In R, how to make order of execution determined by vector-CodePudding

Let's say I have some variable funcorder and n functions func1, func2, func3 up to funcn. If funcorder=c(3,2,5...1) where length(funcorder)==n then I want to run my functions according to funcorder ie.

func3
func2
func5
...
func1

If this were a smaller example, say 2 functions then I could do something like

if (identical(funcorder,c(1,2)) {
  func1()
  func2()
} else {
  func2()
  func1()
}

but this doesn't seem very elegant and definitely doesn't scale. Is there a better way?

CodePudding user response：

We may use compose from purrr

library(purrr)
compose(!!!list(func1, func2, func3)[funcorder], .dir = "forward")(v1)

where 'v1' is the object to be executed with the functions in the order specified by funcorder

CodePudding user response：

You can have do.call call the functions inside lapply:

x <- 0

add1 <- function() x <<- 10*x   1
add2 <- function() x <<- 10*x   2
add3 <- function() x <<- 10*x   3
add4 <- function() x <<- 10*x   4
add5 <- function() x <<- 10*x   5

flist <- list(add1, add2, add3, add4, add5)
funcorder <- sample(1:5)
invisible(lapply(flist[funcorder], do.call, list()))
x
#> [1] 34512
funcorder
#> [1] 3 4 5 1 2

Found where I've seen this before: https://stackoverflow.com/a/7773454/9463489