Utility function to try and fail with grace.

Inspired from one of Hadley's functions (in plyr or something?)

failWith(
  default = NULL,
  expr,
  frame = parent.frame(),
  message = geterrmessage(),
  silent = FALSE,
  file = stderr()
)

Arguments

default	the value to return if expr fails
expr	the expression to take a shot at
frame	the frame to evaluate the expression in
message	the error message to display if expr fails. Deafults to base::geterrmessage()
silent	if TRUE, sends the error message to msg()
file	where msg sends the message

Value

the result of expr if successful, otherwise default value.

Examples

if (FALSE) {
failWith(NULL, stop("no error, just NULL"))
}