iunique: Iterator that extracts the unique elements from an iterable...
In itertools2: itertools2: Functions creating iterators for efficient looping

Description Usage Arguments Details Value Examples

Constructs an iterator that extracts each unique element in turn from an iterable object. Order of the elements is maintained. This function is an iterator analogue to sort.

1	iunique(object)

object

an iterable object

NOTE: In order to determine whether an element is unique, a list of previous unique elements is stored. In doing so, the list can potentially become large if there are a large number of unique elements.

an iterator that returns the unique elements from object

it <- ichain(rep(1, 4), rep(2, 5), 4:7, 2)
as.list(iunique(it)) # 1 2 4 5 6 7

it2 <- iterators::iter(c('a', 'a', "A", "V"))
as.list(iunique(it2)) # a A V

x <- as.character(gl(5, 10))
it_unique <- iunique(x)
as.list(it_unique) # 1 2 3 4 5