Panic in R Programming Language

Our first example demonstrates how to handle unexpected errors in R. While R doesn’t have a direct equivalent to Go’s panic, we can use the stop() function to achieve similar behavior.

main <- function() {
  # We'll use stop() throughout this site to check for
  # unexpected errors. This is the only program on the
  # site designed to stop execution abruptly.
  stop("a problem")

  # A common use of stop() is to abort if a function
  # returns an error that we don't know how to
  # (or want to) handle. Here's an example of
  # stopping execution if we get an unexpected error when creating a new file.
  tryCatch({
    file.create("/tmp/file")
  }, error = function(e) {
    stop(e)
  })
}

main()

Running this program will cause it to stop execution, print an error message, and exit with a non-zero status.

When the first stop() in main is executed, the program exits without reaching the rest of the code. If you’d like to see the program try to create a temp file, comment out the first stop().

> source("error_handling.R")
Error: a problem

Note that unlike some languages which use exceptions for handling of many errors, in R it is common to use error-indicating return values and the tryCatch() function for error handling.

In R, error handling is typically done using tryCatch() or try() functions, which allow you to catch and handle errors gracefully. The stop() function is used to signal errors, similar to how panic is used in some other languages.

Remember that abruptly stopping program execution should be used sparingly, and it’s generally better to handle errors gracefully when possible.