Check if a component of a list is not named.

isargunnamed(x, k)

Arguments

x

a list.

k

an integer, specifies a position in x.

Details

isargunnamed(x,k) returns TRUE if the k-th component of x is not named and FALSE otherwise.

Argument x is typically a list of arguments used in a call to a function, such as the one obtained by list(...) in the body of a function definition.

If k is not positive, isargunnamed returns FALSE.

Value

TRUE or FALSE

See also

match.call in base package

Examples

li1 <- list(a=1, 2, 3) isargunnamed(li1, 1)
#> [1] FALSE
isargunnamed(li1, 2)
#> [1] TRUE
## wholly unnamed list li2 <- list(1, 2, 3) isargunnamed(li2, 1)
#> [1] TRUE
isargunnamed(li2, 2)
#> [1] TRUE
## using in a function definition f1 <- function(...){ dots <- list(...) for(i in seq(along=dots)) cat(i, isargunnamed(dots, i), "\n") } f1(1)
#> 1 TRUE
f1(a = 3, 4, c = 5)
#> 1 FALSE #> 2 TRUE #> 3 FALSE
f1(x = "a", y = "b")
#> 1 FALSE #> 2 FALSE