Writing a DSL in C++ with boost::proto

Question

Apologies for asking such an open-ended question, but I want to emulate some synthetic assembly (not for a real processor) in C++ and I want to decouple the assembly from the implementation of the simulator it runs on.

Writing a DSL or similar seems like the obvious way and I have some experience of this, having done something like it (actually a mixture between a DSL and an interpreter) in Groovy.

boost::proto seems like the obvious choice, but I find the documentation utterly impenetrable, even though, as I say, I have some grasp of the basics.

Is there any alternative tutorial or similar out there that explains - in a way that focuses on the practicalities of writing a DSL rather than the theory of ASTs etc - how to do this. Or is there an alternative? Right now I am stuck with implementing the assembly instructions as methods of classes that make up the simulator, which makes them very tightly bound and extremely difficult to maintain the code base.

Answer 1

I second the comments suggesting that you may have a badly matched XY-problem here.

Meanwhile, the best introduction to applied Boost Proto for an embedded eDSL was on Dave Abrahams' cpp-next.com blog. Sadly, that has gone off the air.

Eric Niebler, author of Boost Proto, has offerred to send people the raw dumps of those pages, on request:

The C++ community is suffering from the loss of the cpp-next.com website and all the great content that was once hosted there. In the past 2 months, I’ve gotten many questions both about the site and about the fate of my “Expressive C++” article series. In response, I will re-post my old articles on this blog. But I’m busy and it’ll take time. In the meanwhile, if you have a desperate need for a readable introduction to Boost.Proto and domain-specific embedded languages in C++, and you don’t mind reading raw markdown, email me. I’ll send you what I have.

http://ericniebler.com/2014/05/24/cpp-next-com-and-the-expressive-cxx-series-2/

In the mean time, waybackmachine has some of it, e.g.:

• http://web.archive.org/web/20120906070131/http://cpp-next.com/archive/2011/01/expressive-c-expression-optimization/
• http://web.archive.org/web/20120315111227/http://cpp-next.com/archive/2010/10/expressive-c-expression-extension-part-one/
• http://web.archive.org/web/20120430163700/http://cpp-next.com/archive/2010/10/expressive-c-expression-extension-part-two/
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