My presentation in Ruby Athens Meeting @ oslab.teipir.gr

1. Metaprogramming in Ruby
Creating languages in just a sec!
http://jon.is.emotionull.com

2. Creating a language
 Parsers from scratch
 Bison/yacc/lex
 Metaprogramming FTW!

3. Hacko!
 Example
// this is a test (example.hacko)
include ”stdio”
main {
printf ”Hello Mr. %s !”, ”Jon”
}

4. Bow to the masters
 Lisp
 Scheme
 Forth
 Smalltalk

5. Thinking again the problem
 Code as data
 Self modifying code
 Dynamic adding/removing classes/functions
 Describe the problem, don't solve it!

6. Metaprogramming in the wild
 Web frameworks (Ruby On Rails)
 A.I
 DSL
 Configuration files
 ...

7. But, hooooow???
 Function pointers (C,C++)
 Open classes (Ruby)
 Metaclasses (Python)
 Lists (Lisp/Scheme/Clojure)

8. Speed penalty – Not always
 Premature optimization
 Fast and smart VM (JVM)
 Bottleneck is somewhere else
 You are not smart enough. Deal with it!

9. Hacko!
 Implemented in ~ 10 minutes
 Looks like C
 Feels like C
 FULLY extensible
 Trivial to add new libraries
 You can use available Ruby libs
 VM ~ 25 lines!

10.
Thank for watching! Questions?
http://jon.is.emotionull.com
jon@emotionull.com