Module: NaiveCalculator::Repl

Extended by:
Repl
Included in:
Repl
Defined in:
lib/naive_calculator/repl.rb

Instance Method Summary collapse

Instance Method Details

#init ⇒ Object 



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# File 'lib/naive_calculator/repl.rb', line 20

def init
  at_exit do
    puts "\nBye!"
  end

  Signal.trap(:INT) do
  end
end

#plot(plot_data) ⇒ Object 



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# File 'lib/naive_calculator/repl.rb', line 46

def plot(plot_data)
  x_range = 90
  y_range = 10

  result = (y_range + 1).times.map {  ' ' * (x_range + 1) }

  samples = x_range.times.map do |x|
    rx = (x.to_f / x_range) * (plot_data.max_x - plot_data.min_x) + plot_data.min_x
    ry = plot_data.function.call(rx)

    [x, rx, ry]
  end

  min_y, max_y = [
    samples.min_by { |x, rx, ry| ry }.last.to_f,
    samples.max_by { |x, rx, ry| ry }.last.to_f,
  ]

  range = max_y - min_y

  samples.each do |x, rx, ry|
    scaled_y = ((ry - min_y) / range * y_range).round
    result[y_range - scaled_y][x] = 'O'
  end

  scaled_y_zero = (-min_y / range * y_range).round
  if (0...y_range).include? scaled_y_zero
    (x_range + 1).times do |x|
      result[y_range - scaled_y_zero][x] = '.' unless result[y_range - scaled_y_zero][x] == 'O'
    end
  end

  scaled_x_zero = (-plot_data.min_x.to_f / (plot_data.max_x - plot_data.min_x) * x_range).round
  if (0...x_range).include? scaled_x_zero
    (y_range + 1).times do |y|
      result[y_range - y][scaled_x_zero] = '.' unless result[y_range - y][scaled_x_zero] == 'O'
    end
  end

  result.join("\n")
end

#pretty(s) ⇒ Object 



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# File 'lib/naive_calculator/repl.rb', line 29

def pretty(s)
  case s
  when BigDecimal
    '=> ' + s.to_s('F').chomp('.0')
  when Numeric
    '=> ' + s.to_s
  when Plot
    plot(s)
  else
    s.to_s
  end
end

#pretty_print(s) ⇒ Object 



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# File 'lib/naive_calculator/repl.rb', line 42

def pretty_print(s)
  puts pretty(s)
end

#run ⇒ Object 



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# File 'lib/naive_calculator/repl.rb', line 5

def run
  init

  calculator = Calculator.new

  while input = Readline.readline("> ", true) do
    begin
      result = calculator.evaluate(input)
      pretty_print(result)
    rescue RuntimeError => e
      puts e.message
    end
  end
end