[erlang-questions] BNF/EBNF Grammar for Erlang

Ryan Molden <>
Mon Nov 14 16:55:07 CET 2011


Yep, it is much more clear ignoring the RHS of the :, I just didn't
realize that bit was meaningless to me and am not in the general habit
of ignoring vast swaths of what appears in the grammar file.

I also processed the YRL file to just delete all the stuff to the right
of the :, but thanks for the attachment anyhow.

Ryan
From: Richard O'Keefe
Sent: 11/13/2011 4:45 PM
To: Ryan Molden
Cc: Richard Carlsson; 
Subject: Re: [erlang-questions] BNF/EBNF Grammar for Erlang

On 12/11/2011, at 9:55 AM, Ryan Molden wrote:

> I'll assume that wasn't meant to be as condescending as it came off to me.
>
> >which is about as clear as it can get
>
> Yeah, something about
> binary_type -> '<<' '>>' : {type, ?line('$1'),binary,
> [abstract(0, ?line('$1')),
> abstract(0, ?line('$1'))]}.


>
> binary_type -> '<<' bin_base_type '>>' : {type, ?line('$1'),binary,
> ['$2', abstract(0, ?line('$1'))]}.

Read what's before the colon:
	binary_type -> '<<' '>>'.
	binary_type -> '<<' bin_base_type '>>'.

This *is* BNF, up to punctuation.
I've attached a copy of the R12B-5 grammar with the "what to build"
part stripped out.  This really is about as clear as it can get.



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