aruprakshit

class Object
  def send_through(object, *args)
    object.dispatcher_for(self).call(self, *args)
  end
end

module Dispatcher
  class DispatcherNotFound < StandardError; end

  def self.extended(klass)

aruprakshit

"ab"

"a
b"

aruprakshit

def store(provider, board, status)
  # @connection is a PG::Connection object
  # @logger is a Logger object
  
  # The part before `.each` is inconsequential, it's just a prepared statement and we're 
  # iterating over the results.
  @connection.exec_prepared(TYPE, [provider, board].concat(statement status)).each do |row|
    # Ignore this
    @logger.debug(Harvester::Runner) do
      Scrawl.new(label: "insert", table: TABLE, id: row["id"])

aruprakshit

class Array
  def number_of_items_deleted(char)
    self.size - self.tap { |o| o.delete(char) }.size
  end  
end 

puts %w(a b a d t r).number_of_items_deleted 'a'
# >> 2

aruprakshit

Originally published in June 2008

When hiring Ruby on Rails programmers, knowing the right questions to ask during an interview was a real challenge for me at first. In 30 minutes or less, it's difficult to get a solid read on a candidate's skill set without looking at code they've previously written. And in the corporate/enterprise world, I often don't have access to their previous work.

To ensure we hired competent ruby developers at my last job, I created a list of 15 ruby questions -- a ruby measuring stick if you will -- to select the cream of the crop that walked through our doors.

What to expect

Candidates will typically give you a range of responses based on their experience and personality. So it's up to you to decide the correctness of their answer.

aruprakshit

require 'socket'
require 'fiber'


#A list of readables and writables for IO.select, and which fiber is waiting for which IO
watch = {
  readable: {}, #{io => fiber}
  writable: {}
}

aruprakshit

Enumerable is a module, and Enumerator is a class. So that should tell you a lot out the the box. Enumerable is a set of behaviors and functionality you'd want to add to a class. The Enumerator class is something you get objects from itself.

aruprakshit

class Wrong
  def method_missing(m, *)
    if m =~ /\Ahello_(.+)\z/
      puts "Hello, #{$1.capitalize}"
    else
      super
    end
  end
end

aruprakshit

Enumerable#to_a says, that it can take arguments also. Lets try

(1..4).to_a(1,2)
#ArgumentError: wrong number of arguments (2 for 0)

Oops! Why then error ? Because Enumerable#to_a called actually Range#each which don't accept any arguments. Now look the below code :-

aruprakshit

# First check is always #respond_to? , if it returns false, then #respond_to_missing? will be called, otherwise #respond_to_missing? 
# will never be called. For all regular methods( which has been created by def, define_method, in C-implementation etc), thus we get
# false, while we pass the method name to the #respond_to_missing?. Because, first check has been done inside #respond_to?, and it
# returns true. That's why second output is [true, false]. Because, #foo is a regular method.

# Now why the second output is [true, true] ? The reason, I already explained, again #baz is not a regular method, so first check in
# #respond_to? return false, thus check goes to #respond_to_missing?. As I implemented it, so as per the implementations it is giving
# true, which in turn caused #respond_to? method to returns to true.