"Joshua Noble" [email protected] wrote:

Hi Arran,

I created a BNF grammar for Q1. Copied it into BNF playground, pressed compile and watched as my browser crashed with a CODE_HUNG_ERROR.

I have tried to incrementally add productions until I get it to crash to find the issue and it just seems like after I create a certain number of productions the browser will crash if I press compile.

So, my plan is to just test sections of my BNF instead of the entire thing, however, the project spec states that I need to be able to copy my grammar into BNF playground and it should compile. What do I do? Or does the spec just mean to copy the augment I'm creating and not the entire 2.0 grammar?

Thanks.

I'll see if I can clarify the spec wording a bit - the intention is that you only need to provide the "augmented" parts. Anything that was already in the original Domolect grammar, you can just refer to in your submitted grammar as if it were already defined. That is, you can use Domolect 1.7 non-terminals a bit like methods in a library, and just "call" them. If you can suggest any changes to the spec to make this clearer, let me know!

The BNF playground will indeed crash if there are too many rules. So one way around that is to just write "dummy" rules for non-terminals that will be defined elsewhere – e.g. you could write

  <number> ::= 42

and use that instead of a real rule for a number.

The other possibility is to use other tools instead to validate grammars. The BNF playground uses a Node.js library, the Nearley parser, as its backend. It has the advantage that it's very flexible, and usually provides good error messages, but the disadvantage that it uses a lot of memory. It's possible to write a grammar validator as, e.g. a Linux binary, which would do some basic validation (but with worse error messages), and that's what I'll be using in Moodle. If that is something you would find useful, let me know, and I'll look at providing it for download.

Cheers

Arran