See the Class Notes link for more details about the programs.


  dslQA                         question and answer dsl
     define data structures, Quiz, etc.
     setup top-level methods, questions, right, and wrong to support the 
       DSL.
     load DSL text -- fills data structures, a quiz full of questions
     run test
  eval                          instance_eval and class_eval
     Foo.class_eval {..}           the Foo class
     Foo.instance_eval {..}        the singleton class of Foo
     define_method defines an instance method in either case
  meta_intro                    metaprogramming introduction
     def o.say_hi                  defines singleton method of object o
     "all class methods are singleton methods of instances of Class"
  dsl2                          list comprehension dsl
     From a Ruby point of view the main techniques use the instance_eval, 
     eval, send, and the method_missing methods, and function closures. New 
     instance variables are created dynamically in a local scope. The 
     domain specific language allows instance_eval to change the context of 
     evaluation while still providing access to the local scope. Each block 
     is a closure that includes the bindings in effect. When a block is 
     passed as an argument, its bindings is part of it and can be saved by 
     the caller. Evaluating :self in the binding retrieves the self object 
     that was bound to the block by the callee. The paper refers to the 
     Variable Bindings in Ruby article.
 dsl				gambling contracts
     First change DSL code to legal Ruby. Then execute it.  The bubble 
     method creates methods that just return their arguments. 
     method_missing handles the game name.
     finally the result is converted to readable English. 
  meta/cvs 			reading tables
     writes a class with the same name as a file, with getters and 
     setters for each field of a record, and with an initialize method that 
     sets each instance variable.  The read method reads the file and for 
     each record creates an instance of the class that was created.  The 
     end result is to map a file to Ruby objects.
  meta/attr1.rb			showing how attr_reader could be defined
     defines my_attr_reader as a Module instance method.  It uses 
     class_eval to add a getter method definition for each symbol.
     It is called in a class definition where self is an instance of Class
     that inherits from Module.
  meta/contracts.rb		adds software contract (see article)
     The user can define test methods and specify a contract for a method.
     When the method is defined, method_added is called which sets up the 
     contract test.  It writes a condition string of if statements, one to 
     test each condition.  It rewrites the user's method to evaluate the 
     condition string and if no exception is raised to call the original 
     method.
  finder/mf.rb,mf1.rb		finds methods given action
     Uses the method and arity methods to find all methods that return a 
     specified result when passed specified arguments.
  why/dwemthy.rb,eval.rb        creatures fight
       dwemthy1.rb,eval1.rb         simplified
     The class method, traits, gets executed when a class adds a trait 
     attribute.  It writes a getter and setter for each trait and a class 
     method for each trait that adds the trait and its value to the @traits 
     hash. It writes an  initialize method sets an instance variable for 
     each trait in the @traits hash to its value. When a Dragon class, say, 
     is defined, the @traits hash gets four values added.  When a Dragon 
     instance, say, is defined the instance variables for each trait are 
     set. The method_missing in DwemthysArray allows an array of creatures
     to fight by sending the method to the first creature in the array.
  routes/routelib.rb,routes.rb  workflow -- hard way
  routes/routedsl.rb
         easyroute/rb		workflow dsl
     Similar to the first Q&A dsl it defines the data, the Queue, Step, 
     Route classes, etc. It defines the route, step, on, etc. methods for 
     the DSL.
  routes/routedsl2.rb
         easyroute2.rb		better workflow dsl
  functional programming
     functional programming in Ruby, map-reduce, Erlang