Constructs an iterator that computes the given function f using the
arguments from each of the iterables given in ....
Details
The iterator returned is exhausted when the shortest iterable in ...
is exhausted. Note that i_map does not recycle arguments as
Map does.
The primary difference between i_starmap and
i_map is that the former expects an iterable object
whose elements are already grouped together, while the latter case groups the
arguments together before applying the given function. The choice is a matter
of style and convenience.
Examples
pow <- function(x, y) {
x^y
}
it <- i_map(pow, c(2, 3, 10), c(5, 2, 3))
as.list(it)
#> [[1]]
#> [1] 32
#>
#> [[2]]
#> [1] 9
#>
#> [[3]]
#> [1] 1000
#>
# Similar to the above, but because the second vector is exhausted after two
# calls to `nextElem`, the iterator is exhausted.
it2 <- i_map(pow, c(2, 3, 10), c(5, 2))
as.list(it2)
#> [[1]]
#> [1] 32
#>
#> [[2]]
#> [1] 9
#>
# Another similar example but with lists instead of vectors
it3 <- i_map(pow, list(2, 3, 10), list(5, 2, 3))
nextOr(it3, NA) # 32
#> [1] 32
nextOr(it3, NA) # 9
#> [1] 9
nextOr(it3, NA) # 1000
#> [1] 1000