Re: Grammar railroad diagram

Hello Bruce !

You can download the railroad generator to generate offline using Java 
here -> https://www.bottlecaps.de/rr/download/rr-1.63-java8.zip (link 
from the https://www.bottlecaps.de/rr/ui on tab Welcome).

java -jar rr.war -out:Dafny.atg.xhtml grammar.txt

Cheers !

On 6/7/21 18:51, Bruce Momjian wrote:
> On Sat, Jul  3, 2021 at 10:39:02AM +0200, Domingo Alvarez Duarte wrote:
>> I've done a experimental tool to convert bison grammars to a kind of EBNF
>> understood by https://www.bottlecaps.de/rr/ui to generate railroad diagrams see
>> bellow the converted 'postgresql-13.3/src/backend/parser/gram.y' and with some
>> hand made changes to allow view it at https://www.bottlecaps.de/rr/ui the order
>> of the rules could be changed to a better view of the railroad diagrams. Copy
>> and paste the EBNF bellow on https://www.bottlecaps.de/rr/ui tab Edit Grammar
>> then switch to the tab View Diagram.
> That is pretty cool.  I had trouble figuring out how to get it working,
> so here are the steps I used:
>
>     1.  save my attachment (created by Domingo)
>     2.  go to https://www.bottlecaps.de/rr/ui
>     3.  select "Edit Grammar"
>     4.  choose "Browse" at the bottom
>     5.  select the attachment you saved in #1
>     6.  choose "Load" at the bottom
>     7.  select "View Diagram"
>
> You can even click on the yellow boxes to see the sub-grammar.  People
> have asked for railroad diagrams in the past, and this certainly
> produces them, and "Options" allows many customizations.
>
> I tried downloading as XHTML+SVG and HTML+PNG but got an error:
>
>     HTTP Status 500 – Internal Server Error
>
>     Type Exception Report
>     
>     Message The multi-part request contained parameter data (excluding
>     uploaded files) that exceeded the limit for maxPostSize set on the
>     associated connector
>     
>     Description The server encountered an unexpected condition that
>     prevented it from fulfilling the request.
>
> It might be nice to download this output and host it on the Postgres
> website at some point.
>