+;;; Note! You'll notice that none of the classes defined here store property
+;;; sets persistently, even though there's a `:pset' keyword argument
+;;; accepted by many of the classes' initialization methods. That's because
+;;; part of the pset protocol involves checking that there are no unused
+;;; properties, and this typically happens shortly after the appropriate
+;;; objects are constructed. It would be tempting to stash the pset at
+;;; initialization time, and then pick some property from it out later -- but
+;;; that won't work in general because an error might have been signalled
+;;; about that property. It wouldn't surprise me greatly to discover that
+;;; `most' code paths resulted in the property being looked up in time to
+;;; avoid the unused-property error, but a subtle change in circumstances
+;;; then causes a thing done on demand to be done later, leading to
+;;; irritating and misleading errors being reported to the user. So please
+;;; don't do that.
+
~mdw / sod / blobdiff