Comment by pron

It is entirely novel. As I wrote, what makes the design revolutionary isn't the partial evaluation mechanism itself, but how the language is organised around it. It's like what made the iPhone's design revolutionary wasn't that it had a touchscreen, but that it didn't have a keypad. Partial evaluation mechanisms aren't very interesting in themselves; what's interesting is building a language around a unified partial evaluation mechanism and little else. But yes, D gets credit for adding more partial evaluation features.