search for: nthexpr

...<- function(..., n) ...elt(n) > > fn(stop("one"), 3*5, stop("three"), n=2) > [1] 15 > > Prior to 3.5.0, eval the appropriate component of the output > of substitute() in the appropriate environment: > > gn <- function(..., n) { > + nthExpr <- substitute(...())[[n]] > + eval(nthExpr, envir=parent.frame()) > + } > > gn(stop("one"), environment(), stop("two"), n=2) > <environment: R_GlobalEnv> > Bill, the last of these doesn't quite work, because ... can be passed down...

Hi, In some cases the number of arguments passed as ... must be determined inside a function, without evaluating the arguments themselves. I use the following construct: dotlength <- function(...) length(substitute(expression(...))) - 1L # Usage (returns 3): dotlength(1, 4, something = undefined) How can I define a method for length() which could be called directly on `...`? Or is it an

...top("one"), 3*5, stop("three"), n=2) >>> [1] 15 >>> >>> Prior to 3.5.0, eval the appropriate component of the output >>> of substitute() in the appropriate environment: >>> > gn <- function(..., n) { >>> + nthExpr <- substitute(...())[[n]] >>> + eval(nthExpr, envir=parent.frame()) >>> + } >>> > gn(stop("one"), environment(), stop("two"), n=2) >>> <environment: R_GlobalEnv> >>> >> >> Bill, the last of th...

...ating the other ... entries. > fn <- function(..., n) ...elt(n) > fn(stop("one"), 3*5, stop("three"), n=2) [1] 15 Prior to 3.5.0, eval the appropriate component of the output of substitute() in the appropriate environment: > gn <- function(..., n) { + nthExpr <- substitute(...())[[n]] + eval(nthExpr, envir=parent.frame()) + } > gn(stop("one"), environment(), stop("two"), n=2) <environment: R_GlobalEnv> Bill Dunlap TIBCO Software wdunlap tibco.com On Thu, May 3, 2018 at 7:29 AM, D?nes T?th <toth.denes at...

...lt(n) >> > fn(stop("one"), 3*5, stop("three"), n=2) >> [1] 15 >> >> Prior to 3.5.0, eval the appropriate component of the output >> of substitute() in the appropriate environment: >> > gn <- function(..., n) { >> + nthExpr <- substitute(...())[[n]] >> + eval(nthExpr, envir=parent.frame()) >> + } >> > gn(stop("one"), environment(), stop("two"), n=2) >> <environment: R_GlobalEnv> >> > > Bill, the last of these doesn't quite work, beca...

...) >> > fn(stop("one"), 3*5, stop("three"), n=2) >> [1] 15 >> >> Prior to 3.5.0, eval the appropriate component of the output >> of substitute() in the appropriate environment: >> > gn <- function(..., n) { >> + nthExpr <- substitute(...())[[n]] >> + eval(nthExpr, envir=parent.frame()) >> + } >> > gn(stop("one"), environment(), stop("two"), n=2) >> <environment: R_GlobalEnv> >> > > Bill, the last of these doesn't quite work,...

...top("one"), 3*5, stop("three"), n=2) >>> [1] 15 >>> >>> Prior to 3.5.0, eval the appropriate component of the output >>> of substitute() in the appropriate environment: >>> > gn <- function(..., n) { >>> + nthExpr <- substitute(...())[[n]] >>> + eval(nthExpr, envir=parent.frame()) >>> + } >>> > gn(stop("one"), environment(), stop("two"), n=2) >>> <environment: R_GlobalEnv> >>> >> >> Bill, the last of th...

...;three"), n=2) >>>> [1] 15 >>>> >>>> Prior to 3.5.0, eval the appropriate component of the output >>>> of substitute() in the appropriate environment: >>>> > gn <- function(..., n) { >>>> + nthExpr <- substitute(...())[[n]] >>>> + eval(nthExpr, envir=parent.frame()) >>>> + } >>>> > gn(stop("one"), environment(), stop("two"), n=2) >>>> <environment: R_GlobalEnv> >>>> >>&...

...>>>> [1] 15 > >>>> > >>>> Prior to 3.5.0, eval the appropriate component of the output > >>>> of substitute() in the appropriate environment: > >>>> > gn <- function(..., n) { > >>>> + nthExpr <- substitute(...())[[n]] > >>>> + eval(nthExpr, envir=parent.frame()) > >>>> + } > >>>> > gn(stop("one"), environment(), stop("two"), n=2) > >>>> <environment: R_GlobalEnv> > >&g...