maps and pmaps function in the new version of purrr not works when ... in the function

[earthcli]

list %>% pmaps(fun_(x=.,y=3,...))
as above, when there is "..." in the fun_ ,the second parameter y will not be passed correctly, while the old version works well.

[czeildi]

I have a probably related issue: the function possibly does not work with the ellipsis and this behavior changed since the previous version (from 0.2.2 to 0.2.3) Here is a reprex containing a work-around as well as the issue:

library("purrr")
#> Warning: package 'purrr' was built under R version 3.4.1
# R version 3.4.0 (2017-04-21)
# purrr_0.2.3

safe_sum_explicit_param <- function(numbers) {
    possibly(
        ~ sum(numbers),
        otherwise = -Inf
    )
}

safe_sum_explicit_param(c(a = 2, b = 3))()
#> [1] 5
safe_sum_explicit_param("not a vector of numbers, error is expected")()
#> [1] -Inf

safe_sum_ellipsis_param <- function(...) {
    possibly(
        ~ sum(...),
        otherwise = -Inf
    )
}
safe_sum_ellipsis_param(a = 2, b = 3)()
#> [1] 0
# 0 means empty param list passed to ...

safe_sum_good <- function(...) {
    params <- list(...)
    possibly(
        ~ sum(unlist(params)),
        otherwise = -Inf
    )
}

safe_sum_good(a = 2, b = 3)()
#> [1] 5
safe_sum_good(a = "not a vector of numbers, error is expected")()
#> [1] -Inf

I would expect passing ... to work without any problem as it is often useful when creating general functions using purrr.

[czeildi]

I experimented with map and ... and found examples which show that the issue is probably related to the formula notation:

library("purrr")
#> Warning: package 'purrr' was built under R version 3.4.1
# R version 3.4.0 (2017-04-21)
# purrr_0.2.3

sum_with_default_formula_notation <- function(...) {
    map(1:3, ~ sum(.x, ...))
}

sum_with_default_formula_notation(a = 1000)
#> [[1]]
#> [1] 2
#> 
#> [[2]]
#> [1] 4
#> 
#> [[3]]
#> [1] 6

sum_with_default_anonymous_function <- function(...) {
    map(1:3, function(default) {sum(default, ...)})
}

sum_with_default_anonymous_function(a = 1000)
#> [[1]]
#> [1] 1001
#> 
#> [[2]]
#> [1] 1002
#> 
#> [[3]]
#> [1] 1003

sum_with_default_workaround <- function(...) {
    params <- list(...)
    map(1:3, ~ sum(.x, unlist(params)))
}

sum_with_default_workaround(a = 1000)
#> [[1]]
#> [1] 1001
#> 
#> [[2]]
#> [1] 1002
#> 
#> [[3]]
#> [1] 1003

[hadley]

Yes, if you want to use ..., you'll need to use an anonymous function. ~ is only suitable for use for simple functions.