[Courses] [Ruby] Lesson 0: Installing, References, and your first homework assignment

[Mel Chua]

Hi, I'm Mel. This is my first class. I'm an electrical engineering 
student at Olin College in Boston, and don't know as much about coding 
as my friends seem to believe, but I'm trying to fix that. I was sort of 
the token "coder girl" in high school and tend more towards theory than 
hacking, and I'm also trying to tip that balance to the other side. I 
want to learn how to mess with things and not be afraid of blowing up my 
computer, darn it.

I've worked with C++, C, Python, and Scheme, but never got too in-depth 
with any of them, though I loved Python's 
"just-hack-it-together"-ability and the way Scheme makes you think 
differently than any other language I've seen. Ruby piqued my interest 
because I've heard it's a beautiful yet powerful little language, and 
wanted to learn more. I've been meaning to play with Ruby On Rails, so I 
figured this might be a good place to start before launching into that.

Homework the First - I tried looking at wiki.rb from the Instiki source 
code (a wiki written in Ruby - it's spiffy, and I'd like to learn how it 
works). Thankfully, it's well-commented and cleanly-written. I still 
have no idea what is going on, but here are my guesses.

This is code for something called a Word, which is a type of WikiLink. 
It's any group of letters that fits the wiki_word_pattern, whatever that 
is. If the code finds that the wiki word is escaped, it'll mark the 
entire inputted word as escaped; otherwise it marks nothing as escaped 
and cranks the entire thing through, hooking it up to a link of the same 
name. I can't tell you what individual lines of code do, though.

#---------- begin code ---------------
  # This chunk matches a WikiWord. WikiWords can be escaped
  # by prepending a '\'. When this is the case, the +escaped_text+
  # method will return the WikiWord instead of the usual +nil+.
  # The +page_name+ method returns the matched WikiWord.
  class Word < WikiLink

    attr_reader :escaped_text
   
    unless defined? WIKI_WORD
      WIKI_WORD = Regexp.new('(":)?(\\\\)?(' + 
WikiWords::WIKI_WORD_PATTERN + ')\b', 0, "utf-8")
    end

    def self.pattern
      WIKI_WORD
    end

    def initialize(match_data, content)
      super
      @textile_link_suffix, @escape, @page_name = match_data[1..3]
      if @escape
        @unmask_mode = :escape
        @escaped_text = @page_name
      else
        @escaped_text = nil
      end
      @link_text = WikiWords.separate(@page_name)
      @unmask_text = (@escaped_text || @content.page_link(@page_name, 
@link_text, @link_type))
    end

  end