These routines are useful when preparing to pass objects to a Spark routine, as it is often necessary to ensure certain parameters are scalar integers, or scalar doubles, and so on.
ensure_scalar_integer(object, allow.na = FALSE, allow.null = FALSE,
  default = NULL)ensure_scalar_double(object, allow.na = FALSE, allow.null = FALSE,
  default = NULL)
ensure_scalar_boolean(object, allow.na = FALSE, allow.null = FALSE,
  default = NULL)
ensure_scalar_character(object, allow.na = FALSE, allow.null = FALSE,
  default = NULL)
An R object.
Are NA values permitted for this object?
Are NULL values permitted for this object?
If object is NULL, what value should
be used in its place? If default is specified, allow.null
is ignored (and assumed to be TRUE).