tdg5

require 'tco_method'

module StackBuster
  def self.fact_yielder(n, acc = 1, &block)
    block.call(acc)
    n <= 1 ? acc : fact_yielder(n - 1, n * acc, &block)
  end
end

puts "StackBuster:"

tdg5

require "benchmark/ips"

def recursive_factorial(n)
  n < 2 ? 1 : n * recursive_factorial(n - 1)
end

def tail_recursive_factorial(n, accumulator = 1)
  n < 2 ? accumulator : tail_recursive_factorial(n - 1, n * accumulator)
end

tdg5

def itoa(int, base = 10)
  str = ""
  while int > 0
    str = ((int % base) + 48).chr + str
    int /= base
  end
  str
end

def itoarr(int, base = 10)

tdg5

require "tco_method"

class TCOInstance
  extend TCOMethod::Mixin

  attr_reader :tco_cycles

  def initialize
    @tco_cycles = 0
  end

tdg5

def self.pbt_deep_dup_build(clone, original)
  mapped = Set.new
  edges = [[clone, original]]
  while edges.any?
    builder, twin = edges.shift
    pair_hash = "#{builder.class.name}:#{builder.hash}~#{twin.hash}".hash
    next if mapped.include?(pair_hash)

    mapped << pair_hash
    pbt_dup_build(builder, twin)

tdg5

module PartiallyImplementedInterface
  def self.not_implemented_error(klass, method)
    raise NotImplementedError, not_implemented_message(klass, method), caller(2)
  end

  def self.not_implemented_message(klass, method_name)
    "#{method_name} must be implemented by subclasses of #{klass.name}!"
  end
  private_class_method :not_implemented_message

tdg5

%w[
  after_read
  before_eval
  after_eval
  when_started
  before_session
  after_session
].each do |hook|
  Pry.config.hooks.add_hook(hook.to_sym, "my_#{hook}_hook") do |_, _, _|
    puts "hello from #{hook}"

tdg5

# Abstract UnionList base class
class AbstractUnionList
  private :initialize

  def length
    how_many?(0)
  end

  def how_many?(counter)
    raise NotImplementedError

tdg5

# Create some special classes to facilitate tracking allocated objects.
class TrackedArray < Array; end
class TrackedString < String; end
STRANG = "a" * 5000

# Other than a few extra escapes, the code below can be understood more or less
# as is.  Any weirdness is to facilitate interpretting with/without tail-call
# optimization in a DRY manner.
KLASS = <<-CODE
class GcFriendlyTco

tdg5

# Create some special classes to facilitate tracking allocated objects.
class TrackedArray < Array; end
class TrackedString < String; end
STRANG = "a" * 5000

class ClingyObjects
  def generate(should_cling = false)
    strs = TrackedArray.new
    30000.times { strs << TrackedString.new(STRANG) }