FFI bridge to libruby.

ffi-ruby.rb

require 'ffi'

module FFI::Ruby
  class Value
    class << self
      extend ::FFI::Library
      ffi_lib 'ruby'

      attach_function :rb_obj_id, [:pointer], :pointer
      attach_function :rb_num2long, [:pointer], :long

      def native_type
        FFI::Type::POINTER
      end

      def from_native(value, ctx=nil)
        id =
          if value.address & 0x0f == 0xe
            value.address >> 8
          else
            rb_num2long rb_obj_id value
          end
        ObjectSpace._id2ref id
      end

      def to_native(obj, ctx=nil)
        id = obj.__id__
        case obj
        when Symbol
          FFI::Pointer.new id << 8 | 0xe
        when Fixnum, FalseClass, TrueClass, NilClass
          FFI::Pointer.new id
        else
          FFI::Pointer.new id << 1
        end
      end
    end
  end

  extend ::FFI::Library

  ffi_lib 'ruby'
  
  typedef FFI::Type::Mapped.new(Value), :value

  attach_function :rb_ary_new, [], :value
  attach_function :rb_ary_to_s, [:value], :value
  attach_function :rb_ary_includes, [:value, :value], :value

  attach_function :rb_io_puts, [:int, :pointer, :value], :value
  attach_variable :rb_cArray, :value
  attach_variable :rb_stdout, :value

  attach_function :ruby_show_version, [], :void
end