On 10/08/2019 3:27 p.m., Lenth, Russell V wrote:
Hmmmm, I thought of an approach -- a kind of manual dispatch technique. My
generic is
recover_data <- function(object, ...) {
rd <- try(getS3method("recover_data", class(object)[1], envir =
.GlobalEnv, silent = TRUE))
if (!inherits(rd, "try-error"))
rd(object, ...)
else
UseMethod("recover_data")
}
and similar for emm_basis. The idea is it tries to find the method among
globally registered ones, and if so, it uses it; otherwise, the internal one is
used.
That's a bad test: class(object) might be a vector c("nomethod",
"hasmethod"). You're only looking for recover_data.nomethod, and maybe
only recover_data.hasmethod exists.
The getS3method() function won't automatically iterate through the
class, you'll need to do that yourself, for example
S3methodOrDefault <- function(object, generic, default) {
for (c in class(object)) {
rd <- try(getS3method(generic, c, envir = .GlobalEnv, silent = TRUE))
if (!inherits(rd, "try-error"))
return(rd)
}
return(default)
}
used as
S3methodOrDefault(object, "recover_data", internal_recover_data)
Duncan Murdoch
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