BernardK

BernardK

Programming Ruby 3.2 (5th Edition): B1.0 page 205, Only then do we create

@noelrappin

page 205, paragraph after the code, line 2 :

then blocks at Ractor.receive. Only then do we create the reading ractor

Because of “Only then” I thought that creating the second Ractor could only take place when the first is waiting on receive. But the trace shows that both Ractors are created, then the blocks are scheduled.

On page 204 (par. 5, code for one, line 1) I liked “Moving down the file”, for a possible replacement of “Only then”.

Having said that, it’s impressive to see the reader sending several times without waiting for a take.

def displayWord(p_word)
    p_word.nil? ? "^nil^" : "|#{p_word}|"
end
    
puts "*** (main) about to create counter"
counter = Ractor.new(name: "counter") do
  puts ">>> ccccc in counter block"
  result = Hash.new(0)
  while (word = Ractor.receive)
    puts "ccccc in counter received word=#{displayWord(word)}"
    result[word] += 1
    puts "ccccc looping"
  end
  puts "ccccc in counter while ended word=#{displayWord(word)}"
  result
end

puts "*** (main) about to create reader"
Ractor.new(counter, name: "reader") do |counter|
  puts ">>> rrrrr in reader block"
  File.foreach("testfile") do |line|
    puts "rrrrr line=#{line}"
    line.scan(/\w+/) do |word|
      puts "rrrrr about to send word=#{displayWord(word)}"
      counter.send(word.downcase)
      puts "rrrrr after send"
    end
  end
  puts "rrrrr about to send nil"
  counter.send(nil)
end

puts "*** (main) about to take counter"
counts = counter.take
counts.keys.sort.each { |k| print "#{k}:#{counts[k]} " }
puts
% ruby -w ractor_word_count_flipped.rb 
*** (main) about to create counter
<internal ... experimental ...
*** (main) about to create reader
*** (main) about to take counter
>>> ccccc in counter block
>>> rrrrr in reader block
rrrrr line=This is line one
rrrrr about to send word=|This|
rrrrr after send
rrrrr about to send word=|is|
rrrrr after send
rrrrr about to send word=|line|
ccccc in counter received word=|this|
...

First Post!

noelrappin

noelrappin

Author of Modern Front-End Development for Rails

Thanks!

Where Next?

Popular Pragmatic Bookshelf topics Top

brianokken
Many tasks_proj/tests directories exist in chapters 2, 3, 5 that have tests that use the custom markers smoke and get, which are not decl...
New
jesse050717
Title: Web Development with Clojure, Third Edition, pg 116 Hi - I just started chapter 5 and I am stuck on page 116 while trying to star...
New
mikecargal
Title: Hands-On Rust (Chapter 11: prefab) Just played a couple of amulet-less games. With a bit of debugging, I believe that your can_p...
New
leba0495
Hello! Thanks for the great book. I was attempting the Trie (chap 17) exercises and for number 4 the solution provided for the autocorre...
New
New
creminology
Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...
New
EdBorn
Title: Agile Web Development with Rails 7: (page 70) I am running windows 11 pro with rails 7.0.3 and ruby 3.1.2p20 (2022-04-12 revision...
New
Keton
When running the program in chapter 8, “Implementing Combat”, the printout Health before attack was never printed so I assumed something ...
New
New
dachristenson
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
New

Other popular topics Top

AstonJ
Or looking forward to? :nerd_face:
498 14002 274
New
Exadra37
Please tell us what is your preferred monitor setup for programming(not gaming) and why you have chosen it. Does your monitor have eye p...
New
New
AstonJ
You might be thinking we should just ask who’s not using VSCode :joy: however there are some new additions in the space that might give V...
New
AstonJ
Thanks to @foxtrottwist’s and @Tomas’s posts in this thread: Poll: Which code editor do you use? I bought Onivim! :nerd_face: https://on...
New
PragmaticBookshelf
Build efficient applications that exploit the unique benefits of a pure functional language, learning from an engineer who uses Haskell t...
New
sir.laksmana_wenk
I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc. However, I don’t...
New
AstonJ
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
New
NewsBot
Node.js v22.14.0 has been released. Link: Release 2025-02-11, Version 22.14.0 'Jod' (LTS), @aduh95 · nodejs/node · GitHub
New
mindriot
Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...
New

Sub Categories: