[R] Detect expired RSQLiteConnection?

[Duncan Murdoch]

Is there a test for an expired RSQLiteConnection?  For example, if I run

library(RSQLite)
f <- tempfile()
con <- dbConnect(SQLite(), f)
dbDisconnect(con)
con

then I get

> con
<Expired SQLiteConnection: DBI CON (11737, 2)>

and most operations using it give errors. (In my case I have a
persistent connection object, but if I save the workspace and then
reload it, I get the expired connection.) I'd like to detect this case.
 Do I need to use try(), or parse the result of printing it?

Duncan Murdoch