Wed Dec 2 13:57:13 CET 2009

Code reps

- tuples (low-level, tree-structures, C)
- vectors (high-level, graphs, EX, GC)
- cons-lists (in terms of vectors)

For communication between apps, symbol-tagged tuples to represent ADT
constructors seems simplest.  However, the s-expression parser
produces such a description based on cons cells.

Maybe there should be a routine that flattens this, and fails on
improper lists.

tagged cons list -> tagged tuples.

Can the parser be extended to produce flat vectors directly?