On Thu, Apr 14, 2011 at 12:43 AM, Christian Gunning <x...@unm.edu> wrote: > On Tue, Apr 12, 2011 at 11:07 PM, Romain Francois > <rom...@r-enthusiasts.com> wrote: >>> >>> Just to clarify -- does your plan include storing user-modified >>> fields and properties in objects? E.g. below, modtest with the msg >>> set? >> >> yes. Although the way I see it, this will require more work for the >> developper, who would have to provide a serialization/deserialization couple >> for his/her classes. >> >> This is a nice goal for a future version. > > Am I naive to think that a 1-to-1 mapping between C++ object fields & > properties and an S4 object might make sense? This reduces the module > developer's problem of serial/deserialization to 1) writing a > constructor (and perhaps with validator) that takes an S4 object, and > 2) writing a finalizer that populates a specified S4 object in the > user's environment, tears down the C++ object (as per R Exts manual), > and let's save() do the rest? > > It seems that, in theory, there's a canonical mapping between the > names/types of fields/properties exposed in the RCPP_MODULE call and > the proposed S4 object. The main gotcha I see here is that any > variable within a C++ object *not* exposed as a field/property must be > viewed as a const to ensure consistency of the C++ object between > write and re-construct... > > If this is off-base, feel free to ignore or point out good reading material :)
I don't think it is off-base. I was planning something very similar to that except that not every field/property would be saved. I have classes in which many of the properties are calculated on the fly and I don't need to save those. I just need to save enough information to create the object again. This approach would run into trouble if there were data fields in the C++ object that could not be expressed as R objects. However, it seems to me that if the C++ object can be generated from R objects in the first place you should be able to serialize enough information to reconstruct it. _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
