From jeff.a.ryan at gmail.com  Tue Sep 11 17:30:14 2012
From: jeff.a.ryan at gmail.com (Jeff Ryan)
Date: Tue, 11 Sep 2012 10:30:14 -0500
Subject: [Rd] R crashes when printing a named numeric vector of a
 specific class - Bug?
In-Reply-To: <soutxv4r4p2.fsf@gmx.de>
References: <soutxv4r4p2.fsf@gmx.de>
Message-ID: <CABDUZc-uUV8ea7YvPQ2Xtj95x8Dfc0c5nLvXDBPdzvQw+ojFuA@mail.gmail.com>

print(x) in print.bar is calling print.bar again.

You need to do something like print(unclass(x))

HTH
Jeff

On Tue, Sep 11, 2012 at 9:53 AM, Basil Abou El-Komboz
<Basil.Abou-El-Komboz at stat.uni-muenchen.de> wrote:
> Dear useR's,
>
> today I stumbled over an interesting phenomenon: First, I created a
> named numeric vector with a certain class and several attributes via the
> structure() function. After that, I implemented a simple print method
> for this class. When calling this function it produces an endless loop
> of print calls until R crashes. :/
>
> What is going on here? Is this a bug or have I done something completely
> wrong? :)
>
> Below is a minimal example which reproduces the behavior. Be careful
> when calling foo() as this automatically calls print.bar() which causes
> R to crash (at least on my PC, see further informations about my system below.)
>
> Greetings,
> Basil
>
> --------------------------------------------------
>
> Minimal example:
>
> foo <- function () {
>  x <- c("A" = 1.3, "B" = 0.7, "C" = -0.3)
>  structure(x, class = "bar")
> }
>
> print.bar <- function (x, ...) {
>   print(x, ...)
> }
>
> --------------------------------------------------
>
> Further informations about my system:
>
>> version
>               _
> platform       x86_64-unknown-linux-gnu
> arch           x86_64
> os             linux-gnu
> system         x86_64, linux-gnu
> status
> major          2
> minor          15.1
> year           2012
> month          06
> day            22
> svn rev        59600
> language       R
> version.string R version 2.15.1 (2012-06-22)
> nickname       Roasted Marshmallows
>
>> sessionInfo()
>
> R version 2.15.1 (2012-06-22)
> Platform: x86_64-unknown-linux-gnu (64-bit)
>
> locale:
>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8     LC_MONETARY=en_US.UTF-8
>  [6] LC_MESSAGES=en_US.UTF-8    LC_PAPER=C                 LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> loaded via a namespace (and not attached):
> [1] compiler_2.15.1 tools_2.15.1
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel



-- 
Jeffrey Ryan
jeffrey.ryan at lemnica.com

www.lemnica.com



[Rd] R crashes when printing a named numeric vector of a specific class - Bug?
Jeff Ryan