On 12/04/2012 16:54, Thomas Beale wrote: > On 12/04/2012 15:47, Athanasios Anastasiou wrote: >> >> > It's eiffel, so easy to read ;-) >> I am not familiar with Eiffel so let's just say i am glad you have >> included that comment in the beginning of the function :-D > > back to Pascal / Algol class then ;-) That's definitely not similar to Pascal! If i was to be sent back to a class for this, better make it Eiffel directly :-)
>> That last (pseudocode) ELSE is to complement the outer if...right? (or >> is it the elif?) > > hm.... some dumb rendering problem to do with tabs i guess. here is the > original: > > -- build slot_id_index in ARCH_REP_ARCHETYPE. > -- Current slot logic of include/exclude lists: > -- IF includes not empty and /= 'any' THEN > -- IF not excludes empty THEN -- excludes must = any; means not a > recommendation > -- create match list = includes constraint > -- ELSE -- it is just a recommendation;formally it means match all > -- create match list = all archetypes of compatible RM type > -- END > -- ELSEIF excludes not empty and /= 'any' THEN > -- IF not includes empty THEN -- includes must = any; means not a > recommendation > -- create match list = all achetypes - excludes constraint matchlist > -- ELSE -- just a recommendation; formally it means match all > -- create match list = all archetypes of compatible RM type > -- END > -- ELSE > -- create match list = all archetypes of compatible RM type > -- END Thank you >> >> Still there's only two cases "formal binding" (i.e. ONLY the indicated >> archetype) and recommendation (i.e. Anything of indicated TYPE but >> better if it's one of the indicated archetypes). >> >> If that's the case, maybe rule 3 should be absorbed by rule 1 in >> adl1.5.pdf p 62 ? >> * >> * > > I think the text needed some work. How about this: > > The semantics of the include and exclude lists are somewhat subtle, and > may initially be confusing. The semantics are as follows: > > * The meaning of the ?set of all archetypes? in any given environment > is evaluatable (and evaluated) to a finite set consisting of all > archetypes actually available within that environment, known as the > /current archetype set/, not some notional virtual / global set of > archetypes, or theoretically possible set. > * An include or exclude constraint may be ?substantive?, i.e. defining > a particular set of archetypes that would be matched within a given > slot, or ?open?, i.e. matching all possible archetype. > * A slot constraint may consist of a single include or exclude > constraint, or of an include / exclude pair. > * If an include or exclude constraint is present on its own, it is > understood as a recommendation, i.e. it does not constitute a formal > constraint for matching or exclusion, but tools and applications may > use the recommended match set in an intelligent way. The result set > for such an include or exclude is the whole current archetype set. > * If a substantive include or exclude constraint is present with a > corresponding open exclude or include, respectively, the substantive > constraint is considered formally binding. I think it's clearer. > BTW, these lexical rules are historical, and will be obsoleted one day - > I more or less had to construct them after 100s of archetypes that > actually assume these rules had been built! You will see further down in > the ADL 1.5 text an indication of the future, but for today, we are > stuck with the above... Oh joy. (Yes, i did notice that part in the text, it will make the constraint more strict but inserts yet more parsing). Is there a single BNF description of ADL 1.5 available from somewhere? All the best Athanasios
