Re: Clean up optional rules in grammar

On 11/11/20 10:12 AM, Peter Eisentraut wrote:
> There are a number of rules like this in the grammar:
>
> opt_foo: FOO
>         | /*EMPTY*/
> ;
>
> And there are some like this:
>
> opt_foo: FOO         {}
>         | /*EMPTY*/  {}
> ;
>
> and some even like this:
>
> %type <node> opt_foo
>
> opt_foo: FOO         { $$ = NULL; }
>         | /*EMPTY*/  { $$ = NULL; }
> ;
>
> (I mean here specifically those rules where FOO is a noise word and the
> actions are the same in each branch.)
>
> It's obviously confusing to have multiple different styles to do the
> same thing.  And these extra rules (including the empty ones) also end
> up in the output, so they create more work down the line.
>
> The attached patch cleans this up to make them all look like the first
> style.

No objections, but could we also take this opportunity to standardize
the comment itself? Even in your patch there is a mix of spacing and
casing.

My preference is /* EMPTY */. That is, uppercase with spaces, but
whatever gets chosen is fine with me.
--
Vik Fearing