print or display variable inside function

Question

Is there a way to print or display the value of a variable while inside a function, as opposed to printing the value outside the function after the function has been called?

I am virtually certain there is and thought the code was called reveal or something similar, but I cannot recall the correct term.

my.function <- function(x) {

  y <- x^2
 #  reveal(y)
 #  display(y)

 # desired result is to print or display here:
 # [1] 16

  cat(y)
  print(y)
  return(y)  
}

x <- 4

my.function(x)
#16[1] 16
#[1] 16

cat(y), print(y) and return(y) all print outside the function. Thank you for any advice.

EDIT

I found a similar question here:

https://stat.ethz.ch/pipermail/r-help/2002-November/027348.html

The response to that question from Peter Dalgaard was to uncheck an option called buffered output under the Misc tab. However, that does not seem to be working in my case. Perhaps the questions are unrelated.

Answer 1

I like to use the message function to print for debugging, since it seems to reach the console from whatever dark depths it might be emitting from. For example:

somefunc <- function(x) {
       message(paste('ok made it this far with x=',x))
       # some stuff to debug
       message(paste('ok made it this far with x^2=',x^2))
       # some more stuff to debug
       message(paste('ok made it to the end of the function with x^3=',x^3))
}