Re: [gmt-dev] Re: example meta model etc.

["Jorn Bettin" <jorn.bettin@xxxxxxxxxxxxxxxx>]

> > The MDA concepts of PIM and PSM are not very helpful for meta
> > modelling (the
> > domain of "designing a domain-specific language) - it makes no
> > sense to talk
> > about a PIM and a PSM of a meta model. What you *do* have is an abstract
> > syntax of your DSL and a concrete syntax of your DSL. In the meta
> > model you
> > define the abstract syntax. With our current technologies the mapping to
> > concrete syntax occurs in the templates you use to generate the
> > specification tool.
> I do not agree with this. As an application developer it makes no
difference
> to me whether I am building an application to visualize "AddressBooks" or
> "BusinessComponents".

We need no further mapping. Everything we need for the implementation is
derivable from the meta model. All we need is a thinn handcrafted reference
implementation from which we can derive templates.

> > For a visual DSL with boxes and lines you'd need to capture the
geometric
> > coordinates in the concrete sytax aspect, and assign appropriate shapes
to
> > the various elements. But as agreed, all that's not part of step
> > 1 for GMT,
> > so we don't need a concrete syntax aspect just yet.
> I think the discussion would be much clearer if we would stop talking
about
> generating visual DSL's or specification tools for the time being.

For step one were not talking about visual DSLs, see above. Replace
"specification tool" with "Specification Application" if you want.

> Let's
> talk about creating a tool that allows specification of business
components
> (where your example model is the meta model and not UML). And yes, it
needs
> a GUI, and yes, we need to apply MDSD. If we have successfully done that,
we
> can talk about how to automate the process of tool development for other
> DSL's. You cannot build a shoe factory if you do not know what shoes look
> like.

That's what the reference implementation is for... MDSD starts with a
reference implementation...

>
> I am trying to imagine approaching the very smart group of Irish
developers
> I was working with last year, and telling them: Define a small number of
> GATEWAY META CLASSES, IGNORE THE CONCRETE SYNTAX in your transformation
> engine, and by the way, no visualization. ...
> Instead of: lets define a mapping from our business model to the GUI and
> another mapping from our business model to the database, and by the way,
> here is a graphical tool that supports defining the mapping.

We don't need to manually map the tool model (the "business model") to a UI
model, a DB model etc if all these mappings are automatically derivable by
applying a set of transformations to the model. These transformations in
turn are specified in templates derived from the reference application.

Jorn

Jorn Bettin
jorn.bettin@xxxxxxxxxxxxxxxx
www.softmetaware.com
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