print_and_pass: Print within pipes

In burchill/zplyr: Zach Burchill's Personal Functions

Print within pipes

Description

This function can be placed within a sequence of %>% pipes for debugging purposes. It will literally print the output of the function you specify on whatever was passed into it, and then pass it out, untouched. If you want to just print a string with no bearing on whatever is being piped, then set the .text variable to that string.

Usage

print_and_pass(.x, .f = identity, .text = NULL, ...)

Arguments

.x	Whatever is being piped down the pipeline
.f	A function, formula, or atomic vector, which will be applied to .x and whose output will be printed. print_and_pass() uses the as_mapper to turn this value into a function, so see that documentation. By default, it will just print x.
.text	When explicitly set to a non-NULL value, print_and_pass with just print that value instead. It is intended to be a string, if used.
...	Additional named arguments for whatever function is being passed in.

Value

The value of .x

Examples

df <- data.frame(x=runif(10))
new_df <- df %>%
  print_and_pass(.text="BEGIN DEBUG") %>%
  dplyr::mutate(y=x+4) %>%
  print_and_pass(~.$y) %>%
  dplyr::filter(y>4) %>%
  print_and_pass(.text="END DEBUG")

burchill/zplyr documentation built on Feb. 2, 2023, 11:01 a.m.