Example in body() help page, unexpected warning

On Sun, 27 Dec 2009, David Winsemius wrote:

On Dec 27, 2009, at 2:07 AM, Prof Brian Ripley wrote:

Hmm, when I run example(body) I get
body> body(f) <- as.call(c(as.name("{"), e))
with no backslash.  And text help and the refman also have no  
backslash.
So, how are you doing this?  Cut-and-paste from HTML help?
Yes; that was how I entered it, but just now I entered this line  
from the keyboard and got the same result:

body(f) <- as.call(c(as.name("\{"), e))
Warning messages:
1: '\{' is an unrecognized escape in a character string
2: unrecognized escape removed from "\{"
Correct, as that is not a valid string in R ... R-devel gives an  
error.
I got a warning
David.
>
>>
>>
>> --
>>> I suspect this is yet another rendering problem with HTML help:  
>>> I've fixed quite a few since 2.10.1 was released.
>>> On Sat, 26 Dec 2009, David Winsemius wrote:
>>>> I am getting a warning when using the example s on the help page  
>>>> for body:
>>>>> f <- function(x) x^5
>>>>> body(f) <- quote(5^x)
>>>>> ## or equivalently  body(f) <- expression(5^x)
>>>>> f(3) # = 125
>>>> [1] 125
>>>>> body(f)
>>>> 5^x
>>>>> ## creating a multi-expression body
>>>>> e <- expression(y <- x^2, return(y)) # or a list
>>>>> body(f) <- as.call(c(as.name("\{"), e))
>>>> Warning messages:
>>>> 1: '\{' is an unrecognized escape in a character string
>>>> 2: unrecognized escape removed from "\{"
>>>>> f
>>>> function (x)
>>>> {
>>>> y <- x^2
>>>> return(y)
>>>> }
>>>>> f(8)
>>>> [1] 64
>>>> The text of the Details section says that:
>>>> "The bodies of all but the simplest are braced expressions, that  
>>>> is calls to {: see the ?Examples? section for how to create such  
>>>> a call."
>>>> So I am puzzled that "\{" is being removed.
>>> That is *not* what the message says: it says the backslash is  
>>> being removed.
>>>>> sessionInfo()
>>>> R version 2.10.1 RC (2009-12-09 r50695)
>>>> x86_64-apple-darwin9.8.0
>>> Please update to a released version.
>>>> locale:
>>>> [1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8
>>>> attached base packages:
>>>> [1] grid      splines   stats     graphics  grDevices utils      
>>>> datasets methods   base
>>>> other attached packages:
>>>> [1] gplots_2.7.4    caTools_1.10    bitops_1.0-4.1  gdata_2.6.1  
>>>> gtools_2.6.1
>>>> [6] hexbin_1.20.0   seqinr_2.0-7    kernlab_0.9-9    
>>>> IDPmisc_1.1.06 lattice_0.17-26
>>>> [11] Design_2.3-0    Hmisc_3.7-0     survival_2.35-7
>>>> loaded via a namespace (and not attached):
>>>> [1] cluster_1.12.1 tools_2.10.1
>>>> -- 
>>>> David Winsemius, MD
>>>> Heritage Laboratories
>>>> West Hartford, CT
>>>> _______________________________________________
>>>> R-SIG-Mac mailing list
>>>> R-SIG-Mac at stat.math.ethz.ch
>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>>> -- 
>>> Brian D. Ripley,                  ripley at stats.ox.ac.uk
>>> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
>>> University of Oxford,             Tel:  +44 1865 272861 (self)
>>> 1 South Parks Road,                     +44 1865 272866 (PA)
>>> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
>>
>> David Winsemius, MD
>> Heritage Laboratories
>> West Hartford, CT
>>
>
> -- 
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self)
> 1 South Parks Road,                     +44 1865 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595

David Winsemius, MD
Heritage Laboratories
West Hartford, CT

Example in body() help page, unexpected warning

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