meta.rb

require "rubygems"
require "johnson"

require "./visitor.rb"

js =<<-END
  function top() {
    "top docstring", { command: true }
    doSomething();
  };
  
  function justADocstring() {
    "justADocstring docstring"
    doSomething();
  }
  
  function noMeta() {
    doSomething();
  };

  Namespace = {
    nested: function() {
      "nested docstring", { command: true }
      doSomething();
    },
    
    Doubly: {
      nested: function() {
        "doubly nested docstring", { command: true }
        doSomething();
      }
    }
  };
  
  var NamespaceWithVar = {
    nested: function() {
      "nested with var docstring", { command: true }
      doSomething();
    }
  };
END

ast = Johnson.parse(js);

visitor = MetaVisitor.new do |node|
end

ast.accept(visitor)

visitor.rb

class MetaVisitor < Johnson::Visitors::EnumeratingVisitor
  attr_accessor :block
  def initialize(&block)
    @block = block
    @namespace = []
  end

  def visit_Function(o)
    name = (@namespace + [o.name]).compact.join(".")
    puts name
    super
  end

  %w{ OpEqual AssignExpr Property }.each do |type|
    define_method(:"visit_#{type}") do |o|
      @namespace.push(o.left.value)
      super
      @namespace.pop
      self
    end
  end
end