"Eliminating Cycles in Weak Tables" is about the addition of ephemeron
tables to Lua 5.2.  It explains how Lua's tricolor mark-sweep GC is
extended to handle them, unfortunately using the O(N^2) algorithm of
Hayes 1997.  <http://www.inf.puc-rio.br/~roberto/docs/ry08-06.pdf>

"Extending Garbage Collection to Complex Data Structures" extends
ephemerons, which have a fixed GC strategy, to a new data structure
called _blobs_ that explain to the GC how they are to be processed,
thus allowing an arbitrary number of key-like and value-like pointers.
<https://www.cs.hmc.edu/~oneill/papers/Blobs-SPACE.pdf>.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
Using RELAX NG compact syntax to develop schemas is one of the simple
pleasures in life....          --Jeni Tennison