On 2015-05-22 13:00+0100 Phil Rosenberg wrote: > Hi All > I mentioned this briefly during the previous release cycle, but we all > had more pressing things to deal with. Dealing with errors is > something we really need to get a hold on for PLPlot 6 and one of the > big drivers for considering a major API change. However, I am certain > that the reason why this has been a problem s that propagating those > errors back up through many layers of function calls is tedious and > error prone so it has been much simpler to simply call exit(). > > Here is one possible solution. We switch the core code to C++ with a C > frontend. > > I am aware some people on this list know C++ better than others, > however, the actual code changes I am suggesting are relatively small. > It may seem daunting, but I am not considering rewriting everything in > an object oriented way, I am simply advocating using two features of > C++ which will make our lives massively easier. I feel the change > would be less painful that the switch from svn to git, but with much > larger gains so please hear me out. So the following is aimed at those > of us who are a bit wary of C++ that have better C skills. If I'm > teaching my granny to suck eggs then I apologise.
Hi Phil: I am one of those active devopers without C++ skills at the present time, but I could slowly acquire those as needed just as I have done since 2000 with C, DocBook, Python, CMake, and Fortran 95 for my PLplot development needs. (Before I started working on PLplot in 2000 the only computer language I needed or used was Fortran 77.) That said, however, there are plenty of PLplot topics on my plate (e.g., build system, testing, documentation) so if I ended up leaving the development of the C++ core library to others, that might be a good division of the on-going development labour. Anyhow, I have no objections to moving to a C++ core library from personal concerns about me not knowing the language. And you did go on to describe the C++ advantages of proper handling of arrays and propagation of error conditions which sounds like a substantial benefit. However, let's be clear here the cost of that benefit is likely to be considerably higher than you are estimating now. For example, there is going to be substantial costs in terms of doxygen and DocBook documentation, and also the domestic bindings and foreign bindings (e.g., the PDL and Lisp bindings for PLplot) are of some concern. Of course, in theory you could write a perfect C wrapper library for the C++ core so bindings on that C wrapper work just as well as they do for PLplot 5. But that C wrapper would really have to be perfect and would make the bindings less efficient. Note, I don't want to emphasize that last point too much since reliability is much more important to me than speed. But at some point, I assume you will want to address that issue (e.g., for the swig-generated bindings) by ignoring the C wrapper and binding directly to the C++ core instead which adds to the cost of this change. Anyhow, I just wanted to sound a note of caution here about the amount of labour involved, but with a perfect C wrapper I see no fundamental concerns with such a change. So if you can get the other active core developers on-side with changing our core library to C++, then I certainly will not stand in the way and, in fact, if the consensus is yes, then I expect to immediately be taking an active part in this change via required changes that will be needed to the build system and the documentation. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); the Time Ephemerides project (timeephem.sf.net); PLplot scientific plotting software package (plplot.sf.net); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
