[Rd] Possible repeat{} / break function bug in R 3.4.1
Peter Bosa
Peter.Bosa at oregonmetro.gov
Wed Aug 23 22:48:05 CEST 2017
Thank you, Gentlemen...much appreciated!
----------------------------------------------------------------
peter bosa
metro
transportation research and modeling services
600 ne grand ave
portland, or 97232
peter.bosa at oregonmetro.gov
503.797.1771
metro | making a great place
www.oregonmetro.gov
________________________________________
From: Tomas Kalibera <tomas.kalibera at gmail.com>
Sent: Wednesday, August 23, 2017 12:54 AM
To: Peter Bosa
Cc: Lionel Henry; Martin Maechler; R-devel at r-project.org
Subject: Re: [Rd] Possible repeat{} / break function bug in R 3.4.1
Fixed in 73112.
If you needed to run this code in unpatched versions of R, you can
disable the problematic compiler optimization in the loop for instance
by adding "eval(NULL)" to the body of the loop. However, please do not
forget to remove this for future versions of R and specifically do not
assume this would turn off a particular compiler optimization in future
versions.
Best
Tomas
On 08/23/2017 09:24 AM, Tomas Kalibera wrote:
> It is a bug in the byte-code compiler. I will fix
> Tomas
>
> On 08/23/2017 09:22 AM, Lionel Henry wrote:
>> I don't think that's a bug. source() uses eval(), and eval() creates a
>> new function-like context frame. In a way expecting `break` to work
>> inside source() is like expecting `break` to cross stack frames:
>>
>> my_break <- function() break
>> repeat(my_break())
>>
>> Lionel
>>
>>
>>> On 23 août 2017, at 09:17, Martin Maechler
>>> <maechler at stat.math.ethz.ch> wrote:
>>>
>>>>>>>> Martin Maechler <maechler at stat.math.ethz.ch>
>>>>>>>> on Wed, 23 Aug 2017 09:10:20 +0200 writes:
>>>>>>>> Peter Bosa <Peter.Bosa at oregonmetro.gov>
>>>>>>>> on Tue, 22 Aug 2017 14:39:50 +0000 writes:
>>>>> Hello, I've noticed the following error using repeat{} / break in
>>>>> R 3.4.1 running on Windows 10 and Windows Server 2008 (both 64-bit
>>>>> environments).
>>>>> When running a repeat function, the break command causes an error
>>>>> message if the repeat command refers to code within a file, but
>>>>> does not produce an error if the code is contained within the
>>>>> repeat{} command.
>>>>> Hello, I've noticed the following error using repeat{} / break in
>>>>> R 3.4.1 running on Windows 10 and Windows Server 2008 (both 64-bit
>>>>> environments).
>>>>>
>>>>> When running a repeat function, the break command causes an error
>>>>> message if the repeat command refers to code within a file, but
>>>>> does not produce an error if the code is contained within the
>>>>> repeat{} command.
>>>>>
>>>>> For example, the following code runs fine:
>>>>>
>>>>> x <- 1
>>>>> y <- 5
>>>>>
>>>>> repeat {
>>>>> if(x < y) {
>>>>> print("No Break Dance :-(")
>>>>> x = x + 1
>>>>> } else {
>>>>> print("Break Dance!")
>>>>> break
>>>>> }
>>>>> }
>>>>>
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "Break Dance!"
>>>>> However, if I take the loop contents of the repeat{} function, and
>>>>> save them to a file (breakTest.R) that contains the following:
>>>>>
>>>>> if(x < y) {
>>>>> print("No Break Dance :-(")
>>>>> x = x + 1
>>>>> } else {
>>>>> print("Break Dance!")
>>>>> break
>>>>> }
>>>>>
>>>>> And then run the following code:
>>>>>
>>>>> x <- 1
>>>>> y <- 5
>>>>>
>>>>> repeat{
>>>>> source("./breakTest.R")
>>>>> }
>>>>>
>>>>> I get the following error:
>>>>>
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "No Break Dance :("
>>>>> [1] "Break Dance!"
>>>>> Error in eval(ei, envir) : no loop for break/next, jumping to top
>>>>> level
>>>>> This was not an issue with previous versions of R that I have
>>>>> used, including 3.3.3.
>>>>>
>>>>> Any suggestions? Is this a known bug with 3.4.1?
>>>> Thank you, Peter!
>>>> I can confirm what you are seeing (on Linux) in R version 3.4.0,
>>>> 3.4.1, and "R devel", and also that this had worked w/o a
>>>> problem in earlier versions of R, where I've looked at
>>>> R version 3.3.3 and 3.2.5.
>>>> I do think this is a bug, but it was not known till now.
>>>> For ease of use, I attach the two R files to easily reproduce.
>>>> Note I use writeLines() instead of print() as its output is "nicer".
>>>> Best regards,
>>>> Martin Maechler, ETH Zurich
>>> Trying again with the two attachment. Yes, I of all people (!!)
>>> should know that they must have an allowed MIME type; in this
>>> case text/plain !
>>>
>>> Martin
>>>
>>> ## see ./break-source_R341.R
>>> if(x < y) {
>>> writeLines("No Break Dance :-(")
>>> x <- x + 1
>>> } else {
>>> writeLines("Break Dance!")
>>> break
>>> }
>>> ## From: Peter Bosa <Peter.Bosa at oregonmetro.gov>
>>> ## To: "R-devel at r-project.org" <R-devel at r-project.org>
>>> ## Subject: [Rd] Possible repeat{} / break function bug in R 3.4.1
>>> ## Date: Tue, 22 Aug 2017 14:39:50 +0000
>>>
>>> ## Hello, I've noticed the following error using repeat{} / break in
>>> R 3.4.1 running on Windows 10 and Windows Server 2008 (both 64-bit
>>> environments).
>>>
>>> ## When running a repeat function, the break command causes an error
>>> message if the repeat command refers to code within a file, but does
>>> not produce an error if the code is contained within the repeat{}
>>> command.
>>>
>>> ## For example, the following code runs fine:
>>>
>>> x <- 1
>>> y <- 5
>>> repeat {
>>> if(x < y) {
>>> writeLines("No Break Dance :-(")
>>> x <- x + 1
>>> } else {
>>> writeLines("Break Dance!")
>>> break
>>> }
>>> }
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## Break Dance!
>>> ## >
>>>
>>> ## However, if I take the loop contents of the repeat{} function,
>>> and save
>>> ## them to a file (breakTest.R) that contains the following:
>>> ## ^^^^^^^^^^^
>>> ## __SEE THAT FILE__
>>> ## if(x < y) {
>>> ## writeLines("No Break Dance :-(")
>>> ## x = x + 1
>>> ## } else {
>>> ## writeLines("Break Dance!")
>>> ## break
>>> ## }
>>>
>>> ## And then run the following code:
>>>
>>> x <- 1
>>> y <- 5
>>> repeat{
>>> source("./breakTest.R")
>>> }
>>> cat("successfully finished\n")
>>>
>>> ## I get the following error:
>>>
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## No Break Dance :(
>>> ## Break Dance!
>>> ## Error in eval(ei, envir) : no loop for break/next, jumping to top
>>> level
>>> ## ^^^^^^^^^^^^^^^^^^^^
>>>
>>>
>>> ## This was not an issue with previous versions of R that I have
>>> used, including 3.3.3.
>>>
>>> ## MM: It does work in R 3.3.3, indeed
>>> ## -- it fails in R 3.4.0 and later
>>>
>>>
>>> ## Any suggestions? Is this a known bug with 3.4.1?
>>>
>>> ## Cheers-
>>> ## Peter
>>>
>>>
>>> ## ----------------------------------------------------------------
>>> ## peter bosa
>>> ## metro
>>> ## modeling services
>>> ## 600 ne grand ave
>>> ## portland, or 97232
>>>
>>> ## peter.bosa at oregonmetro.gov<mailto:peter.bosa at oregonmetro.gov>
>>> ## 503.797.1771
>>>
>>> ## metro | making a great place
>>> ## www.oregonmetro.gov
>>> ______________________________________________
>>> R-devel at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>> ______________________________________________
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