CSC302 2011S, Class 04: Ruby (3)

Overview:
* Generating methods
* An incomplete example
* Lab
* Reflection

Admin:
* Coffee and Donuts!
* Assignment 1 was returned last night.
* Assignment 2 was distributed this weekend.
* Do your best to finish labs on your own before the next class, since we may rely on them in that class.  (That's less important for the third lab in a sequence, but very important for the first two labs.)
* We're trying a new approach for questions on Chapter 3.  You can either post a question on Piazzza or you can respond to a question.  Questions should be posted by 9 p.m.  Answers should be posted by 10 p.m.
* EC for Thursday's talk on summer opportunities in CS.

Explain the negatives of Ruby.
* W/o access to a real array, it's likely that almost anything you do
  will not scale well.
* W/o careful underlying design, it's hard to distribute stuff.
* Etc.

What was the point of 2.4?
* There are lots of ways to make (or pretend to make) methods.
* Two approaches
  * define_method
  * Intercept the undefined method message
* Intercepting "undefined" does not have to be dangerous.
  You can always throw your own exception
* It may be less efficient
* How would you implement method dispatch well in Ruby
  * Hash table
  * Trie

Tate also claims that we've changed the "syntax" of Ruby
* E.g., we might write something like add_accessors field

Example:
* We might write "define a method along with precondition tests"

Reflection:
* Why did Tate design the file name the way he did?