invoke: Invoke functions.

In purrr: Functional Programming Tools

Invoke functions.

Description

These functions were superded in purrr 0.3.0 and deprecated in purrr 1.0.0.

• invoke() is deprecated in favour of the simpler exec() function reexported from rlang. exec() evaluates a function call built from its inputs and supports dynamic dots:

  # Before:
  invoke(mean, list(na.rm = TRUE), x = 1:10)
  
  # After
  exec(mean, 1:10, !!!list(na.rm = TRUE))
  

• invoke_map() is deprecated because it's harder to understand than the corresponding code using map()/map2() and exec():

  # Before:
  invoke_map(fns, list(args))
  invoke_map(fns, list(args1, args2))
  
  # After:
  map(fns, exec, !!!args)
  map2(fns, list(args1, args2), \(fn, args) exec(fn, !!!args))
  

Usage

invoke(.f, .x = NULL, ..., .env = NULL)

invoke_map(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_lgl(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_int(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_dbl(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_chr(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_raw(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_dfr(.f, .x = list(NULL), ..., .env = NULL)

invoke_map_dfc(.f, .x = list(NULL), ..., .env = NULL)

Arguments

.f	For invoke, a function; for invoke_map a list of functions.
.x	For invoke, an argument-list; for invoke_map a list of argument-lists the same length as .f (or length 1). The default argument, list(NULL), will be recycled to the same length as .f, and will call each function with no arguments (apart from any supplied in ....
...	Additional arguments passed to each function.
.env	Environment in which do.call() should evaluate a constructed expression. This only matters if you pass as .f the name of a function rather than its value, or as .x symbols of objects rather than their values.

Examples

# was
invoke(runif, list(n = 10))
invoke(runif, n = 10)
# now
exec(runif, n = 10)

# was
args <- list("01a", "01b")
invoke(paste, args, sep = "-")
# now
exec(paste, !!!args, sep = "-")

# was
funs <- list(runif, rnorm)
funs |> invoke_map(n = 5)
funs |> invoke_map(list(list(n = 10), list(n = 5)))

# now
funs |> map(exec, n = 5)
funs |> map2(list(list(n = 10), list(n = 5)), function(f, args) exec(f, !!!args))

# or use pmap + a tibble
df <- tibble::tibble(
  fun = list(runif, rnorm),
  args = list(list(n = 10), list(n = 5))
)
df |> pmap(function(fun, args) exec(fun, !!!args))


# was
list(m1 = mean, m2 = median) |> invoke_map(x = rcauchy(100))
# now
list(m1 = mean, m2 = median) |> map(function(f) f(rcauchy(100)))

purrr documentation built on Aug. 10, 2023, 9:08 a.m.