It's my guess (without, of course, bothering to look at the code) that this is
a Python-ish wrapper around SPI calls to create savepoints. It's an
interesting thought that PL/Parrot might provide features in one HLL that
aren't available in another, because one HLL provides an idiom or technique
that maps very nicely over something the database might be expected to do. For
instance languages with exception handling might find their try blocks
automatically wrapped in savepoints in PL/Parrot (whether that's a good idea
or not is something else entirely). Anyway, it's too early to do such things
now, but it's fun to consider.
--
Joshua Tolley / eggyknap
End Point Corporation
http://www.endpoint.com