recover and "called from" information
I've put a fix for this in place in R-devel now. It required adding another parameter to browser(), so I'd like to test it out a while before backporting it to 2.10.0 patched. Please give it a try, and let me know if you notice anything wrong. Duncan Murdoch
On 27/10/2009 12:51 PM, Romain Francois wrote:
Hello, When using recover, the called from information is always "eval(expr, envir, enclos)", which is not particularly useful.
> f <- function( ){ g <- function(){ stop( "ouch") }; g() }
> options( error = recover )
> f()
Error in g() : ouch
Enter a frame number, or 0 to exit
1: f()
2: g()
Selection: 1
Called from: eval(expr, envir, enclos)
I'm using the following heuristic to guess if this was called from
recover and grab the actual call, and was wondering if something similar
could/should be integrated into R:
getcall <- function(){
calls <- sys.calls()
calls <- calls[ -length(calls) ]
funs <- sapply( calls, function(x) as.character(x)[1L] )
frames <- sys.frames()
frames <- frames[ -length(frames) ]
nc <- length(calls)
if( nc >= 3L &&
identical( tail(funs, 2L ), rep("eval", 2L) ) &&
identical(
paste( as.character( calls[[ nc - 1L ]] ), collapse = "--" ),
"eval--quote(browser())--sys.frame(which)" )
) {
w <- get( "which", sys.frame(nc- 2L ), inherits = FALSE )
if( typeof( w ) == "integer" && length(w) == 1L ){
return( calls[[w]] )
}
}
calls[[nc]]
}
I'd be happy to work on an internal version instead of this one in R.
Romain