JoshCheek

# https://babeljs.io/blog/2018/07/19/whats-happening-with-the-pipeline-proposal
module Pipeable
  def |(fn)
    fn.to_proc.call self
  end

  refine(Enumerable) { include Pipeable }
  refine(Proc)       { include Pipeable }
  refine(Array)      { include Pipeable }

JoshCheek

p RUBY_VERSION: RUBY_VERSION

def ab(a, b:)
  [a, {b: b}]
end

puts "Three dots:"
def dots(...) ab(...) end
pp real_sig:    method(:ab).parameters,
   wrapper_sig: method(:dots).parameters,

JoshCheek

// code for the screenshot in this tweet https://twitter.com/josh_cheek/status/1408853467150663680
#include "stdio.h"

void inc1(int& n) { ++ n; }
void inc2(int* n) { ++*n; }

int main(int argc, char** argv) {
  int a = 0, b=0;
  printf("a=%d, b=%d\n", a, b);
  inc1(a); inc2(&b);

JoshCheek

# An example to help me explain my thoughts in this tittwer convo:
# https://twitter.com/dorianmariefr/status/1407972746093641732
#
# Note that I ran this code on MRI 3.0.1, I assume it works on other versions too, but I did not try it.

# -----------------------------------------------------------------

# For simplicity, we'll only deal with keyword args in this example,
# I initially wrote it to deal with ordinals and blocks, but that got pointlessly dense

JoshCheek

# Context: https://twitter.com/josh_cheek/status/1406730934880198664

# NOTE: If you want to run this in bash, you have tod ouble-escape the newlines being passed to `tr`

curl -sL http://yaml.org/type/bool.html |        # grab the docs on booleans
  nokogiri -e 'puts $_.css("pre.screen").text' | # extract the values they mention
  tr -d \n |                                     # remove their whitespace formatting
  tr \| \n |                                     # each BNF "or" option gets its own line
  ruby -r yaml -lne 'p [$_, YAML.load($_)]' |    # print each input value and what it parses to
  bat -l ruby                                    # syntax highlight it

JoshCheek

# I used this to generate the public / private keypair and sign them
require 'base64'
require 'openssl'

private_key = OpenSSL::PKey::RSA.generate 1024
public_key  = private_key.public_key
signature   = private_key.sign
  OpenSSL::Digest::SHA256.new,
  public_key.to_pem
)

JoshCheek

https://sites.google.com/site/steveyegge2/five-essential-phone-screen-questions

# Area Number One: Coding
  # 1. Write a function to reverse a string.
  echo -e a\\nab\\nabc\\nabcdef© | ruby -lne 'puts $_.reverse'

  # 2. Write function to compute Nth fibonacci number
  seq 0 10 | ruby -ne '
  a, b = 0, 1
  $_.to_i.times { a, b = a+b, a }

JoshCheek

# alternative solutions to https://blog.arkency.com/semantic-blind-spot-in-ruby-case-statement/
class CaseWhen
  def call(number)
    boundaries = [0, 4, 8, 11]
    messages   = ['low value', 'medium value', 'high value']
    boundaries.each_cons(2).zip messages do |(low, high), desc|
      return desc if low <= number && number < high
    end
    'invalid value'
  end

JoshCheek

require 'objspace'
require 'fiddle'
require 'json'

def heap
  $heap ||= ObjectSpace
    .dump_all(output: :string)
    .lines.map { JSON.parse _1, symbolize_names: true }
    .reject { |obj| %w[ROOT IMEMO DATA].include? obj[:type] } # probably overzealous
end

JoshCheek

echo Josh | ruby -r ./tracer.rb -e '
class User
  def initialize(id, name)
    @id, @name = id, name
  end

  def to_s
    "User #@id: #@name"
  end
end