[Rd] stopifnot() does not stop at first non-TRUE argument

peter dalgaard pdalgd at gmail.com
Mon May 15 16:28:42 CEST 2017

I think Hervé's idea was just that if switch can evaluate arguments selectively, so can stopifnot(). But switch() is .Primitive, so does it from C. 

I think it is almost a no-brainer to implement a sequential stopifnot if dropping to C code is allowed. In R it gets trickier, but how about this:

Stopifnot <- function(...)
  n <- length(match.call()) - 1
  for (i in 1:n)
    nm <- as.name(paste0("..",i))
    if (!eval(nm)) stop("not all true")
Stopifnot(2+2==5, print("Hey!!!") == "Hey!!!")
Stopifnot(2+2==4, print("Hey!!!") == "Hey!!!")

> On 15 May 2017, at 15:37 , Martin Maechler <maechler at stat.math.ethz.ch> wrote:
> I'm still curious about Hervé's idea on using  switch()  for the
> issue.

Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com

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