Over-engineered bit of Ruby to try out some code techniques and help me work on projects

workon.rb

#!/usr/bin/env ruby

require "pathname"

require "rubygems"
require "active_support/inflector"
require "spotlight"

class Symbol
  Operators = {
    :not => "!=", :gt => ">", :lt => "<", :gte => ">=", :lte => "<="
  }
  
  def method_missing(name, *args)
    if Operators.include?(name)
      @condition = Operators[name]
      return self
    end
  end
  
  def operator
    @condition || "=="
  end
  
  def to_condition
    "kMD#{to_s.classify} #{operator}"
  end
end

class String
  def spotlight_escape
    self.gsub(/(["'‘`])/, '\\\1')
  end
end

module Workon
  class << self
    attr_accessor :projects
    
    def project?(dir)
      dir = Pathname.new(dir)
      [dir.parent, dir.parent.parent].include?(Workon.projects)
    end
    
    def commands
      methods.map { |method| method[/^(.*)_command$/, 1] }.compact.sort
    end
    
    def run(command, args)
      send :"#{command}_command", args
    end
    
    def help_command(args)
      puts "usage: workon <#{commands.join(" | ")}>"
    end
    
    def search_command(args)
      project = args.first
      query = Query.new :item_display_name => project, :item_kind => "Folder"
      require "pp"
      pp query.execute
    end
  end
  
  class Query < ::Spotlight::Query
    def initialize(conditions={})
      query_string = conditions.map do |key, val|
        %{#{key.to_condition} "#{val.to_s.spotlight_escape}"c}
      end.join(" && ")
      super(query_string)
      scopes << Workon.projects.realpath
    end
    
    alias :original_execute :execute
    def execute
      original_execute.tap do |results|
        results.reject! { |result| !Workon.project?(result.get(:kMDItemPath)) }
      end
    end
  end
end

if ENV["WORKON_PROJECTS"]
  Workon.projects = Pathname.new(ENV["WORKON_PROJECTS"])
else
  $stderr.puts "Error: please set WORKON_PROJECTS."
  exit 1
end

command = ARGV[0]
if command && Workon.commands.include?(command)
  Workon.run command, ARGV[1..-1]
elsif command
  Workon.run :search, ARGV.dup
else
  Workon.run :help, ARGV[1..-1]
end