of Code 2020 Day 9/25 in the Raku programming language”

## Advent of Code 2020 Day 8/25 in the Raku programming language

Here is Day 8 of Advent of Code 2020. Today, we are building a program to read an execute programs in the assembly language. Well, a very limited assembly with only three opcodes and one register, accumulator. nop +0 acc +1 jmp +4 acc +3 jmp -3 acc -99 acc +1 jmp -4 acc +6 … Continue reading “Advent of Code 2020 Day 8/25 in the Raku programming language”

## Advent of Code 2020 Day 7/25 in the Raku programming language

Let’l look at Day 7 of this year’s Advent of Code. This day’s problem is about handling luggage at the airport. There are some rules like these: As you see, the rules dictate how you can put bags into other bags. The only characteristics of the bag is its colour. For example, if the bag … Continue reading “Advent of Code 2020 Day 7/25 in the Raku programming language”

## Advent of Code 2020 Day 6/25 in the Raku programming language

The task of Day 6 is to count letters :-). Well, not that straightforward. There’s some input like this split into groups and lines: abc a b c ab ac We have to count how many times each letter enters in each group. Again, the original task is more storyline-type and you’d better read it … Continue reading “Advent of Code 2020 Day 6/25 in the Raku programming language”

## Advent of Code 2020 Day 5/25 in the Raku programming language

On Day 5, they gave a task to find a seat number in a place. We have a list of occupied seats in a special form. Long story short, the rows and the seats within the row are encoded binary, but instead of 0 and 1, letters are used: F and B for rows and … Continue reading “Advent of Code 2020 Day 5/25 in the Raku programming language”

## Advent of Code 2020 Day 4/25 in the Raku programming language

In Day 4 of the Advent of Code, we are checking the fields of the passports. For each passport, there are a few fields labelled with a three-letter codes: byr (Birth Year) iyr (Issue Year) eyr (Expiration Year) hgt (Height) hcl (Hair Color) ecl (Eye Color) pid (Passport ID) cid (Country ID) The full record for a single passport contains colon-separated pairs key:value: … Continue reading “Advent of Code 2020 Day 4/25 in the Raku programming language”