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


--
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
|- http://tr.im/BcPw : celebrating R commit #50000
|- http://tr.im/ztCu : RGG #158:161: examples of package IDPmisc
`- http://tr.im/yw8E : New R package : sos

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

Reply via email to