[rules-dev] removing DSLs

[Wolfgang Laun]

On 31/01/2013, Mario Fusco <mario.fusco at gmail.com> wrote:
> Hi all,
>
> after a (quite long) discussion with Mark, Edson and Michael we realized
> that, to support the guided editor roundtrip without dropping our current
> DSL features, we need a new format allowing to mix plain DRL and DSL
> sentences but delimiting these last ones in a clear (and easy to recognize)
> way.
>
> Our first idea has been to not have dsl blocks and mark each dsl line with
> an initial single quote (') like in

Agreed: not a good idea.

> For the same reason we could have similar problems with many other (not too
> fancy) characters. Moreover it happens quite often to have a dsl that spans
> more lines, especially considering the - notation already remembered by
> Wolfgang in a former email of this thread.

You might have found a good one, *somewhere* in the BMP ;-)

>
> Taking count of that, I suggest to adopt a (xml-like) syntax that is a bit
> more verbose but also much more explicit and less error-prone, like in the
> following example that mixes plain drl with dsl parts:

Luckily Java doesn't permit < etc. for booleans, otherwise an expression like
  a < dsl > false
split cunningly across lines...


>
> Moreover I'd prefer to have a specific file extension for this kind of rule
> files instead of using the standard .drl one.
[snip]
>  I can't think to nothing better than .edrl
> (standing for Enriched DRL) at the moment, so I am open to any suggestion.

What about .erl?
   * 'd' is the successor of 'e', so this follows tradition (as C
follows B, or HAL follows IBM).
   * As for another connotation, see Erlkönig or Erlking,
http://en.wikipedia.org/wiki/Der_Erlk%C3%B6nig
   * Note that "Erlkönig" is firmly established as the German term for
"pretest vehicle", running camouflaged on public roads...
   * From the English translation of Goethe's famous poem, quoting the
Erlking: "Very lovely games I'll play with you".

Best
Wolfgang

>
> Any other feedback is welcome,
> Mario
>