A "gems" command for Pry

gems-command.rb

  command "gems", "List/search installed gems. (Optional parameter: a regexp to limit the search)" do |arg|
    gems = Gem.source_index.gems.values.group_by(&:name)
    if arg
      query = Regexp.new(arg, Regexp::IGNORECASE)
      gems = gems.select { |gemname, specs| gemname =~ query }
    end

    gems.each do |gemname, specs| 
      versions = specs.map(&:version).sort.reverse.map(&:to_s)
      versions = [bright_green(versions.first)] + 
        versions[1..-1].map{|v| green v}
               
      gemname = gemname.highlight(query) if query
      output.puts "#{gemname} (#{versions.join ', '})"
    end
    
  end