Tue Apr 2 19:12:36 EDT 2013

Lazy nodes

Yeah.. it would be nice, but it leads to too many hacks.  The code has
this strict side-effecting feel that's hard to get right by inserting
boxes everywhere..  Stumbling block is the "accumulate" form, where
it's hard to properly propagate the lazy semantics.

Basically, due to lazyness, some expressions will "grow".  If it were
just bindings, it would be easy, but it turns out there are many patch
points that make it very hard to read the code.

This needs a different approach.