R devel - May 2017 - stopifnot() does not stop at first non-TRUE argument

I think Herv?'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==4)
Stopifnot(2+2==5, print("Hey!!!") == "Hey!!!")
Stopifnot(2+2==4, print("Hey!!!") == "Hey!!!")
Stopifnot(T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,F,T)

> On 15 May 2017, at 15:37 , Martin Maechler <maechler at
stat.math.ethz.ch> wrote:
> 
> I'm still curious about Herv?'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

>>>>> peter dalgaard <pdalgd at gmail.com>
>>>>>     on Mon, 15 May 2017 16:28:42 +0200 writes:
    > I think Herv?'s idea was just that if switch can evaluate arguments
selectively, so can stopifnot(). But switch() is .Primitive, so does it from C.

if he just meant that, then "yes, of course" (but not so interesting).

    > 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:

Something like this, yes, that's close to what Serguei Sokol had proposed
(and of course I *do*  want to keep the current sophistication
 of stopifnot(), so this is really too simple)

    > 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==4)
    > Stopifnot(2+2==5, print("Hey!!!") == "Hey!!!")
    > Stopifnot(2+2==4, print("Hey!!!") == "Hey!!!")
    > Stopifnot(T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,F,T)


    >> On 15 May 2017, at 15:37 , Martin Maechler <maechler at
stat.math.ethz.ch> wrote:
    >> 
    >> I'm still curious about Herv?'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

However, it doesn't look much of a hassle to fuse my suggestion into the
current stopifnot: Basically, just use eval(as.name(paste0("..",i)))
instead of ll[[i]] and base the initial calculation of n on match.call() rather
than on list(...).

-pd

> On 15 May 2017, at 17:04 , Martin Maechler <maechler at
stat.math.ethz.ch> wrote:
> 
>>>>>> peter dalgaard <pdalgd at gmail.com>
>>>>>>    on Mon, 15 May 2017 16:28:42 +0200 writes:
> 
>> I think Herv?'s idea was just that if switch can evaluate arguments
selectively, so can stopifnot(). But switch() is .Primitive, so does it from C.
> 
> if he just meant that, then "yes, of course" (but not so
interesting).
> 
>> 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:
> 
> Something like this, yes, that's close to what Serguei Sokol had
proposed
> (and of course I *do*  want to keep the current sophistication
> of stopifnot(), so this is really too simple)
> 
>> 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==4)
>> Stopifnot(2+2==5, print("Hey!!!") == "Hey!!!")
>> Stopifnot(2+2==4, print("Hey!!!") == "Hey!!!")
>> Stopifnot(T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,F,T)
> 
> 
>>> On 15 May 2017, at 15:37 , Martin Maechler <maechler at
stat.math.ethz.ch> wrote:
>>> 
>>> I'm still curious about Herv?'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
> 
> 
> 
> 
> 
> 
> 
> 
-- 
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

On 05/15/2017 07:28 AM, peter dalgaard wrote:
> I think Herv?'s idea was just that if switch can evaluate arguments
selectively, so can stopifnot().
Yep.

Thanks,
H.
> 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==4)
> Stopifnot(2+2==5, print("Hey!!!") == "Hey!!!")
> Stopifnot(2+2==4, print("Hey!!!") == "Hey!!!")
> Stopifnot(T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,T,F,T)
>
>
>> On 15 May 2017, at 15:37 , Martin Maechler <maechler at
stat.math.ethz.ch> wrote:
>>
>> I'm still curious about Herv?'s idea on using  switch()  for
the
>> issue.
>
-- 
Herv? Pag?s

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