itertools2 (version 0.1.1)

iunique: Iterator that extracts the unique elements from an iterable object

Description

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.

Usage

iunique(object)

Arguments

object

an iterable object

Value

an iterator that returns the unique elements from object

Details

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.

Examples

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