parse cmdline=ARGV

in scripts/lib/trollop.rb [284:408]
94 lines of code
41 McCabe index (conditional complexity)

  def parse cmdline=ARGV
    vals = {}
    required = {}

    opt :version, "Print version and exit" if @version unless @specs[:version] || @long["version"]
    opt :help, "Show this message" unless @specs[:help] || @long["help"]

    @specs.each do |sym, opts|
      required[sym] = true if opts[:required]
      vals[sym] = opts[:default]
      vals[sym] = [] if opts[:multi] && !opts[:default] 
    end

    resolve_default_short_options

    
    given_args = {}
    @leftovers = each_arg cmdline do |arg, params|
      sym = case arg
      when /^-([^-])$/
        @short[$1]
      when /^--([^-]\S*)$/
        @long[$1]
      else
        raise CommandlineError, "invalid argument syntax: '#{arg}'"
      end
      raise CommandlineError, "unknown argument '#{arg}'" unless sym

      if given_args.include?(sym) && !@specs[sym][:multi]
        raise CommandlineError, "option '#{arg}' specified multiple times"
      end

      given_args[sym] ||= {}

      given_args[sym][:arg] = arg
      given_args[sym][:params] ||= []

      
      num_params_taken = 0

      unless params.nil?
        if SINGLE_ARG_TYPES.include?(@specs[sym][:type])
          given_args[sym][:params] << params[0, 1]  
          num_params_taken = 1
        elsif MULTI_ARG_TYPES.include?(@specs[sym][:type])
          given_args[sym][:params] << params        
          num_params_taken = params.size
        end
      end

      num_params_taken
    end

    
    raise VersionNeeded if given_args.include? :version
    raise HelpNeeded if given_args.include? :help

    
    @constraints.each do |type, syms|
      constraint_sym = syms.find { |sym| given_args[sym] }
      next unless constraint_sym

      case type
      when :depends
        syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym][:long]} requires --#{@specs[sym][:long]}" unless given_args.include? sym }
      when :conflicts
        syms.each { |sym| raise CommandlineError, "--#{@specs[constraint_sym][:long]} conflicts with --#{@specs[sym][:long]}" if given_args.include?(sym) && (sym != constraint_sym) }
      end
    end

    required.each do |sym, val|
      raise CommandlineError, "option --#{@specs[sym][:long]} must be specified" unless given_args.include? sym
    end

    
    given_args.each do |sym, given_data|
      arg = given_data[:arg]
      params = given_data[:params]

      opts = @specs[sym]
      raise CommandlineError, "option '#{arg}' needs a parameter" if params.empty? && opts[:type] != :flag

      vals["#{sym}_given".intern] = true 

      case opts[:type]
      when :flag
        vals[sym] = !opts[:default]
      when :int, :ints
        vals[sym] = params.map { |pg| pg.map { |p| parse_integer_parameter p, arg } }
      when :float, :floats
        vals[sym] = params.map { |pg| pg.map { |p| parse_float_parameter p, arg } }
      when :string, :strings
        vals[sym] = params.map { |pg| pg.map { |p| p.to_s } }
      when :io, :ios
        vals[sym] = params.map { |pg| pg.map { |p| parse_io_parameter p, arg } }
      when :date, :dates
        vals[sym] = params.map { |pg| pg.map { |p| parse_date_parameter p, arg } }
      end

      if SINGLE_ARG_TYPES.include?(opts[:type])
        unless opts[:multi]       
          vals[sym] = vals[sym][0][0]
        else                      
          vals[sym] = vals[sym].map { |p| p[0] }
        end
      elsif MULTI_ARG_TYPES.include?(opts[:type]) && !opts[:multi]
        vals[sym] = vals[sym][0]  
      end
      
    end

    
    
    cmdline.clear
    @leftovers.each { |l| cmdline << l }

    
    class << vals
      def method_missing(m, *args)
        self[m] || self[m.to_s]
      end
    end
    vals
  end