search for: promise

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 express...

Hi all, It's possible to capture the expression associated with a promise (using substitute). Is there any way to capture the environment associated with a promise? Similarly, is there any way to tell if something is a promise without accidentally evaluating it? Thanks! Hadley -- RStudio / Rice University http://had.co.nz/

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 return an evaluated result but doesn't? > R.version.string # Vista [1] "R version 2.6.0 alpha (20...

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 behavior probably falls under the "...no guarantee that the resulting ex...

Hi all, It seems that there is a use case for obtaining the environment for the "top" promise. By "top", I mean following the promise chain up the call stack until hitting a non-promise. S4 data containers often mimic the API of base R data structures. This means writing S4 methods for functions that quote their arguments, like with() and subset(). The methods package directly fo...

1. Is there some way to copy a promise so that the copy has the same expression in its promise as the original. In the following we y is a promise that we want to copy to z. We want z to be a promise based on the expression x since y is a promise based on the expression x. Thus the answer to the code below is desired to be z=2 but it...

When an attribute is a delayed expression sometimes it is not forced when it is extracted. > x <- list() > attr(x, "p") <- delay(1) > x list() attr(,"p") <promise: 0x11e4bb8> > val <- attr(x, "p") > val [1] 1 > attr(x, "p") <promise: 0x11e4bb8> I am not quite sure whether the above is a bug or not but I think the following is a bug - a promise is supposed to give its value once evaluated! > eval(attr(x, &qu...

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 &gt...

Hello friends, I'm having a problem with my home server (ASUS A7V133 motherboard) which has a horrible performance with ATA disks connected to an integrated promise controller. Below you can see iozone results of the same disk connected to the primary/ secondary controller versus the promise one. Promise ATA100 controller: ========================= Version 1.02a ------Sequential Output------ --Sequential Input- --Random- -Per Chr- -...

Hi List I have a Promise SATA 300 TX ( NOT raid ) that do have RHEL4 driver, but this driver doesn?t work with CentOS4 Why? What can I do to get a driver that works? SATAII150/SATA300 TX series RHEL4 32-bit Driver http://www.promise.com/support/download/download2_eng.asp?productID=139&cate gory=all&am...

After a bunch of discussion in the core group, we have decided to deprecate the delay() function (which was introduced as "experimental" in R 0.50). This is the function that duplicates in R code the delayed evaluation mechanism (the promise) that's used in evaluating function arguments. The problem with delay() was that it was handled inconsistently (e.g. sometimes you would see an object displayed as <promise:...>, sometimes it would be evaluated); it tended to be error-prone in usage (e.g. this was the cause of the bug th...

...roducing 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 vector but of type 'promise' typeof(.Random.seed) # [1] "integer" So there must be an "attribute" "promise" somewhere attached to .Random.seed, and I cannot find it. The R function typeof() does not reveal it, but the TYPEOF() function in src/main/RNG.c says it is a 'promise'. My q...

...roducing 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 vector but of type 'promise' typeof(.Random.seed) # [1] "integer" So there must be an "attribute" "promise" somewhere attached to .Random.seed, and I cannot find it. The R function typeof() does not reveal it, but the TYPEOF() function in src/main/RNG.c says it is a 'promise'. My q...

Hello, In some weeks I'm going to reinstall some old RedHat9 based servers with Promise FastTrak TX2000 "semi-hardware" RAID1 controllers. I just tried to install CentOS 4.0 on a computer with a spare card and as usual both HDD attached to the RAID1 controller are seen separately by the installer because the specific driver for the TX2000 wasn't loaded. Nothing new he...

Dear Soeren, a couple of months ago, namely > revision 1.8 > date: 2003/05/01 06:20:50; author: sos; state: Exp; lines: +17 -2 > I'm pleased to announce that Promise is now supporting the FreeBSD > project by providing documentation (under NDA) and hardware for > testing. This commit is the first result of the cooperation, and > adds support for several of their new controllers that we didn't > support before (and probably newer would have witho...

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 > delayedAssign(&quo...

cc llvm-dev On Thu, Jul 21, 2016 at 9:57 AM, Vadim Chugunov <vadimcn at gmail.com> wrote: > Hi Gor, > Does you design support resumption with parameter(s)? (such as Python's > generator.send(x)). I suppose the "promise" could be used for passing data > both ways, but if that's the plan, please mention this explicitly in the > design doc. > Also, how is loading/storing to promise going to be lowered? > > Vadim > > On Mon, Jul 11, 2016 at 6:47 AM, Gor Nishanov via llvm-dev < > ll...

...39;Evaluate H to get ', H(1), '\n') + return(environment(NULL)) + } I thought that evaluating H would force it, so that H would be available in the environment returned by the function. But this is not so: > env <- f( function(x) x^2 ) Evaluate H to get 1 > env$H <promise: 012094D8> > env$H(1) Error: attempt to apply non-function So I tried to explicitly force it: > g <- function( H, prevEnv = NULL) { + if (!is.null(prevEnv)) H <- prevEnv$H + force(H) + return(environment(NULL)) + } but this still doesn't work: > env <- g(...

hi i am a complete newbie to xen, and i have still a problem with hda(hdc): lost interrupt coming from the 2.6.10-xen0 kernel on an asrock k7s8x board with an additional promise 100 controller(doesn''t get recognized anyway) an amd athlon 2400+ and 512 mb ram. an ideas? regards toby ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real us...

Hi all, Is it possible to determine the environment in which a promise will be evaluated? e.g. f <- function(code) { force(code) } f({ a <- 1 b <- 2 }) Is there any way to tell from within f that a and b will be created in the global environment? Thanks, Hadley -- http://had.co.nz/