Hi,

I want to add a section that describes the notations used in the document.

As part of this I would like to add something about the grammar notation. Is there any write up available that describes how to read the notation?

Thanks and Regards
Dibyendu

On Wednesday, 15 May 2019 at 23:57:55 UTC, Dibyendu Majumdar wrote:
> As part of this I would like to add something about the grammar notation. Is there any write up available that describes how to read the notation?
>

Something like this:

https://golang.org/ref/spec#Notation

On Wednesday, 15 May 2019 at 23:57:55 UTC, Dibyendu Majumdar wrote:
> As part of this I would like to add something about the grammar notation. Is there any write up available that describes how to read the notation?
>

From lack of response I take it there isn't anything. So would this be correct for the grammar describing D syntax:

1. The grammar is context-free.
2. Non-terminals are in italics.
3. The right hand side of each production gives available alternatives, i.e. there is an implicit OR.
4. Terminals are shown in bold, non-italic text.
5. Optional non-terminals are suffixed by an 'opt'.

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

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)

On Thursday, 16 May 2019 at 20:23:39 UTC, Max Haughton wrote:
> The D's *grammar* is almost context free

Hi, Could you explain this further?

>
> 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)

Thank you for the link. I meant where one could use the D Grammar and literally translate it to a system like yacc or ANTLR and get a working parser. For instance in C, you can't do that I believe because you need a symbol table to resolve typedefs.

Regards

On Wednesday, 15 May 2019 at 23:57:55 UTC, Dibyendu Majumdar wrote:
> As part of this I would like to add something about the grammar notation. Is there any write up available that describes how to read the notation?
>

Interestingly I could probably just use the words by Dennis Ritchie back in 1975: https://www.bell-labs.com/usr/dmr/www/cman.pdf

Looks like even the latest C and C++ standards essentially follow that.