[Rd] sapply improvements

[Martin Maechler]

>>>>> Duncan Murdoch <murdoch at stats.uwo.ca>
>>>>>     on Thu, 05 Nov 2009 06:24:24 -0500 writes:

    > On 05/11/2009 4:05 AM, Martin Maechler wrote:
    >>>>>>> "PD" == Peter Dalgaard <p.dalgaard at biostat.ku.dk> on
    >>>>>>> Thu, 05 Nov 2009 00:28:51 +0100 writes:
    >> 
    PD> William Dunlap wrote: ...
    >> >>> 
    >> >>> if (x <= 0) NA else log(x)
    >> >>> 
    >> >>> variety otherwise.
    >> >> 
    >> >> Would you only want it to coerce upwards to
    >> FUN.VALUES's >> type?  E.g., allow sapply(z, length, >>
    >> FUN.VALUE=numeric(1)) to return a numeric vector but die
    >> >> on sapply(z, function(zi)as.complex(zi[1]), >>
    >> FUN.VALUE=numeric(1)) If the latter doesn't die should it
    >> >> return a complex or a numeric vector?  (I'd say it
    >> needs >> to be numeric, but I'd prefer that it died.)
    >> 
    PD> I'd say that it should probably die on downwards
    PD> coercion. Getting a double when an integer is expected,
    PD> or complex instead of double as you indicate, is a
    PD> likely user error. If not, then the user can always
    PD> coerce explicitly inside FUN.
    >> 
    >> I agree with Peter: Do allow coercion downwards

    > You missed "not", right?  I.e. we would never coerce a
    > double down to an integer or logical, but coercion in the
    > other direction would be fine?

Yes, indeed. I missed and you are right.
Martin