igaiga

require "minruby"

def evaluate(tree, env)
  # pp(tree)
  case tree[0]
  when "lit"
    tree[1]
  when "+"
    evaluate(tree[1], env) + evaluate(tree[2], env)
  when "-"

igaiga

# $ ruby interp.rb test.rb
# test.rb
# plus_count=0
# x = 1+2+3
# p(plus_count) #=> 2
# x = 1+2+3
# p(plus_count) #=> 4


require "minruby"

igaiga

class A
  def foo
    "A"
  end
end
class B < A
  def foo
    "B" + super
  end
end

igaiga

# ruby 2.7.0preview2 (2019-10-22 master 02aadf1032) [x86_64-darwin18]
class Foo
  private def foo
    "foo!!"
  end
  def bar
    self.foo
  end
end

igaiga

# Rubyでメソッドと、そうではないもの（式とか）の見分け方
# methodメソッドで取得できたらメソッド

method(:p) #=> #<Method: main.p>
# ↑とれたのでメソッド

method(:for)
#=> NameError: undefined method `for' for class `#<Class:#<Object:0x00007fd82d0d22f0>>'
# ↑とれないのでメソッドではない

igaiga

# $ gem i selenium-webdriver
require "selenium-webdriver"

options = Selenium::WebDriver::Chrome::Options.new
options.add_argument('--headless')
# headless指定すると普段Chromeで指定しているフォント指定が効かなくなる

driver = Selenium::WebDriver.for :chrome, options: options
driver.get("https://igarashikuniaki.net/diary/")
driver.save_screenshot("ss.png")

igaiga

## rubyforge

$ gem sources -l
*** CURRENT SOURCES ***

http://gems.rubyforge.org/

$ gem i awesome_print

ERROR:  While executing gem ... (TypeError)

igaiga

# enc_test.txt に 日本語 を1行書いておく
File.open("enc_test.txt") do |f|
  puts out_str = f.each_line.first
  puts out_str.encoding
end
puts in_str = "中の日本語"
puts in_str.encoding

igaiga

module Hoimirable
  def hoimi
    @hp = [@hp + 20, @max_hp].min
  end
end

class Sumaltria
  include Hoimirable
end

igaiga

h1 = {}
h1.default= []
h1[:a] = h1[:a] << "hi"
h1[:b] = h1[:b] << "ho"
p h1 #=> {:a=>["hi", "ho"], :b=>["hi", "ho"]}

h2 = {}
h2.default_proc = ->(hash, key){ [] }
h2[:a] = h2[:a] << "hi"
h2[:b] = h2[:b] << "ho"