kachick

# https://twitter.com/yuroyoro/status/365050923237638144

class Array
  def ^(other)
    (self | other) - (self & other)
  end
end


[1, 2, 3] ^ [3, 4] #=> [1, 2, 4]

kachick

# https://github.com/rubinius/rubinius/blob/7866fbd80db7fe6e1de2627f5442c8abe6ce51ad/kernel/common/enumerable.rb#L113
# https://github.com/rubinius/rubinius/blob/7866fbd80db7fe6e1de2627f5442c8abe6ce51ad/kernel/common/enumerable.rb#L428


class Foo
  def each
    yield false
    yield nil
  end
end

kachick

class Time
  def jason?
    day == 13 && friday?
  end
end

kachick

Some metacharacters(\k, \g, \p, \P) crashed on some invalid examples

• valid examples not crashed

• invalid examples show warnings on YARV

ruby 1.9.3p448 (2013-06-27 revision 41675) [i686-linux]

>  ~  ruby -e '/\k/'

kachick

#!/usr/local/env ruby
# coding: us-ascii
# RLEs in Ruby
# Tested Ruby 2.0
# 2013 - Kenichi Kamiya

$VERBOSE = true

example = 'AABBCCC'.freeze #from http://d.hatena.ne.jp/notogawa/20121201/1354389374

kachick

Uninitialized regexp crashes on some methods

MRI

• ruby 1.8.7 (2012-10-12 patchlevel 371) [i686-linux]
• ruby 1.9.3p429 (2013-05-15 revision 40747) [i686-linux]

uninitialized = Regexp.allocate
uninitialized.options #=> in `options': uninitialized Regexp (TypeError)

kachick

「任意の文字セットで進数変換するライブラリ」を言語別に集める

Ruby

integer-base

• repos
• 紹介文

kachick

# coding: us-ascii
# webricksample base from: http://doc.ruby-lang.org/ja/2.0.0/library/webrick.html

$VERBOSE = true

require 'webrick'
srv = WEBrick::HTTPServer.new({ :DocumentRoot => './',
                                :BindAddress => '127.0.0.1',
                                :Port => 20080})
srv.mount('/view.cgi', WEBrick::HTTPServlet::CGIHandler, 'view.rb')

kachick

# I've written at this commit.
# https://github.com/KitaitiMakoto/pathname-common_prefix/commit/904420faed7f73a758a35eafa74151fd7724918f

class Pathname
  def start_with?(other)
    to_enum(:descend).include?(Pathname(other))
  end
end

kachick

31代まで

適当なワンライナー

ruby -e 'puts ARGF.group_by{|_|_.split.last}.map{|ken, lines|[ken, lines.count]}.sort_by(&:last).reverse.map(&:join)'

結果