On Wed, Feb 27, 2013 at 6:37 PM, Andrei Alexandrescu < seewebsiteforem...@erdani.org> wrote:
> Hello, > > > Walter and I have had a long conversation about the next radical thing to > do to improve D's standing. Like others in this community, we believe it's > a good time to consider bootstrapping the compiler. Having the D compiler > written in D has quite a few advantages, among which taking advantages of > D's features and having a large codebase that would be its own test harness. > > By this we'd like to initiate a dialog about how this large project can be > initiated and driven through completion. Our initial basic ideas are: > > 1. Implement the dtoh standalone program that takes a D module and > generates its corresponding C++ header. > > 2. Use dtoh to initiate and conduct an incremental port of the compiler. > At given points throughout the code D code will coexist and link with C++ > code. > > 3. At a point in the future the last C++ module will be replaced with a D > module. Going forward there will be no more need for a C++ compiler to > build the compiler (except as a bootstrapping test). > > It is essential that we get support from the larger community for this. > This is a large project that should enjoy strong leadership apart from > Walter himself (as he is busy with dynamic library support which is > strategic) and robust participation from many of us. > > Please chime in with ideas on how to make this happen. > > > Thanks, > > Andrei > Having ported Boost.units to D, I can attest to this being a lot of work. I did try translating first and then refactoring the code, but that did not go well, mainly because of all the tricks and hacks employed when doing template meta-programming in C++ that did not translate well at all to D. With my first attempt I pretty much ended up with C++ code that was written in D, and that's not what I wanted. So I had to start over, refactoring and writing D code in D as I went. The problem with refactoring is that once you refactor a piece, chances are that you will need to refactor everything that depends on the code that was refactored, and that starts a domino effect. Of course, things are different with DMD, so translating first and then refactoring is probably the right way to do it. But, I don't see how we could use D's nice features without refactoring. So, I presume this is going to be done in two phases: Phase 1: direct translation to make sure everything works. Phase 2: refactoring to use D's nice features. And your three steps would be describing Phase 1. Arlen
