messy_but_works.rb

# 
# Results:
# X adult(s), Y child(ren) and Z infant(s)
#
# rules: - 
# - pluralization hacks in case of 1 of each of them.
# - only show children and infants if they're > 0
# - at least one adult is always present
#
# examples...
# 
# 5 adults, 2 children and 1 infant
# 1 adult and 2 infants
# 2 adults and 1 child
# 1 adult


def pdf_total_in_group opts={}
  opts.default = 0

  # These could quite easily be other methods
  pluralize = lambda {|number, single, plural| "#{number} #{number == 1 ? single : plural}" }
  output_string = lambda {|number, single, plural| pluralize[number, single, plural] if number > 0 }

  a = [
    output_string[opts[:adults], "adult", "adults"],
    output_string[opts[:children], "child", "children"],
    output_string[opts[:infants], "infant", "infants"],
  ].compact

  a.size > 1 ? "#{a[0..-2].join(", ")} and #{a[-1]}" : a.first
end

pdf_total_in_group :adults => 5, :children => 2, :infants => 1 # => "5 adults, 2 children and 1 infant"
pdf_total_in_group :adults => 1, :infants => 2 # => "1 adult and 2 infants"
pdf_total_in_group :adults => 2, :children => 1 # => "2 adults and 1 child"
pdf_total_in_group :adults => 1 # => "1 adult"