collateral (version 0.5.2)

tally: Determine how many elements contain a type of mapped side effect.

Description

Unlike summary(), the tally functions return counts of individual types of side effects. This makes them easy to use with dplyr::summarise().

Usage

tally_results(x)
tally_errors(x)
tally_warnings(x)
tally_messages(x)
tally_output(x)

Arguments

x

A ``safely_mappedorquietly_mapped` list to tally.

Value

An integer vector of length 1.

Details

Importantly, the tally functions tell you how many elements returned a type of side effect, not how many side effects were returned. Some list elements might return more than one warning, for example, and these are not counted separately.

Examples

# NOT RUN {
library(tibble)
library(dplyr)
library(tidyr)
library(collateral)

list("a", 10, 100) %>% map_safely(log) %>% tally_errors()
list(5, -12, 103) %>% map_quietly(log) %>% tally_warnings()

# if you're working with list-columns, the tally functions are useful
# in conjunction with dplyr::summarise()
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))) %>%
  summarise(
    num_results = tally_results(qlog),
    num_warnings = tally_warnings(qlog))

# }