class Gem::Requirement

def self.create input
  case input
  when Gem::Requirement then
    input
  when Gem::Version, Array then
    new input
  else
    if input.respond_to? :to_str then
      new [input.to_str]
    else
      default
    end
  end
end

def self.default
  new '>= 0'
end

def self.parse obj
  return ["=", obj] if Gem::Version === obj
  unless PATTERN =~ obj.to_s
    raise BadRequirementError, "Illformed requirement [#{obj.inspect}]"
  end
  if $1 == ">=" && $2 == "0"
    DefaultRequirement
  else
    [$1 || "=", Gem::Version.new($2)]
  end
end

def == other
  Gem::Requirement === other and to_s == other.to_s
end

def as_list # :nodoc:
  requirements.map { |op, version| "#{op} #{version}" }.sort
end

def encode_with(coder)
  coder.add 'requirements', @requirements
end

def fix_syck_default_key_in_requirements
  Gem.load_yaml
  # Fixup the Syck DefaultKey bug
  @requirements.each do |r|
    if r[0].kind_of? Gem::SyckDefaultKey
      r[0] = "="
    end
  end
end

def hash # :nodoc:
  requirements.hash
end

def init_with coder # :nodoc:
  yaml_initialize coder.tag, coder.map
end

def initialize *requirements
  requirements = requirements.flatten
  requirements.compact!
  requirements.uniq!
  if requirements.empty?
    @requirements = [DefaultRequirement]
  else
    @requirements = requirements.map! { |r| self.class.parse r }
  end
end

def marshal_dump # :nodoc:
  fix_syck_default_key_in_requirements
  [@requirements]
end

def marshal_load array # :nodoc:
  @requirements = array[0]
  fix_syck_default_key_in_requirements
end

def none?
  if @requirements.size == 1
    @requirements[0] == DefaultRequirement
  else
    false
  end
end

def prerelease?
  requirements.any? { |r| r.last.prerelease? }
end

def pretty_print q # :nodoc:
  q.group 1, 'Gem::Requirement.new(', ')' do
    q.pp as_list
  end
end

def satisfied_by? version
  raise ArgumentError, "Need a Gem::Version: #{version.inspect}" unless
    Gem::Version === version
  # #28965: syck has a bug with unquoted '=' YAML.loading as YAML::DefaultKey
  requirements.all? { |op, rv| (OPS[op] || OPS["="]).call version, rv }
end

def specific?
  return true if @requirements.length > 1 # GIGO, > 1, > 2 is silly
  not %w[> >=].include? @requirements.first.first # grab the operator
end

def to_s # :nodoc:
  as_list.join ", "
end

def to_yaml_properties
  ["@requirements"]
end

def yaml_initialize(tag, vals) # :nodoc:
  vals.each do |ivar, val|
    instance_variable_set "@#{ivar}", val
  end
  Gem.load_yaml
  fix_syck_default_key_in_requirements
end