Annotation concepts - what they are?

Could you please be more specific about where you found the TODO statement? Was it somewhere in the documentation (do you have a link) or in code?

Here in section "Annotation concepts"

Hi Vabav,
this section simply is not yet written. ;) Annotations can be put on existing concepts, properties, and links of languages without modifying the original language. Please watch this screencast for an introduction: http://tv.jetbrains.net/videocontent/extending-existing-languages-through-attributes The interesting part for annotations starts around 11:50.

jens

Thanks, Jens! :-)

Sorry for saying this but i think also that your MPS' documentation is far from perfect (I've started on MPS 3.0 documentation and in process of reading this understood that there is no hope to get thorough understanding of MPS through it — if there is info in it about what are operationContexts, for example, there are no links to such info in it). I've assumed that the official way is to get through Fast Track to MPS and am now going through it. Is it the way to get MPS right in full detail?

Hi Vabav,
you are right, MPS' documentation is not a thing like a "Language Workbench Beginners Course". There are three main parts new in this kind of programming:

• DSL Engineering
  
• Language Workbenches
  
• MPS as one product of 'Language Workbenches'

So for starting I would recommend to watch the other MPS screencasts on jetbrains.tv too and also Markus Völters Language Modularization and Composition with MPS series on YouTube, starting with https://www.youtube.com/watch?v=lNMRMZk8KBE
Play around with the samples from screencasts and the ones coming with MPS.

The problem is that documentation should be either a reference material, covering MPS in full details with cross-references, or a one-topic-at-a-time material, in which topics are covered in, well, topological sort order — i mean all dependencies between topics are aligned to be dependencies going only forward in respect to pages order, so that you don't need to jump and search for not covered to the moment topics, so your reading is linear. JetBrains' documentation is neither of these things — and that's a problem :-(

Regrettably the screencast is not up to date with MPS 3.0EAP.  In 3.0 defining annotations has become much more complex and less intuitive.  In 2.5 you just added the role and the list of attributes concepts.  In 3.0 you now have to override two methods: static string getRole() and static list<node<AbstractConceptDeclaration>> getAttributed(). I do not know the rationale behind this change, but I think this is a big step backwards. In 2.5 attributes were a first class citizen and in 3.0 they are not.

By the way, where concept properties/links are in 3.0?