similar to: body(NULL) <- something; ditto formals() -- should not work

Hi, On 03/07/2016 09:26 AM, Martin Maechler wrote: > I'm proposing to signal an error (from R >= 3.3.0) in such > examples -- which do "work" in R 3.2.x and earlier : > >> f <- NULL; body(f) <- quote(sin(a+1)); f > function () > sin(a + 1) > <environment: 0x48f9798> > This works because formals() (the getter) works on things that are not a

With 0.63.3, try test <- function(){ fn <- function(a) print("hello") print(is.function(fn)) print(names(formals("fn")))} test() if fn is not quoted in the last line of test, it works properly. test <- function(){ fn <- function() print("hello") formals(fn) <- alist(a=,b=) return(fn)} formals(test()) now try with line 3 of test changed to

Hi, The R input/output after the following paragraph is from a session with version.string R version 2.4.0 Patched (2006-11-23 r39958). The last element, x$c, of x has no value and after the assignment of x to the formals of f, x$c does not become a formal argument of f. The second assignment does the job. It seems that x$c actually becomes the body of f after the first assignment. There is no

Dear Group: I want to create a function having a ... argument and to have the default arguments evaluated, as thus: g <- function(a, b, ...) a+b formals(g) <- alist(a=,b=2+3,...=) g function (a, b = 2 + 3, ...) a + b But I want the default argument for b to be evaluated as 5. How can this be done? Note: My real need is for a more complex expression to be evaluated for the default

On Sat, Oct 15, 2016 at 2:00 AM, Martin Maechler <maechler at stat.math.ethz.ch> wrote: >>>>>> Michael Lawrence <lawrence.michael at gene.com> >>>>>> on Wed, 12 Oct 2016 15:21:13 -0700 writes: > > > Thanks, this was what I expected. There is a desire to > > eliminate the usage of pairlist from user code, which > >

_________________________________________________________________________= ______________ Note: This e-mail is subject to the disclaimer contained at the bottom of= =20this message. _________________________________________________________________________= ______________ Just a note on the reported bug; it seems to be related to having a NULL function body. # this works > f <-

I'd like to report two bugs in the R function definitions, the first slightly problematic, the second likely unimportant. Both of these are reproducible on both Windows and Linux, R 2.0.1 First Bug: > a <- new("function") > formals(a) <- alist(a=, b=, c=, d=) > a function (a, b, c) ## the d argument disappeared! > formals(a) <- alist(a=, b=, c=, d=) > a

Dear list, I have the following function, sugar = function(fun, id = "id"){ ff <- formals(fun) if( id %in% names(ff)) stop("id is part of args(fun)") formals(fun) <- c(unlist(ff), alist(id=)) fun } which one may use on a function foo, foo = function(x){ x } sugar(foo) # results in the extended closure, function (x, id) { x } Its limitation (other

Hi all, What's the official name for the value that represents a missing argument? e.g. formals(plot)$x str(formals(plot)$x) deparse(formals(plot)$x) is.symbol(formals(plot)$x) What's the correct way to create an object like this? (for example if you are manipulating the formals of a function to add an argument with no default value, as in http://stackoverflow.com/questions/3892580/).

? Sat, 17 Feb 2024 11:15:43 -0700 "Reed A. Cartwright" <racartwright at gmail.com> ?????: > I'm wrapping a function in R and I want to record all the arguments > passed to it, including default values and missing values. This is hard if not impossible to implement for the general case because the default arguments are evaluated in the environment of the function as it

> On Jun 8, 2018, at 1:49 PM, Hadley Wickham <h.wickham at gmail.com> wrote: > > Hmmm, yes, there must be some special case in the C code to avoid > recycling a length-1 logical vector: Here is a version that (I think) handles Herve's issue of arrays having one or more 0 dimensions. subset_ROW <- function(x,i) { dims <- dim(x) index_list <-

Is there a way of getting the argument list of a function from within that function? For example, something like f <- function(x, y = 3) { fargs <- getFunctionArgList() print(fargs) ## Should be `alist(x, y = 3)' } Thanks, -roger

Dear all, I have the following problem. Given an expression object 'expr' containing a certain set of symbols (say 'a', 'b', 'c'), I would like to translate the expression object in an R function of, say, 'a', programmatically. Here an example of what I mean. Given: > expr <- expression(a+b+c) a call like: > asFunctionOf(expr, 'a',

Thanks, this was what I expected. There is a desire to eliminate the usage of pairlist from user code, which suggests the alternative of allowing for function arguments to be stored in lists. That's a much deeper change though. On Wed, Oct 12, 2016 at 12:31 PM, Henrik Bengtsson <henrik.bengtsson at gmail.com> wrote: > Michael, thanks for this info. > > I've stumbled upon

I've added a "backsolve" method to the bdsmatrix library. Per the Extending manual section 7.1 I've also added the following 3 lines along with my setMethod definitions for 2 classes. backsolve <- function(r, ...) UseMethod("backsolve") backsolve.default <- base:::backsolve formals(backsolve.default) <- c(formals(backsolve.default), alist(... = )) I've

Dear list I have a function and a vector, say f <- function(a,b){a+b} x <- c(2,3) I want to "evaluate f on x" in the sense of computing f(x[1],x[2]). I would like it to be so that I can write f(x). (I know I can write a wrapper function g <- function(x){f(x[1],x[2])}, but this is not really what I am looking for). Is there a general way doing this (programmatically)?

Dear list # I have a function ff <- function(a,b=2,c=4){a+b+c} # which I programmatically want to modify to a more specialized function in which a is replaced by 1 ff1 <- function(b=2,c=4){1+b+c} # I do as follows: vals <- list(a=1) (expr1 <- as.expression(body(ff))) expression({ a + b + c }) (expr2 <- do.call("substitute", list(expr1[[1]], vals))) { 1 +

I'm trying to build a recursive set of functions that take a set of arguments, change some of the arguments and recursively call the same (or different) function. For example here's a stupid recursive counting function that prints back all integers from x to 0 (and ignores arguments y and z) cnt <- function(x, y, z) { stopifnot(is.numeric(x)) print (x) recursionFUN <-

I'm wrapping a function in R and I want to record all the arguments passed to it, including default values and missing values. I want to be able to snoop on function calls in sourced scripts as part of a unit testing framework. I can capture the values fine, but I'm having trouble evaluating them as if `force()` had been applied to each of them. Here is a minimal example: f0 <-

I was messing around with R and I found an example R behaving oddly: a <- alist(NULL, "bob", c(3,6,2,3)) a a == 'NULL' a == "NULL" a == 'cat' If I create a list with a NULL value >a <- alist(NULL, "bob", c(3,6,2,3)) >a [[1]] NULL [[2]] [1] "bob" [[3]] c(3, 6, 2, 3) and run some tests on 'a', the '==