[Rd] callCC in 2.7.0
Dr. Ferdinand Jamitzky
f.jamitzky at gmail.com
Tue Apr 1 15:24:35 CEST 2008
Anyway something like "yield" would be very nice to have.
Would it be hard to implement?
It could be in a similar way to scala where you can define for-comprehensions.
I really miss them in R.
best wishes
ferdinand
On Tue, Apr 1, 2008 at 12:32 PM, Luke Tierney <luke at stat.uiowa.edu> wrote:
> No. First class continuations of the kind provided in scheme can be
> used as a means to implement generators, but downward-only
> continuations as currently provided in R are not sufficient for that.
> This version is intended only as a non-local exit mechanism.
>
> Best,
>
> luke
>
> On Mon, 31 Mar 2008, f.jamitzky wrote:
>
> >
> > callcc is similar to the "yield" keyword in python and c#
> > it lets you define e.g. a generator of lists of numbers.
> >
> >
> >
> >
> > Gabor Grothendieck wrote:
> >>
> >> Would anyone like to explain if callCC in R 2.7.0 gives
> >> anything that on.exit does not already provide?
> >>
> >> It seems that the exit condition once defined cannot
> >> be added to overridden whereas with on.exit multiple
> >> on.exit's add additional on.exits rather than being ignored.
> >>
> >> Is this important?
> >>
> >> ______________________________________________
> >> R-devel at r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-devel
> >>
> >>
> >
> >
>
> --
> 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 at stat.uiowa.edu
> Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
>
--
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Dr. Ferdinand Jamitzky
Leibniz Supercomputing Centre
of the Bavarian Academy of Sciences and Humanities
Boltzmannstraße 1
85748 Garching bei München
Phone: ++49-89-35831-8727
Fax: ++49-89-35831-9700
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e-mail: jamitzky at lrz.de
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