R devel - Aug 2014 - `*tmp*`

Hello,

given that `*tmp*` is removed after a replacement, how can code like this work?
Is there some special handling for a variable named `*tmp*` when it comes to
make element assignments?
> x<-c(1,2)
> x[1]<-42
> `*tmp*`[1]<-7 # I would expect this one to fail
> `*tmp*`
Error: object '*tmp*' not found

Confused greetings,

Michael

-- 
Dr. Michael Haupt
Principal Member of Technical Staff
Phone: +49 331 200 7277, Fax: +49 331 200 7561
Oracle Labs
Oracle Deutschland B.V. & Co. KG, Schiffbauergasse 14, 14467 Potsdam,
Germany

On Thu, 14 Aug 2014, Michael Haupt wrote:
> Hello,
>
> given that `*tmp*` is removed after a replacement, how can code like this
work? Is there some special handling for a variable named `*tmp*` when it comes
to make element assignments?
>
>> x<-c(1,2)
>> x[1]<-42
>> `*tmp*`[1]<-7 # I would expect this one to fail
>> `*tmp*`
> Error: object '*tmp*' not found
This is a consequence of the tricks the interpreter implementation
currently plays to do complex assignments. Compiled code works
differently:
> library(compiler)
> cmpfun(function() {
+            x<-c(1,2)
+    x[1]<-42
+    `*tmp*`[1]<-7 # I would expect this one to fail
+ })()
Error in cmpfun(function() { : object '*tmp*' not found

luke
>
> Confused greetings,
>
> Michael
>
>
-- 
Luke Tierney
Chair, Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:   luke-tierney at uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu