Bit Zeppelin Hack Party - Code Kata #2

ascii_accumulator.rb

# -*- coding:utf-8 -*-

def main(path)
  accumulator = 0
  read_ascii(path) { |char| accumulator += with_sign(to_num(char)) }
  accumulator
end

def read_ascii(path)
  File.open(path) do |f|
    while (char = f.read(1))
      yield char
    end
  end
end

def with_sign(num)
  if plus_sign? num
    num.abs
  elsif minus_sign? num
    num * -1
  else
    0
  end
end

def to_num(char)
  char.ord
end

def plus_sign?(num)
  (divisible_by? num, 2) || (divisible_by? num, 5)
end

def minus_sign?(num)
  (divisible_by? num, 3) || (divisible_by? num, 7)
end

def divisible_by?(subject, target)
  subject % target == 0
end

def validate_args
  if ARGV.length < 1
    puts "Falta: ruta al archivo"
    exit 1
  end

  if ARGV.length > 1
    puts "Ãnico argumento válido: ruta al archivo"
    exit 1
  end
end

validate_args

path = ARGV[0]
puts main(path)