Start clean

I created an alias irb=irb --sample-book-mode

This removes the complex prompt like irb(main):001:0> and gives plain and simple >> instead.

Get Help!

When programming in Python, even today I use dir in Python REPL. So I was looking for the equivalent in Ruby land.

Turns out I was comparing apples and oranges (so to speak)

As of early 2022, irb has awesome help built-in. It has good autocompletion. So just typing . may be enough to know list of methods available.

While I noted similarities and difference between Ruby and Python, as I was learning the basics here, here and here there is official document on the Ruby site. See this

Methods

• Ruby functions start with def just like python, but end with end keyword.
• splat operator (*) to destructure an array into a List. This is similar to Python splat operator

>>> x = [10, 20, 30]
>>> a, *b = x
>>> print(f'{a=}, {b=}')
a=10, b=[20, 30]

Python ☝️, Ruby 👇

>> first, *rest, last  = ["a", "b", "c", "d"]
=> ["a", "b", "c", "d"]
>> first
=> "a"
>> rest
=> ["b", "c"]
>> last
=> "d"
>>

But in Ruby, splat operator can also create an array.

>> q=*135
=> [135]
>> q
=> [135]

In the second scenario¹, it creates an array. I think this is useful for scenario where the method accepts either a single element or an array.

Learning continues …

• idiomatic(?) ruby loops use each like :

(1..5).each do |counter|
  puts "iteration #{counter}"
end

Although python like loop also work

for counter in 1..5
  puts "iteration #{counter}"
end

• array.each_with_index is like python’s enumerate

• Ruby seems to have multiple ways to do the same thing, as opposed to Python’s

There should be one– and preferably only one –obvious way to do it.

e.g. a.map do .. end, a.map { |el| e.something } and a.map(&:method)

There are multiple ways to install ruby on your machine.

Official recommendation is to use your OS’s package manager like apt, pacman or brew

If you are using a version manager, rvm (Ruby Version Manager) seems to be popular. But in the past, I started using asdf, so I’ve decided to stick with it. It is also mentioned (first in the list) on the official Installing Ruby page 😄

asdf plugin add ruby https://github.com/asdf-vm/asdf-ruby.git
asdf list all ruby
asdf install ruby latest

At the time of this writing 3.1.0 is the latest

I’ve meaning to learn Ruby for some time now.

Especially, when I dabbled from time to time in Elixir, I felt that knowing Ruby may be an advantage (since Elixir syntax similar to Ruby)

No one learns (I think) Ruby just for the language. They learn it so that they can use Ruby on Rails (RoR as popularly known) RoR, in case you don’t know, is the Web framework. Like Django in Python land. But there are a lot of web frameworks like Flask, Pyramid, FastAPI to name some.