similar to: copying promise

Hello, I'm looking for a way to extract objects from what gets created when I Sweave with driver = weaver(). I found where the .Rdata objects are, but when I load one into R, I don't see anything that looks like the objects that were created in that code chunk. > load("/home/darstr/r_env_cache/2.11.0/AbsMeth_5/ac047940aaa9cf1a1ec09f1628b13381.RData") > ls() [1]

The last two lines of example(delayedAssign) give this: > e <- (function(x, y = 1, z) environment())(1+2, "y", {cat(" HO! "); pi+2}) > (le <- as.list(e)) # evaluates the promises $x <promise: 0x032b31f8> $y <promise: 0x032b3230> $z <promise: 0x032b3268> which contrary to the comment appears unevaluated. Is the comment wrong or is it supposed to

Hi all, The help for delayedAssign suggests that you can use substitute to access the expression associated with a promise, and the help for substitute says: "If it is a promise object, i.e., a formal argument to a function or explicitly created using ?delayedAssign()?, the expression slot of the promise replaces the symbol. But this doesn't seem to work: > a <- 1 > b <- 2

Duncan, Thank you for the clarification on how delayedAssign works. Should R-level interfaces to promise objects ever become available, I expect they would at time come in handy. On the subject of substitute and delayedAssign, I do have a follow-up question for the list. I'm trying to convert a named list of expression objects into an environment of promise objects. After conversion, each

Is there a way to raise an error condition when a promise is evaluated such that is can be evaluated again? Right now strange things happen when the evaluation fails: > delayedAssign("x", if (failed) stop("you have to initialize me first!") else foo) > foo <- "I'm foo" > failed<-TRUE > x Error: you have to initialize me first! > x

I'd like to propose a change to the R language so that calling 'parent.env<-' on a package namespace or package imports is a runtime error. Currently the documentation warns that it's dangerous behaviour and might go away: The replacement function ?parent.env<-? is extremely dangerous as it can be used to destructively change environments in ways that violate

R-devel, I used the 'substitute' function to create labels for objects inside an environment, without actually evaluating the objects, as the objects might be promises. However, I was surprised to see that 'substitute' returns the expression slot of the original promise even after the promise has been forcibly evaluated. (Doesn't the promise go away after evaluation?) This

Hi, The problem arises when I lazyLoad() the .Random.seed from a previously saved database. To simplify the process of reproducing the problem, see the example below: ## this assignment may not really make sense, but illustrates the problem delayedAssign('.Random.seed', 1L) typeof(.Random.seed) # [1] "integer" rnorm(1) # Error in rnorm(1) : # .Random.seed is not an integer

Hi, The problem arises when I lazyLoad() the .Random.seed from a previously saved database. To simplify the process of reproducing the problem, see the example below: ## this assignment may not really make sense, but illustrates the problem delayedAssign('.Random.seed', 1L) typeof(.Random.seed) # [1] "integer" rnorm(1) # Error in rnorm(1) : # .Random.seed is not an integer

The following code snippet causes R to hang. This example might be a bit contrived as I was experimenting and trying to understand promises, but uses only base R. It looks like it is looking for "not_a_variable" recursively but since it doesn't exist it goes on indefinitely. x0 <- new.env() x1 <- new.env(parent = x0) parent.env(x0) <- x1 delayedAssign("v",

Dear all, when working on a project with embedded R, I found out that R-2.0.0 causes a problem where older versions worked OK. Rf_findVar(...) causes the following error when used to find a generic function (such as print): fun = Rf_findVar(...); R_tryEval(fun, ...); Error in function (object, ...) : Invalid generic function in usemethod Alternatively, using Rf_findFun(...) seems OK in this

On Sat, 11 May 2024, Travers Ching wrote: > The following code snippet causes R to hang. This example might be a > bit contrived as I was experimenting and trying to understand > promises, but uses only base R. > > It looks like it is looking for "not_a_variable" recursively but since > it doesn't exist it goes on indefinitely. > > x0 <- new.env() > x1

Hello, ?delayedAssign presents substitute() as a way to look at the expression in the promise. However, msg <- "old" delayedAssign("x", msg) msg <- "new!" x #- new! substitute(x) #- x (was 'msg' ?) Here, we just got 'x'... shouldn't we got 'msg'? Same result when the promise is not evaluated yet: delayedAssign("x",

Hi List, I'd imagine this is a question that has been answered before, but I can't seem to track it down, sorry for the duplication if it has. I am writing an interface for a C library and want to return an S4 class from the 'constructing' method. One of the slots of the argument to be returned will be filled with one of the arguments passed to the function. My question is about

> Shield<SEXP> res(Rcpp_fast_eval(Rf_lang2(asEnvironmentSym, x), R_GlobalEnv)); The call should be protected before evaluation though. So more like: Shield<SEXP> call(Rf_lang2(asEnvironmentSym, x)); return Rcpp_fast_eval(call, R_GlobalEnv); Best, Lionel On 3/23/20, Dirk Eddelbuettel <edd at debian.org> wrote: > > > On 23 March 2020 at 17:07, Ben Bolker wrote: >

I'm not sure if this is a known peculiarity or a bug, but I stumbled across what I think is very odd behavior from delayedAssign. In the below example x switches values the first two times it is evaluated. > delayedAssign("x", {x <- 2; x+3}) > x==x [1] FALSE > delayedAssign("x", {x <- 2; x+3}) > x [1] 5 > x [1] 2 The ?delayedAssign documentation says

Is there some way of displaying the expression and evaluation environment associated with a promise? I have found the following: > # first run these two commands to set up example > e <- new.env() > delayedAssign("y", x*x, assign.env = e) > # method 1. shows expression but not evaluation environment > str(as.list(e)) List of 1 $ y: promise to language x * x >

The help files for delayedAssign and substitute both say that substitute() can be used to see the expression associated with a promise. However, I can't see how to do that. When I try the example in help file for delayedAssign I don't see substitute() extracting the promise, e.g.: > msg <- "old" > delayedAssign("x", msg) > msg <-

>>>>> Henrik Bengtsson <hb at biostat.ucsf.edu> >>>>> on Mon, 26 Jan 2015 12:41:48 -0800 writes: > On Mon, Jan 26, 2015 at 12:24 PM, Hadley Wickham <h.wickham at gmail.com> wrote: >> If it was any other environment than the global, you could use substitute: >> >> e <- new.env() >>

Hello, I'm evaluating this expression expression({ for(x in 1:5){ .Call('rh_status','x') }}) a million times from a program with R embedded in it. I have attached reproducible code that crashes with Program received signal SIGSEGV, Segmentation fault. 0x00002b499ca40a6e in R_gc_internal (size_needed=0) at memory.c:1309 1309 FORWARD_NODE(R_PPStack[i]); Current language: