A few last words on this. It is easy for JSON based archetype repository to cooperate with an ADL based repository. Serializing of an AOM structure to ADL is very easy to do, this counts for the DADL and CADL part. The other way around, to convert the ADL definition part to JSON is harder, that involves the parser-code and grammars which are hard to maintain.
It is fragile code. I remember how hard it was to get stable grammars ready, about two years ago, and they are also hard to test. You can only test the grammar and the generated code after having written thousands of lines derived code and test that. This is not unit-testing. There is a lot of untested code in a parser. I know from own experience, I already wrote a few times an ADL parser, also other parsers, in Java and golang, it takes a year or more. Pieter is working two years on it, of course not every day, but still. It is really a lot of complex code. I remember a year ago he was using a visitor pattern, now he left that. That was quite a big change. While doing it he finds out, and he does a very good job. He is a very good programmer but with a difficult task. And even small updates in a grammar can cause great code change, many difficulties. It does, in my opinion, not belong in a modern programming environment where simplicity, maintainability and testability are important goals. Only changing a few simple paradigms can make thousands of lines of code difference. The elegance of proven technology of worldwide programming effort over many years. The simplicity of JSON guarantees easy controllable and maintainable (sustainable) code. But, as said, for purpose of readability is it easy to serialize to ADL code, if that is an argument. Why do I write all this. I am writing a generic multi purpose BMM/AOM kernel as a hobby project, I work an hour a day on it, sometimes less, I have a job also. I do not want to write an ADL parser because I don't need it. It saves months of work. The code I write, which can also serve OpenEhr or ISO13606 or CIMI in any version, or accountancy software or many other can be read by a novice programmer, so simple it is. And I think that is how code should be. Easy to test, easy to debug, easy to read, easy to understand. That is my story, I wanted to see how other people think about these ideas, thanks for sharing your opinions. Best regards Bert Sent from my Xperia™ by Sony smartphone ---- Bert Verhees wrote ---- > > >Sent from my Xperia™ by Sony smartphone > >---- Original Message ---- >Subject: Re: JSON for definitions-notation >Sent: 15 Feb 2019 22:46 >From: Bert Verhees <[email protected]> >To: Pieter Bos <[email protected]> >Cc: > >Not many people find archetypes readable. I can read them and I have done that >many times, but most modelers I know are lost in a second when they see ADL >text, I have seen that many times too. But it is more readable than Xml or >JSON, I agree. > >For readability I would like to promote a documentation protocol, modeling >tooling should take care for that. That should not be the purpose of an >archetype. > >The archetypes in code are for machine processing, that should be the main >purpose, and this purpose should be exercised to a maximum of simplicity and >efficiency. > >I was thinking about the type information ADL has, if it has function in >validating datasets. > >I don't think so, and I think it can be omitted. For validating-purpose it is >not needed. >An archetype is a tree of properties to properties ending via cardinality to >leaf nodes. That is the information that is needed and JSON can deliver that >without diverging from the object dump idea. All that information is already >in AOM. This has as result that archetypes can be read in AOM without need of >parsing. > >I was also thinking about the name-convention, but that is a reference model >(BMM) issue. The naming convention in the reference model will be used in >datasets. > >BMM is very powerful, it extends the purpose of reference models and >archetypes to virtually every domain, also OpenEhr 😉. > >It is in fact a wonderful invention, especially in combination with NoSql >databases, but it needs a simplicity overhauling for efficiency and general >connection to programming eco systems or standards can be achieved by using >its conventions. > >Bert > >Sent from my Xperia™ by Sony smartphone > >---- Pieter Bos wrote ---- > >>Archie offers a json serializer and deserializer. For Odin they are present >>as well, but has not been tested with archetypes, may need a small bit of >>work. Yaml should be a matter of adding a dependency and configuring it. >>We're still working on XML - the bindings are there and it works, but the AOM >>schemas have not been finished yet so there will be changes, see the >>specifications-ITS-XML repository on GitHub for details. >> >>One could argue ADL is easier to read and write by humans than json, yaml, >>Odin or XML. The other formats have a lot more tools available. Good thing we >>have both. >> >>Regards, >> >>Pieter Bos >> >> >> >>Op 15 feb. 2019 20:41 schreef Thomas Beale <[email protected]>: >> >>JSON, YAML and ODIN are all just object-dump serial formats that result from >>traversing an in-memory object graph, so it is a generic operation to >>generate them from tools (XML is more problematic due to being irregular in >>many ways and being schema-dependent). >> >>In the case of archetypes, the dump is just of objects that are instances of >>the >>AOM<https://specifications.openehr.org/releases/AM/latest/AOM2.html#_the_archetype_package>, >> i.e., ARCHETYPE, C_ATTRIBUTE, various kinds of C_OBJECT and so on. >> >>The ADL Workbench has an export mode (for I think around 5 yeras) that >>generates the first 3 for any archetype, and also a whole archetype library. >>The folks doing CIMI use at least the JSON mode. It also generates XML, via >>custom serialiser. >> >>One of the jobs I never completed is a deserialiser for the 3 regular >>formats, but it is nearly trivial. I am not sure if Archie or Marand's >>ADL-designer tools do the same but I think it should be trivial for them to >>implement as well. >> >>I will look into this again... >> >>- thomas >> >>On 15/02/2019 18:51, Bert Verhees wrote: >>I always admired OpenEhr for its ability to notate archetype-definitions and >>now also BMM definitions in any type. >> >>I saw experiments in XML, but the official endorsed notation language is ADL. >> >> >>I wonder, would it also be possible to write archetypes and reference-models >>in JSON? >> >>If so, it would save us tons of code, no grammars needed, no parsers needed. >>Many programming languages support JSON out of the box, with only some >>annotations needed. NoSQL Databases often support JSON, and have their own >>JSON-path based hierarchical query-languages. >> >>Venkat Subramaniam, who is a java-guru, said: "Don't walk away from >>complexity, RUN!!!" >> >>But Einstein said: "Everything Should Be Made as Simple as Possible, But Not >>Simpler" >> >>So the question is: Are there any technical objections to express archetypes >>and reference-models in JSON? >> >>Best regards >> >>Bert Verhees >> >> >>_______________________________________________ >>openEHR-technical mailing list >>[email protected]<mailto:[email protected]> >>http://lists.openehr.org/mailman/listinfo/openehr-technical_lists.openehr.org >> >>-- >>Thomas Beale >>Principal, Ars Semantica<http://www.arssemantica.com> >>Consultant, ABD Project, Intermountain >>Healthcare<https://intermountainhealthcare.org/> >>Management Board, Specifications Program Lead, openEHR >>Foundation<http://www.openehr.org> >>Chartered IT Professional Fellow, BCS, British Computer >>Society<http://www.bcs.org/category/6044> >>Health IT blog<http://wolandscat.net/> | Culture >>blog<http://wolandsothercat.net/> | The Objective >>Stance<https://theobjectivestance.net/> >> >>_______________________________________________ >>openEHR-technical mailing list >>[email protected] >>http://lists.openehr.org/mailman/listinfo/openehr-technical_lists.openehr.org
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