asaaki

class Boolean
  TRUE_VALUES  = [true,  1, :true,  "true",  "1", "t", "T", "yes", "y", "Y"]
  FALSE_VALUES = [false, 0, :false, "false", "0", "f", "F", "no",  "n", "N"]
  ALL_VALUES   = TRUE_VALUES + FALSE_VALUES
  InvalidInput = Class.new(StandardError)

  def initialize(input)
    @input = input
  end

asaaki

### WHY AND HOW
#
# ConCache has some nice features, the ones we will use here are:
#
# `get_or_store`:
# Retrieve a cached value or store a new one.
# Blocks other processes until the value is written,
# then the other processes will read the cached value.
#
# `callback` function:

asaaki

awk 'NR >= 100 && NR <= 300' file.in
sed -n '100,300p' file.in
# there are also solutions with head+tail, but it's not very intuitive for me

# example with bzipped files:
bzcat file.in | awk 'NR >= 100 && NR <= 300'
bzcat file.in | sed -n '100,300p'

asaaki

# Wrap it in a task (or just spawn a process) to not block your IEx shell
# or the following function calls:
Task.start(fn ->
  Stream.interval(1000) # in ms, so quite high-resolution loops are possible
  |> Stream.map(fn (_) -> "Tick!" end)
  |> Stream.each(fn (v) -> IO.puts(v) end)
  |> Stream.run # this will block the process forever!
end)

# For serious usage you also would need to supervise this process

asaaki

#!/bin/sh
CURRENT_DIR=$( cd "$(dirname "$0")"; pwd )
CURRENT_DIR=$( cd ${0%/*} && pwd -P )

echo $CURRENT_DIR

asaaki

class FunWithStringNext < ActiveRecord::Base
  def create_identifier
    total = FunWithStringNext.count
    # ENUMERATOR: identifier_generator.take(total).last
    generate_identifier_by_count(total)
  end

  def identifier_generator
    Enumerator.new do |yielder|
      init = INITIAL_IDENTIFIER.dup

asaaki

CondTest.run

*** &CondTest.cond_with_true/0 ***
72.2 sec   536M iterations   0.14 μs/op

*** &CondTest.cond_with_atom/0 ***
72.8 sec   536M iterations   0.14 μs/op

*** &CondTest.cond_with_truthy_evaluation/0 ***
76.4 sec   536M iterations   0.15 μs/op

asaaki

class BaseService
  class << self
    def add_error(name, message)
      error_klass = Class.new(StandardError) do
        define_method :initialize do |msg = message|
          super(msg)
        end
      end

      const_set(name, error_klass)

asaaki

# Stolen from <http://stackoverflow.com/a/9025552/653173>
module HashExt
  def subhash(*keys)
    keys = keys.select { |k| key?(k) }
    Hash[keys.zip(values_at(*keys))]
  end
end

asaaki

defmodule SigilZ do
  defmacro sigil_z(input, flags) do
    quote do
      [input: unquote(input), flags: unquote(flags)]
    end
  end
end

# then: