collateral_mappers {collateral}R Documentation

Map over a list while capturing side effects.


map_safely(), map_quietly() and map_peacefully() are variants of purrr::map() that wrap the supplied function .f using purrr::safely() and/or purrr::quietly() in order to capture various side effects. Lists mapped in this way have an associated class added to them, allowing them to succinctly summarise captured side effects when displayed in a tibble.


map_safely(.x, .f, otherwise = NULL, quiet = TRUE, ...)

map_quietly(.x, .f, ...)

map_peacefully(.x, .f, ...)

map2_safely(.x, .y, .f, otherwise = NULL, quiet = TRUE, ...)

map2_quietly(.x, .y, .f, ...)

map2_peacefully(.x, .y, .f, ...)

pmap_safely(.l, .f, otherwise = NULL, quiet = TRUE, ...)

pmap_quietly(.l, .f, ...)

pmap_peacefully(.l, .f, ...)

future_map_safely(.x, .f, otherwise = NULL, quiet = TRUE, ...)

future_map_quietly(.x, .f, ...)

future_map_peacefully(.x, .f, ...)

future_map2_safely(.x, .y, .f, otherwise = NULL, quiet = TRUE, ...)

future_map2_quietly(.x, .y, .f, ...)

future_map2_peacefully(.x, .y, .f, ...)

future_pmap_safely(.l, .f, otherwise = NULL, quiet = TRUE, ...)

future_pmap_quietly(.l, .f, ...)

future_pmap_peacefully(.l, .f, ...)



A list or atomic vector.


A function, formula or atomic vector, as specified by purrr::as_mapper().


Default value to use when an error occurs.


Hide errors (TRUE, the default), or display them as they occur?


Other arguments supplied to purrr::map() or its variants, or to furrr::future_map() or its variants..


A list or atomic vector, of the same length as .x.


A list of lists. The length of .l determines the number of arguments that .f will be called with. List names will be used if present.


map_safely() will summarise the returned list with a fixed-width string of two (spaced) columns:

  1. If a result component is present, R appears, and

  2. If an error component is present, E appears.

If either component is missing, an underscore (⁠_⁠) appears in its place.

Similarly, map_quietly() will summarise the returned list with a fixed-width string of four (spaced) columns:

  1. If a result component is present, R appears,

  2. If an output component is present, O appears,

  3. If a messages component is present, M appears, and

  4. If a warnings component is present, W appears.

If any is missing, an underscore (⁠_⁠) appears in its place.

Variants for iterating over two or more inputs simultaneously are also provided and function identically to their purrr counterparts:

  1. map2_safely()

  2. map2_quietly()

  3. pmap_safely()

  4. pmap_quietly()

Further variants, prefixed by future_, allow safe or quiet mapping to happen in parallel if you have the furrr package installed:

  1. future_map_safely()

  2. future_map_quietly()

  3. future_map2_safely()

  4. future_map2_quietly()

  5. future_pmap_safely()

  6. future_pmap_quietly()


A list of the same length as .x. Each element of the returned list is itself a named list, structured according to the captured side effects. The Details section elaborates on these side effects.



# like map(), these can be used to iterate over vectors or lists
list("a", 10, 100) %>% map_safely(log)
list(5, -12, 103) %>% map_quietly(log)

# if you're using tibbles, you can also iterate over list-columns,
# such as nested data frames
mtcars %>%
  rownames_to_column(var = "car") %>%
  as_tibble() %>%
  select(car, cyl, disp, wt) %>%
  # spike some rows in cyl == 4 to make them fail
  mutate(wt = dplyr::case_when(
    wt < 2 ~ -wt,
    TRUE ~ wt)) %>%
  # nest and do some operations quietly()
  nest(data = -cyl) %>%
  mutate(qlog = map_quietly(data, ~ log(.$wt)))

[Package collateral version 0.5.2 Index]