Which parts of a Ruby DSL will I need to build by hand?

Question

If I want to build a DSL in Ruby 1.9 or JRuby, will I need to do any of these stages by hand:

• Lexing
• Interpretation
• Parsing
• Just-in-time compilation

Obviously, being a programmer, I don't like to write actual code as much as I can get away with, so I'm hoping none of these steps require manual labor :)

Answer 1

It's all done using metaprogramming. You don't have to do any of the things you list. Jamis Buck has a nice blog post on Writing Domain Specific Languages using Ruby.

Answer 2

It depends on what you want. For writing an internal(read: uses ruby syntax) DSL, it is just ruby all the way down. If you want to build a DSL that doesn't use ruby syntax you could look at the treetop gem.

Jeremy Mcanally has a pretty good presentation about DSLs. He goes through both external and internal DSL stuff.