ADQL grammar validation

[olga]

On 2017-04-19 11:06, Patrick Dowler wrote:
> +1 on Dave's plan
> 
> On 19 April 2017 at 05:42, Dave Morris <dave.morris at metagrid.co.uk> 
> wrote:
>> Based on this, I would like to propose the following plan.
>> 
>> 1) We create a new WD of 2.1 with the changes from discussions since 
>> the
>> last interop.
>> 2) We add a note to say the BNF will probably be replaced in the next
>> version.
>> 3) In May we put the 2.1 draft forward as good enough for PR.
>> 
>> 4) Work on 3.0 starts now.
>> 5) We use Grégory's and Walter's work as a basis for a new PEG 
>> grammar.
>> 6) We work on increasing the coverage of SQL features in the 
>> validation
>> queries.
>> 7) We work on the tools to validate the new grammar against those 
>> queries.
>> 8) We work on updating the main text to match the new grammar.
> 
>> Is moving to PEG a good idea ?
> 
> Looks promising.
> 
>> Does moving to PEG mean a major version step, 2.x to 3.x ?
> 
> I think so, yes.
> 
>> Is 2.1 good enough for now ?
> 
> I think 2.1 is still worth the (remianing) effort. If that means
> fixing/clarifying the document and still having a broken-ish BNF then
> at least we can clearly state that.