itakewhile {itertools2} | R Documentation |
Constructs an iterator that returns elements from an iterable object
as long as the given predicate
function returns TRUE
.
itakewhile(predicate, object)
predicate |
a function that determines whether an element is |
object |
an iterable object |
iterator object
# Filters out numbers exceeding 5
not_too_large <- function(x) {
x <= 5
}
it <- itakewhile(not_too_large, 1:100)
unlist(as.list(it)) == 1:5
# Same approach but uses an anonymous function
it2 <- itakewhile(function(x) x <= 10, seq(2, 100, by=2))
unlist(as.list(it2)) == c(2, 4, 6, 8, 10)