vapply <- function(X, FUN, FUN.VALUE, ..., USE.NAMES = TRUE)
{
FUN <- match.fun(FUN)
if(!is.vector(X) || is.object(X)) X <- as.list(X)
.Internal(vapply(X, FUN, FUN.VALUE, USE.NAMES))
}
This is an implementor question. Basically, what happened to the '...'
args in the call to the .Internal? cf lapply:, where the ... is passed.
lapply <- function (X, FUN, ...)
{
FUN <- match.fun(FUN)
## internal code handles all vector types, including expressions
## However, it would be OK to have attributes which is.vector
## disallows.
if(!is.vector(X) || is.object(X)) X <- as.list(X)
##TODO
## Note ... is not passed down. Rather the internal code
## evaluates FUN(X[i], ...) in the frame of this function
.Internal(lapply(X, FUN, ...))
}
Now both of these functions work when extra arguments are passed, so
evidently the implementation can function whether the .Internal "call"
contains the ... or not. I found other cases, notably in S3 generic
methods where the ... is not passed down.
So, essentially, my question is whether the vapply code "should" be
changed or whether a .Internal implementation should always assume an
implicit ... regardless of the code, if the semantics requires it.
Thanks
Mick
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