asaaki

require 'active_support'

module MyConcern
  extend ActiveSupport::Concern

  class PrivateClass
    def self.pcall
      :pcall_result
    end
  end

asaaki

# Ruby's do notation

# Don't do!

module Foo; end
module FooDo do; end
#=> SyntaxError: unexpected keyword_do, expecting ';' or '\n'

class Foo; end
class FooDo do; end

asaaki

# ref:
# https://github.com/sinatra/sinatra/blob/8c2504c/lib/sinatra/base.rb#L1082-L1085
module HashWithIndifferentAccess
  def self.new
    Hash.new {|hash,key| hash[key.to_s] if Symbol === key }
  end
end

# ref:
# https://github.com/sinatra/sinatra/blob/8c2504c/lib/sinatra/base.rb#L1068-L1080

asaaki

#!/bin/sh

POSSIBLE_VALUES="foo bar baz"
TEST_VALUE=$1

echo $POSSIBLE_VALUES | grep $TEST_VALUE 1>/dev/null
exit $?

asaaki

# Helper:
# alternative `puts` with a non-nil return value
# similar to many method calls which could be useful with logical operations
def puts_with_true(arg)
  puts(arg)
  true
end

# puts returns `nil` by default
puts 1 && 2

asaaki

# example from:
# http://michal.muskala.eu/2017/02/10/error-handling-in-elixir-libraries.html
defmodule YourLibrary do
  defmodule Error do
    defexception [:reason]
  
    def exception(reason), 
      do: %__MODULE__{reason: reason}
  
    def message(%__MODULE__{reason: reason}), 

asaaki

Code.compiler_options(ignore_module_conflict: true)
base_dir = "web/models"
if File.exists?(base_dir) do
  for model_file <- File.ls!(base_dir) do
    for {mod, _bytes} <- Code.load_file(model_file, base_dir) do
      Code.eval_quoted(quote(do: alias unquote(mod)), [mod: mod])
    end
  end
end
Code.compiler_options(ignore_module_conflict: false)

asaaki

# frozen_string_literal: true

# Gemfile:
# # frozen_string_literal: true
# source 'https://rubygems.org'
# gem 'benchmark-ips'

require 'bundler/setup'
require 'benchmark/ips'
require 'set'

asaaki

Keybase proof

I hereby claim:

• I am asaaki on github.
• I am asaaki (https://keybase.io/asaaki) on keybase.
• I have a public key ASBo4idVp9JxHEySo-IQ8g3-CFIvbUj93GGL_H8j8YpURwo

To claim this, I am signing this object:

asaaki

[some_data.fetch('a_string', fallback_string)].reduce(replacer) { |r, s| s == criteria ? r : s }

# or a way simpler workaround:
(origin = some_data.fetch('a_string', fallback_string)) == criteria ? replacer : origin