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puts "<< De Morgan's laws >>\n\n"

PAIRS = [
  [false, true],
  [true, false],
  [true,  true],
  [false, false]
]

puts "\"NOT (A AND B)\" is the same as \"(NOT A) OR (NOT B)\""

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require 'forwardable'

class Said
  attr_reader :msg

  def initialize(msg = nil)
    @msg = (msg || '').freeze
  end

  def loud_enough?

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# Simple logger
logger = Logger.new(STDOUT)

# Some object
Foo = Struct.new(:hello, :goodbye)

foo = Foo.new
foo.hello = 'Hola'
foo.goodbye = 'Adiós'

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brew tap homebrew/versions
brew install v8-315
brew unlink v8-315 && brew link v8-315
brew link --force v8-315
bundle config --global build.libv8 --with-system-v8
bundle install --full-index --jobs 4 --clean

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echo "BEGIN updating: $(pwd)"

cd "$1/.."

git fetch --all --prune --verbose

[[ -a Gemfile && "$(gem query --installed '^bundler$')" == 'false' ]] && gem install bundler --no-document

bundle check || bundle install

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ruby -W2 -v -e '                                                                                                                                                                                     (ruby-2.2.2@benchprep) wip-simulation-endpoints 9a603b95e ✗
puts "before"
module Foo
  puts "- Foo -"
end

puts "more"
module Foo::Bar
  puts "- Foo::Bar -"
end

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explain (analyze on, buffers on, verbose on, timing on)
select l.id, l.simulation_id, l.user_id, l.content_package_id, l.score, l.result, l.total_time_taken, l.created_at, l.updated_at
from simulation_results l
inner join (
  select simulation_id, max(created_at) created_at
  from simulation_results
  where user_id = 827911
  group by simulation_id
) r
on l.simulation_id = r.simulation_id and l.created_at = r.created_at

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Postgres EXPLAIN Lunch & Learn @ BenchPrep

EXPLAIN Explained video on YouTube

What EXPLAIN doesn't do

• Tell you why a particular index isn't used
• Explain how to rewrite your queries
• Show what other factors make the DB slow
• Tell you how much time the request took outside the DB

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yyyyy/:oyyyysyyyyyyyyyysssoooo+++++//+///+/+++++/++oosso/:::+++++ooooossyyyyysssssso+:----.````````````-+ssyyyyyyysssssss/-/hyyyyyyyyyyyyyyyssssssssss+-:yhhhhhhhhhhhhhyyyyyysss+..+so++//:+sdNNNNMMMMMMMMMMMMMMMMMMMMMMMMMNNMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMNNNNNNNNNmmdhydddy///++/---:-:--/ossoossssyyyyyyyyhho+syyssssoooooo+++++//////:::---::::::://+++++ooo++++++/++/://++++++oooo+/-.:/:.-/::/:://:.:--+oo++oosssoossyssshyyyysossyyhysyyyyyysysoso+oo+ss++++so:.-:::--+:::://-//:--//::+syy
yyyyy+-/yyyyyyyyyyyyyyyyyyyyyyyyyys//ssssssssossssssssso/--:++oo+ooooosysyyyyyyyyyyys/-----````````````.:/:::::::///++oss/-/yyyhhyyyyyyyyyyyssyyssssss+-:shhhhhhhhhhhhhhhhhhyyyyo-.ohyhhyhdmNMNNNMMMMMMMMMMMMMMMMMMMMMMMMMMNMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMNNNNNNNNmdhhhhys:-o+//----::-:+ooossssyyyyyyyyyhhhys+sssssssooooooo+++///:::::---.---::::////+++++++++++///////++++++++++++++:..:/--.//:/:::::--:-/ooooo+sysssshhsyyyssysyyhhyyyyyyysssyysoooo+ooo++/+::++::+o+/:+o++/-+oo++++ooo++/sy
yyyyy+-/yyyyyyyyyyyyyy

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To easily limit the execution of RSpec tests while you are developing use the power of the .rspec opts file and RSpec tags.

Tags can be added to any RSpec method describe, context, it, etc.

The are simply arguments passed as a Hash to the method.

describe 'foo', focus: true do
 context 'bar', slow: true do