[Rd] Request: Suggestions for "good teaching" packages, esp. with C code

Duncan Murdoch murdoch.duncan at gmail.com
Wed Feb 16 13:39:46 CET 2011

On 11-02-16 7:31 AM, Martin Becker wrote:
> On 15.02.2011 22:48, David Scott wrote:
>> On 16/02/2011 7:04 a.m., Paul Johnson wrote:
>>> ...
>>> 4. We don't want gratuitous use of "return" at the end of functions.
>>> Why do people still do that?
>> Well I for one (and Jeff as well it seems) think it is good
>> programming practice. It makes explicit what is being returned
>> eliminating the possibility of mistakes and provides clarity for
>> anyone reading the code.
>> David Scott
> AFAIR (but I am not sure, maybe some expert can comment on this), there
> is a difference between using return and not using return when R code is
> called from C-code via eval(). If my memory is correct, a return()
> statement (in the R code) would abort the C function (which is trying to
> evaluate the R code, e.g., the body of a function) as well, which is
> probably not intended. So, the use of return() in R code may be quite
> disadvantageous in certain situations.

As far as I know there is no such effect.  I suspect what you saw just 
triggered a bug in the C code that had stayed hidden before.

Duncan Murdoch

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