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, ...)
an object of class "stack"
or "queue"
an R object
a list of R objects
arguments passed to other methods
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.
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.