Functions for interacting with stack and queue data structures
implemented using filehash databases.
push(db, val, ...)
mpush(db, vals, ...)
pop(db, ...)
top(db, ...)
isEmpty(db, ...)push and mpush return nothing useful; pop returns
a value from the stack/queue and deletes that value from the
stack/queue; top returns the "top" value from the stack/queue;
isEmpty returns TRUE/FALSE depending on whether
the stack/queue is empty or not. Both pop and top
signal an error if the stack/queue is empty.
an object of class "stack" or "queue"
an R object
a list of R objects
arguments passed to other methods
Roger D. Peng rpeng@jhsph.edu
Note that for mpush, if vals is not a list it will be
coerced to a list via as.list. Currently, mpush is only
implemented for "stack"s.