[spec] Looking for a write-up on the grammar notation

[Max Haughton]

On Thursday, 16 May 2019 at 18:48:15 UTC, Dibyendu Majumdar wrote:
> Some questions:
>
> 1. Is the grammar complete?
> 2. Is it unambiguous?
> 3. Can it be directly converted to a parser?
>
> Sorry I am not an expert in this so apologies if above is 
> stupid.
>
> Regards

I'm very rusty with the theory behind grammars:

the grammar is complete for the core language (There are some 
DIPs that change things, but AFAIK they're either within the 
existing grammar or require no modification).

The D's *grammar* is almost context free

I'm not sure what you mean for #3, but D can be parsed by parser 
generators 
(https://github.com/PhilippeSigaud/Pegged/blob/master/pegged/examples/dgrammar.d is close(?) to a D grammar for pegged).  The Source for the actual parser in dmd is recursive descent and therefore basically follows the grammar rules (In the source)