Thanks to Stavros for the report. This should now be fixed in R-devel.
luke
On Wed, 11 Mar 2009, l...@stat.uiowa.edu wrote:
Looks like an infinite recursion in R_isMissing, which I think may be
turned into an infinite loop if the C compiler is doing tail call
optimization. I need to understand why this is written the way it is
and also why another case that I would expect to also have this
problem does not before identifying the appropriate fix.
luke
On Tue, 10 Mar 2009, Peter Dalgaard wrote:
Stavros Macrakis wrote:
Tested in: R version 2.8.1 (2008-12-22) / Windows
Recursive default argument references normally give nice clear errors.
In the first set of examples, you get the error:
Error in ... :
promise already under evaluation: recursive default argument
reference or earlier problems?
(function(a = a) a ) ()
(function(a = a) c(a) ) ()
(function(a = a) a[1] ) ()
(function(a = a) a[[1]] ) ()
(function(a = a) a$x ) ()
(function(a = a) mean(a) ) ()
(function(a = a) sort(a) ) ()
(function(a = a) as.list(a) ) ()
But in the following examples, R seems not to detect the 'promise
already under evaluation' condition and instead gets a stack overflow,
with the error message:
Error: C stack usage is too close to the limit
(function(a = a) (a) ) ()
(function(a = a) -a ) ()
(function(a = a) var(a) ) ()
(function(a = a) sum(a) ) ()
(function(a = a) is.vector(a) ) ()
(function(a = a) as.numeric(a) ) ()
I don't understand why the two sets of examples behave differently.
Ouch!!!
This shouldn't happen, I'm pretty sure. In particular not the apparently
unstoppable loop under Linux. Thanks for pointing it out.
--
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: l...@stat.uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
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