6E59: Generalized scene rulebooks

The change log mentions very briefly:

Up to now, every scene has had a “when S begins” and “when S ends” rulebook,
but there has been no way to express rules generalising about scenes. We
can now write, e.g.:

A scene can be bright or dim. A scene is usually dim. Dawn is a bright scene.

When a scene which is bright ends: say “So passes the bright [scene being changed].”

When a recurring scene begins: say “Groundhog Day!”

In addition, text defined in quotes after a scene definition becomes part of the scene description, and is printed automatically when the scene begins.

The new example Entrevaux shows how these features might be used for a scene-centric rather than location-centric kind of programming.