Crystal をやってみた その9（ライブラリにしてみた）

前回

ライブラリにしてみた。名前はてきとうです。

使い方

プロジェクト作成

$ crystal init app testtest2

shard.yml に以下を追記

dependencies:
  esty:
    github: righ1113/esty

コマンドを打つ

$ cd testtest2
$ shards install

src/testtest2.cr に以下を書く

# $ crystal src/testtest2.cr

require "esty"

module Testtest2
  VERSION = "0.1.0"
end

# example
struct Int
  include Esty
  # factorial
  def fact
    self.<=(0).if 1, D.i(self.pred.fact.*(self))
  end
  # Fibonacci
  def fib
    self.<=(1).if (self.==(0).if 0, 1), D.i(self.pred.fib.+(self.pred.pred.fib))
  end
  # collatz (0 is inf loop)
  def collatz
    self.==(1).if [1], D.ai(self.odd?.if D.ai(self.*(3).succ.collatz.unshift(self)), D.ai(self.tdiv(2).collatz.unshift(self)))
  end
  # FizzBuzz
  def fizzbuzz
    (s = (self.%(3).==(0).if "Fizz", "").+(self.%(5).==(0).if "Buzz", "")).==("").if self.to_s, s
  end
  # zundoko
  def zdk_base(str_arr)
    rand.>(0.5).if D.ast(self.succ.zdk_base str_arr << "Zun"),
      D.ast((self.>=(4)).if D.ast(str_arr << "Doko" << "Ki-Yo-Shi!"), D.ast(0.zdk_base str_arr << "Doko"))
  end
end

# run
puts 10.fact # => 3628800

puts (0..10).to_a.map &.fib # => [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]

puts 3.collatz # => [3, 10, 5, 16, 8, 4, 2, 1]

puts (1..30).to_a.map &.fizzbuzz
# => ["1", "2", "Fizz", "4", "Buzz", "Fizz", "7", "8", "Fizz", "Buzz", "11", "Fizz", "13", "14", "FizzBuzz", "16", "17", "Fizz", "19", "Buzz", "Fizz", "22", "23", "Fizz", "Buzz", "26", "Fizz", "28", "29", "FizzBuzz"]

def zdk
  0.zdk_base [] of String
end
puts zdk # => ["Doko", "Zun", "Zun", "Zun", "Zun", "Doko", "Ki-Yo-Shi!"]

実行

$ crystal src/testtest2.cr