itertools2 (version 0.1.1)

itee: Returns a list of n independent iterators from a single iterable object

Description

Constructs a list of n iterators, each of which iterates through an iterable object.

Usage

itee(object, n = 2)

Arguments

object

an iterable object

n

the number of iterables to return

Value

a list of n iterators

Details

If the object is an iterator (i.e., inherits from class iter), n deep copies of object are returned. Otherwise, object is passed to iter n times.

Examples

# Creates a list of three iterators.
# Each iterator iterates through 1:5 independently.
iter_list <- itee(1:5, n=3)

# Consumes the first iterator
unlist(as.list(iter_list[[1]])) == 1:5

# We can iterate through the remaining two iterators in any order.
iterators::nextElem(iter_list[[2]]) # 1
iterators::nextElem(iter_list[[2]]) # 2

iterators::nextElem(iter_list[[3]]) # 1
iterators::nextElem(iter_list[[3]]) # 2

iterators::nextElem(iter_list[[2]]) # 3
iterators::nextElem(iter_list[[2]]) # 4
iterators::nextElem(iter_list[[2]]) # 5

iterators::nextElem(iter_list[[3]]) # 3
iterators::nextElem(iter_list[[3]]) # 4
iterators::nextElem(iter_list[[3]]) # 5