[scromar]

I see general concept and specific implementation as being on a spectrum. If an invention is sufficiently novel/nonobvious, I believe the inventor is entitled to a patent on the general concept. However, if the invention is an incremental advance, or in a crowded field, the inventor should only be entitled to a patent on the narrower invention that is actually new, and usually this is going to be a specific implementation.

This is not to say that a patent application should not describe the invention in detail. The law requires that the patent application describe the invention in sufficient detail that one of skill in the art would be able to practice/implement the invention without "undue experimentation." This feels like the right standard to me. I believe that a software patent application that provides a functional description of the invention, even without code showing a specific implementation, that would allow a skilled programmer to implement the invention, should suffice. Whether that invention is novel/nonobvious is a separate question. The broad idea may or may not be. A narrow aspect of the idea may or may not be. You don't need actual code to figure this out.