Exclude "missing" objects
To be called inside a function, with a character vector of object names in that function's frame. strip.missing will return all names except those corresponding to formal arguments which were not set in the original call and which lack defaults. The output can safely be passed to get.
strip.missing( obs)
obs |
character vector of object names, often from |
Formal arguments that were not passed explicitly, but which do have defaults, will not be treated as missing; instead, they will be set equal to their evaluated defaults. This could cause problems if the defaults aren't meant to be evaluated.
Mark Bravington
funco <- function( first, second, third) {
a <- 9
return( do.call("returnList", lapply( strip.missing( ls()), as.name)))
}
funco( 1) # list( a=9, first=1)
funco( second=2) # list( a=9, second=2)
funco( ,,3) # list( a=9, third=3)
funco2 <- function( first=999) {
a <- 9
return( do.call("returnList", lapply( strip.missing( ls()), as.name)))
}
funco2() # list( a=9, first=999) even tho' "first" was not setPlease choose more modern alternatives, such as Google Chrome or Mozilla Firefox.