Convert function objects to strings/text?

Question

Has anyone converted a function in R into a string or text object?

Let's say for a simple square function, I'd want to convert to a text file:

sqfxn <- function(x){
  # Get square of x
  # Expect: 
  # > sqfxn(2)
  # > 4
  output <- x^2
  return(output)
}

Is there a function that will convert sqfxn()to a string object?

fxn_to_text <- function(x){
  # convert function x to text
}

Which will result to:

> txt_fxn <- fxn_to_txt(sqfxn)
> print(txt_fxn)
> "function(x){
  # Get square of x
  # Expect: 
  # > sqfxn(2)
  # > 4
  output <- x^2
  return(output)
  }"

Thanks!

See this is actually not exactly a duplicate because user wants to keep comments within function. But don't know how to reopen. — s_baldur, Jun 08 '20 at 09:28

score 2 · Answer 1 · answered Jun 08 '20 at 09:15

2

Using capture.output():

fun <- paste(capture.output(sqfxn), collapse = "\n")
cat(fun)
# function(x){
#   # Get square of x
#   # Expect: 
#   # > sqfxn(2)
#   # > 4
#   output <- x^2
#   return(output)
# }

answered Jun 08 '20 at 09:15

s_baldur

29,441
4
36
69

Oh okay, will try this one out. Thank you! – Edgardo Jopson Jun 08 '20 at 09:52

score 1 · Answer 2 · answered Jun 08 '20 at 09:23

1

I'm rooting for dput:

sqfxn <- function(x){
  # Get square of x
  # Expect: 
  # > sqfxn(2)
  # > 4
  output <- x^2
  return(output)
}

dput(sqfxn)

answered Jun 08 '20 at 09:23

Linards Kalvans

479
2
8

Tried dput - the problem is that the resulting object remains a function. Thank you though :) – Edgardo Jopson Jun 08 '20 at 09:54

score 0 · Answer 3 · answered Jun 08 '20 at 09:13

0

You can use body which as the name suggests returns the body of the function.

body(sqfxn)

#{
#    output <- x^2
#    return(output)
#}

However, this does not capture comments written inside the function.

answered Jun 08 '20 at 09:13

Ronak Shah

377,200
20
156
213

Convert function objects to strings/text?

3 Answers3