Ruby and methods with weird names

RLisp identifiers don't have to be Ruby identifiers - field-get and .. are perfectly valid in RLisp but not in Ruby. Normally that's not a problem, Ruby Symbols can contain arbitrary strings, names of RLisp variables and functions are used only inside the compiler, and define_method(:method, ...) and send(:method, ...) couldn't care less about what :method looks like stringified.

There's just one tiny problem - using them breaks Delegator and other classes which use text-based runtime code generation.

class Delegator
 def initialize(obj)
   preserved = ::Kernel.public_instance_methods(false)
   preserved -= ["to_s","to_a","inspect","==","=~","==="]
   for t in self.class.ancestors
     preserved |= t.public_instance_methods(false)
     preserved |= t.private_instance_methods(false)
     preserved |= t.protected_instance_methods(false)
     break if t == Delegator
   end
   preserved << "singleton_method_added"
   for method in obj.methods
     next if preserved.include? method
     begin
       eval <<-EOS
         def self.#{method}(*args, &block)
           begin
             __getobj__.__send__(:#{method}, *args, &block)
           rescue Exception
             $@.delete_if{|s| /:in `__getobj__'$/ =~ s} #`
             $@.delete_if{|s| /^\\(eval\\):/ =~ s}
             ::Kernel::raise
           end
         end
       EOS
     rescue SyntaxError
       raise NameError, "invalid identifier %s" % method, caller(4)
     end
   end
 end
end

Delegator iterates over all methods of an object (obj.methods), and for each of them generates and compiles a simple wrapper:

def self.#{method}(*args, &block)
 begin
   __getobj__.__send__(:#{method}, *args, &block)
 rescue Exception
   $@.delete_if{|s| /:in `__getobj__'$/ =~ s} #`
   $@.delete_if{|s| /^\\(eval\\):/ =~ s}
   ::Kernel::raise
 end
end

If Ruby had real macros like RLisp it wouldn't be a problem. Unfortunately Ruby code is generated by simple string substitution, and if method is anything else than a Ruby identifier it breaks.

In Ruby def is not accessible in any way other than through eval. We cannot use define_method(method, ...) as in Ruby 1.8 it cannot define methods which take blocks. And it has different argument-handling semantics than def, so it wouldn't work anyway.

Every use of text-based runtime code generation is a failure of language's reflection model.

It's weird how Ruby can be so well-knows for its metaprogrammability, and at the same time have most of it inaccessible through any means other than text-based eval. I think improving metaprogrammability is a much more important for future viability of Ruby than improving performance or other popular whining points.

So what can RLisp do:

• Accept that Delegator and everything that uses it like tmpfile and webrick is broken.
• Mangle all non-Ruby symbols into valid Ruby symbols. So (method foo-bar ...) would really define foo_bar etc.
• Monkey-patch Delegator to ignore such methods instead of raising an exception. Ugly.
• Monkey-patch Delegator to delegate such methods with slightly incorrect define_method instead of raising an exception.
• Improve Ruby metaprogrammability.