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Posts Tagged ‘MGrammar’

It has been more quiet around “Oslo” the last month. Maybe just about everybody is on vacations. Or people feel that everything will change with the PDC in November and are afraid of publishing nonsense.

Nonetheless, I felt it’s time for an update on what I think, heard and read about “Oslo”.

I divided my post in two sections:

  • Information about “Oslo”
  • What I think about “Oslo” today

have fun!

Some Information about “Oslo”

For those who don’t know, “Oslo” is the current codename for Microsoft’s forthcoming modeling platform, which is available as CTP Download since back in October 2008.

If you want to read more about what Oslo is about, I recommend those Resources:

Well, since then Microsoft has released two more CTP releases (January and May), written a lot of documentation and posted quite some videos and samples. If you ask me, it’s yet too much for such a young and undone technology. Oslo’s modeling language “M” has and The "Oslo" Modeling Language Specification, which yet has been implemented in JavaScript by Mathew Wilson (jsmeta).

The community did also care a lot, and there are even companies investing in tools around “Oslo”. Telrik published two projects on their Labs Site. A tool for comparing and migrating M as well as LINQ to M. There are even trainings offered by Agilitrain and PluralSight.

Some recommended links:

What I think about Oslo today
(May CTP + Announcements)

First of all I want to say, that I’m happy Microsoft released Oslo in such an early state. I think they know the pros and cons of such an open process. The community can help with forming the product, and companies can start to invest early in what they think might be valuable for the future. But It also means more friction for any changes that are made.

I have used M for defining schemas and languages and also played around with the Repository and Quadrant. As Microsoft also states, it’s early Alpha. I stumbled over many bugs which I still plan to report and blog about. But that is OK, no one ever said it was production ready.

“M”

So far I like the schema part of M, also called MSchema. It has a very concise (compared to XSD) c-style syntax and covers a lot of what I want to express when modeling information structures. The M-graph (for values) syntax is also OK, while I don’t like the MGraph API. M-constraints let you restrict your types in a nice way. What I don’t like here, is the missing support for weak constraints. Named M-queries (similar to LINQ syntax), are a nice way to query M structures.

M-grammar is useful for DSLs. I think it could be more opinionated. I feel MS is striving for an expressiveness that let you describe all computer languages in the world using MGrammar. This makes it more complex than necessary for covering DSLs. At the same time it doesn’t support nesting of languages, which would be especially useful for DSLs, because you often need to talk to external models (e.g. pinvoke). The support for editor customizing (crucial language workbench feature) as it is today is not sufficient and too hard to configure.

Another feature I miss here is referencing between nodes and even across files (linking + scoping). For now all references are just values (ids), and the output of a DSL program will be a tree model, no graphs!

The Repository

The Repository basically offers some features on-top of SQL server as are row-level security, hierarchies, localization, versioning, additional constraints. All those features are plain SQL “libraries” in conjunction with M-models which also are compiled down to SQL. I don’t yet know what to think about the Repository.

Naming / Packaging

In the last couple of weeks the Oslo team published two posts that confirmed some of my speculations.

Let’s start with Doug’s Post: On “Oslo” at Douglas Purdy

In this post he basically makes two statements:

The only thing that I feel bad about is that we kept the “Oslo” name around so long (you will see that change at the next PDC), which has continued to be a confusing point for customers (“I thought Oslo was your new SOA platform”).

Douglas Purdy

I agree. It was confusing. Although people slowly start to accept “Oslo” as for “Modeling”.

Oslo and EF / Data Programmability

With this in mind, we made a decision to merge the Data Programmability team (EDM, EF, Astoria, XML, ADO.NET, and tools/designers) and the “Oslo” team (“Quadrant”, Repository, “M”) together.

Douglas Purdy

I don’t yet know what to think about this. “Oslo” is not and should not evolve to an O/R-Mapper. M’s type system is structural and doesn’t map well to strongly typed objects as used by EF. I can see this choice limiting the modeling capabilities of Oslo. But I guess we have to wait and see.

Quadrant. A graphical Editor?

The other post, confirming my fears about Quadrant was Model Citizen : What’s So Compelling about "Quadrant" Anyway?.

Back in November last year, when I wrote a sum-up post about “Oslo” I concluded Quadrant:

Yes. Quadrant lets you interact with models graphically. It’s highly generic, customizable and it looks great.

Lars Corneliussen, November 2008, What "Oslo" is and is not

I concluded this from the official statement about Oslo plus some videos and screenshots I had seen.

A tool that helps people define and interact with models in a rich and visual manner

Doulas Purdy, September 2008, What is Oslo?

But here is the smackdown:

Microsoft code name "Quadrant" is a ‘tool for viewing and editing SQL data,’ but… so what?

Michael Murray, July 2009, What’s So Compelling about "Quadrant" Anyway?

As I understand today, and as it shows up in the May CTP, it is not a graphical editor or graphical editing toolkit but rather a light WPF-version of Microsoft Office Access that understands Oslo Modeling concepts and relationships and builds up default editors in a generic manner. This is still useful (if it is free), but not far as useful as what I hoped Quadrant to be.

Please, Microsoft, make Quadrant a graphical editing toolkit with good support for configurable diagramming and any custom WPF editors. It should also have the plug-in model VS2010 offers for sharing any extensions.

The “Oslo” Story

Microsoft tries to sell “Oslo” as if it was all one story. It’s a lie.

There is tons of impedance mismatches that restrict you in many ways.

Modeling Structure

  • M in general uses structural typing (duck typing, supports mix-ins) and supports real graphs (including references)
  • MGrammar ASTs are hierarchal (tree structure) and for now only supporting nodes and strings.
  • Databases store flat relational data,
  • and objects in the .NET world are typed nominally (no multiple inheritance).

DSLs + Repository

There is no story for “DSLs and the repository”, and there is not yet a good story for any runtime support off the repository or DSL files. It’s basically what you had before. You can either access the database via ADO.NET or an O/R-Mapper or you run directly off the parsed MGraph-AST representing your DSL-Script, which feels like visiting xml documents. M has a nice LINQ-ish query language, but that doesn’t work in memory against a graph.

Querying

M has good support for complex data structures. As said there is no support for in-memory queries. But even the database implementation is limited by it’s relational backend. Even though queries can consult complex properties for sorting or filtering, it can only return rows with a list of scalar fields.

Constraints

Most constraints on types are only implemented in the SQL-Mapping. Also here there is no in-memory implementation that would validate your model against a schema. Basically the M-compiler generates a database schema including checks that would not let you insert invalid data into the database.

Data and schema evolution

There is this dream about capturing requirements in quite fuzzy ways and then piece for piece add details to them – until they have reached some formal state that might be executable. This sounds nice in theory, but there is no chance to implement this stuff. M is very easy to change, and it is easy to add constraints and refactor schema structures. But there is no story around how to let your data evolve together with your schemas using the Repository. So, besides nice theories, Oslo doesn’t help here.

More to come

There will be new content and Chris Sells also announced a fresh CTP around this years PDC in November.

So far, only one session has been scheduled, but watch this list for more sessions to come: Microsoft PDC09 – Modeling Sessions

Hope to see you in LA in November!

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Soeben ist der dritte Artikel der DSL-Serie von Markus und mir bei der dotnetpro erschienen.

Bild 11

Abstract: Mehrspaltige Layouts für Webseiten sind komplex und stellen hohe Ansprüche an den Webprogrammierer. Warum nicht eine Sprache entwickeln, die solche Layouts vereinfacht? Mit Oslo M und dem ASP.NET MVC Framework lässt sich so eine Sprache realisieren.

Inhalt

Hauptsächlich dreht sich der Artikel um MGrammar, den Teil der Sprache Microsoft M (Teil von Microsoft Oslo) mit dem andere Sprachen definiert werden können. Zuerst wird die MGrammar (Arbeitstitel) anhand einer simplen “Hello, World”-Sprache erklärt.

Danach erstellen wir eine DSL zur Beschreibung mehrspaltiger Layouts und bringen diese mittels ASP.NET MVC und YAML ans laufen.

Das Beispiel im Artikel basiert auf der Oslo January CTP, der Quelltext für das Oslo May CTP kann aber bei mir angefragt werden.

Beispiel

Typisches dreispaltiges Portal-Layout.

Konkretes Layout - dreispalter

* Die Berechnung der Restbreite stimmt hier nicht. Richtig wäre:

Rest = (75%* Gesamtbreite) –400px

Dies mag aber von CSS-Framework zu CSS-Framework variieren.

DSL zur Beschreibung

Die Syntaxhervorhebung ergibt sich aus der Grammatik und ein wenig Konfiguration.

intellipad - Syntaxhervorhebung

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The "Oslo” team has released the third CTP of Microsoft’s forthcoming modeling platform.

Some of the  changes are:

For more detailed information check out the team announcement and the release notes.

New Installer

oslo setup

Empty Quadrant Workspace

empty quadrant

Intellipad Splitting

intellipad-multisplit And yes, I’ll be blogging about my web-layout DSL :-)

kick it on DotNetKicks.com

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Scott Hanselman about Oslo

Doug and Chris will talk about Developing RESTful Services and Clients with "M" at MIX . Scott had a chance to see a preview and posted about it:

Mix: Getting my head around Oslo, M and MGrammar

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I drafted Fowlers state-machine example with MGrammar. While doing so I found a few things I would like to see optimized or find better solutions for.

  • New line handling. I would like to express one required new line, when it is required, but then ignore all the others. Forum discussion.
    I could make new lines part of some tokens and then just interleave other tokens. But I don’t think this would be a nice solution. Any ideas?
  • The blocks events, resetEvents, commands and state+ have to be written in order. It is possible to describe a grammar where unordered blocks would be allowed, but it’s not trivial.
    Ordered and unordered “Lists” of syntaxes, separated somehow should IMHO be supported directly: forum discussion.
  • I wrote the Grammar using Intellipad and the three-pane input/grammar/AST view. It’s great! But I’d like to define the Semantic Model (using MSchema) along with the grammar and directly validate my AST against it: forum discussion.
  • References are not directly supported by MGrammar/MSchema. Forum discussion.
  • Xtext, which is quite comparable to MGrammar has a much more compact syntax. But I haven’t done a more deep comparison yet.
    Sven Efftinge’s Blog: Fowler’s DSL example with Xtext

Still missing:

  • A schema that represents the structure of the AST and validates it using constraints.
  • An adapter to Simple State Machine on CodePlex or a generating a state machine framework using T4.

Would love your feedback…

Grammar definition

module MGrammar.Net.Sample {

  // This is my first try, to parse the state machine
  // dsl syntax proposed by Martin Fowler
  language Statemachine 
  {
    interleave Ignore = " ";
    
    syntax Main = 
        NewLines? e:Block(Events, NameAndCode)
        NewLines+ r:Block(ResetEvents, Name)
        NewLines+ c:Block(Commands, NameAndCode)
        NewLines+ s:List(StateBlock)
        NewLines?
        => Statemachine 
        {
          Events { valuesof(e) },
          ResetEvents { valuesof(r) },
          Commands { valuesof(c) },
          valuesof(s)
        };
        
    // list of syntax "Item" separated by one or more
    // new lines
    syntax List(Item) = n:Item => {n}
        | list:List(Item) NewLines+ n:Item 
            => {valuesof(list), n};
    
    // lists of tokens separated by whitespaces 
    syntax TokenList(Item) = n:Item => {n}
        | list:List(Item) n:Item 
            => {valuesof(list), n};

    // a block consisting of a keyword, new-line-
    // separated "Item"s and end
    syntax Block(Keyword, Item) = Keyword 
            NewLines items:List(Item) 
            NewLines End => {valuesof(items)};
            
    // a word projected as a name
    // grouped into a separate successor
    // for extensibility reasons
    syntax Name = n:Word
        => { Name {n} };
        
    // a word plus a code, separated by spaces
    syntax NameAndCode = n:Word c:Word
        => {Name {n}, Code{c}};
    
    
    // special block and subsyntaxes for states
    syntax StateBlock = State n:Word 
            actions:(NewLines a:Actions => a)?
            NewLines+ items:List(Transition) 
            NewLines+ End 
            => State 
            {
                Name { n }, 
                actions, 
                Transitions { valuesof(items) } 
            };

    syntax Transition = e:Word "=>" s:Word
        => { Event {e}, ToState{s} };
        
    syntax Actions = tActions "{" l:TokenList(Word) "}" 
        => Actions [ valuesof(l) ];
    
    
    // keyword specification for strong formatting
    @{Classification["Keyword"]} final token Events = "events";
    @{Classification["Keyword"]} final token Commands = "commands";
    @{Classification["Keyword"]} final token ResetEvents = "resetEvents";
    @{Classification["Keyword"]} final token State = "state";
    @{Classification["Keyword"]} final token End = "end";
    @{Classification["Keyword"]} final token tActions = "actions";
    
    
    // Some whitespace characters
    token NewLineCharacter 
            = 'u000A'  // New Line
            | 'u000D'  // Carriage Return
            | 'u0085'  // Next Line
            | 'u2028'  // Line Separator
            | 'u2029'; // Paragraph Separator
            
    token NewLines = NewLineCharacter#2..;
         
    token Letter = 'a'..'z' | 'A'..'Z';
    token Digit = '0'..'9';
    token Word = (Letter (Letter | Digit)*);
  }
}

Input Text

events
  doorClosed  D1CL
  drawOpened  D2OP
  lightOn     L1ON
  doorOpened  D1OP
  panelClosed PNCL
end

resetEvents
  doorOpened
end

commands
  unlockPanel PNUL
  lockPanel   PNLK
  lockDoor    D1LK
  unlockDoor  D1UL 
end

state idle
  actions {unlockDoor lockPanel}
  doorClosed => active
end

state active
  drawOpened => waitingForLight
  lightOn    => waitingForDraw
end

state waitingForLight
  lightOn => unlockedPanel
end

state waitingForDraw
  drawOpened => unlockedPanel
end

state unlockedPanel
  actions {unlockPanel lockDoor}
  panelClosed => idle
end

Output AST

Statemachine{
  Events{
    {
      Name{"doorClosed"},
      Code{"D1CL"}
    },
    {
      Name{"drawOpened"},
      Code{"D2OP"}
    },
    {
      Name{"lightOn"},
      Code{"L1ON"}
    },
    {
      Name{"doorOpened"},
      Code{"D1OP"}
    },
    {
      Name{"panelClosed"},
      Code{"PNCL"}
    }
  },
  ResetEvents{
    {
      Name{"doorOpened"}
    }
  },
  Commands{
    {
      Name{"unlockPanel"},
      Code{"PNUL"}
    },
    {
      Name{"lockPanel"},
      Code{"PNLK"}
    },
    {
      Name{"lockDoor"},
      Code{"D1LK"}
    },
    {
      Name{"unlockDoor"},
      Code{"D1UL"}
    }
  },
  State{
    Name{"idle"},
    Actions[
      "unlockDoor",
      "lockPanel"
    ],
    Transitions{
      {
        Event{"doorClosed"},
        ToState{"active"}
      }
    }
  },
  State{
    Name{"active"},
    Transitions{
      {
        Event{"drawOpened"},
        ToState{"waitingForLight"}
      },
      {
        Event{"lightOn"},
        ToState{"waitingForDraw"}
      }
    }
  },
  State{
    Name{"waitingForLight"},
    Transitions{
      {
        Event{"lightOn"},
        ToState{"unlockedPanel"}
      }
    }
  },
  State{
    Name{"waitingForDraw"},
    Transitions{
      {
        Event{"drawOpened"},
        ToState{"unlockedPanel"}
      }
    }
  },
  State{
    Name{"unlockedPanel"},
    Actions[
      "unlockPanel",
      "lockDoor"
    ],
    Transitions{
      {
        Event{"panelClosed"},
        ToState{"idle"}
      }
    }
  }
}

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See also: Open Letter to Douglas Purdy: Eclipse, Oslo, and how to invent the future together

The PDC is over, and most contents including the Oslo SDK (without Quadrant) and all PDC Session Videos on channel9. Thanks! But where are we now? If you want a “brief” overview, you should at least have a look at A Lap around “Oslo”.

Jump to “What Oslo definitely is!”

Oslo Resources

What Oslo is not!

I’ll start with correcting some of my former assumptions in DSL Tools, T4, the Software Factories and “Facts” Rumors about Oslo.

Built upon DSL Tools?

No, Oslo (M and Quadrant) is not built upon DSL Tools, T4 and the UML Tooling in Visual Studio 2010. It’s totally apart. The DSL Tools are the here and now, while Oslo still is “Pre-Pre-Pre-Alpha” (Douglas Purdy).

Douglas promised that his team is working tight with the VSTX team in order to bring this together. He mentioned the possibility of using M as the backing metamodel format for the DSL Toolkit. Graphically edited DSLs could then be converted, described in MSchema and stored into the Oslo Repository or MGraph files. Update (12.Nov): Later in his talk “a lap around Oslo” Doug also said his the team is discussing to schematize the DSL Toolkit, and let the graphical DSLs live within Oslo.

A move towards UML/OMG?

No. I don’t think so. Microsoft joined the OMG and they support some UML Diagrams in Visual Studio 2010. But so far this has not to do much with Oslo.

Update (12.Nov): Someone asked about how Oslo relates to XMI and UML. Doug’ promised that they will model the UML-Domain and let the UML Designers in Visual Studio live within Oslo.

Talking of Model-driven Architecture (MDA) it seems that Microsoft avoids this abbreviation. They rather talk about Model-driven Development and Model-driven Applications – I’ll write more on this in a separate post.

A Application/Process Server?

Dublin is announced to be Model-driven, but it is not a part of “Oslo”, but rather related to Windows Azure and IIS. The plan is to host cloud-enabled services both locally on Dublin and in the cloud on Windows Azure with maximal control and minimal effort for deployment and configuration.

Read Workflows, Services, and Models by David Chappell to see how Dublin relates to Oslo.

A new Version of WF and WCF?

WCF and WF were model-driven right from the beginning, but in the next versions the source for the models that drive Workflows and Services might come from Oslo.

MService is a textual DSL that combines service configuration, implementation and workflow definition into one resource.

What Oslo definitely is

A new Modeling Language Family

Yes, it’s definitely about a new modeling language family “M”, consisting of three core languages. These languages do all have similar Syntax and a shared type system.

  • MSchema
    Defines schemas for data instances. Quite comparable to XSD and DTD.
  • MGraph
    JSON-like format for capturing concrete data instances.
  • MGrammar
    Defines grammars for textual DSLs. Could also be looked at as a Unicode-to-MGraph-tranformation language.

There are other languages planned for some horizontal domains as Database, Services and Web. But here you can even put some more “Pre”s before the “Alpha”.

A Language Workbench for textual DSLs!

Well, I’ll just copy Martin on that.

At some point I really need to rethink what I consider the defining elements of a Language Workbench to be. For the moment let’s just say that Xtext and Oslo feel like Language Workbenches and until I revisit the definition I’ll treat them as such.

Martin Fowler Bliki: Oslo

A new Storage Repository!?

Oslo Repository is a tool and a framework that allows storing models into SQL Server.  I’m still quite torn on this idea.

  • Design-time story: Many tool vendors tried backing repositories supporting simultaneous changes. But sharing them in files is just easier. If it was on the web – ok, then we had to talk about security and stuff – But as it is tied to SQL Server 2008, it looses a lot of my attention.
  • Runtime story: Having models in a database at runtime at least seams more natural in my opinion. What then to store there is another thing to figure out. Is it meant to store operational data or configurations and application definitions? That’s what is left to the customer to decide.

The repository compiler (mx.exe) generates T-SQL code out of your models, while it supports two modes:

  • Plain T-SQL: Mapps your explicit MSchema definitions or implicitely “guessed” schemas from MGraph data to data tables.
  • Repository SQL: A Repository is a database pre-populated with tons of schemas describing the “Microsoft IT world”. It also supports some core services, as are:
    • Deployment: Import and Export from and to M + Webservice Deployment to Dublin
    • Security: Tables hidden behind views, claims-based security
    • Catalog: Keeps the semantics you have in your MSchema as not everything maps directly to T-SQL.
    • Versioning: Sadly not instance data versioning. But you got full SQL Server 2008 capabilities including SSIS, Change Tracking, Replication, … + Due to the separation of views and tables you can support backward-compatible schema evolution.

Oslo does not come with a own data-access technology stack. It rather gives you a generator for EF-Models.

A Graphical Modeling Toolkit!

Yes. Quadrant lets you interact with models graphically. It’s highly generic, customizable and it looks great.

But as I’ve understand, Quadrant only works on models stored in the Repository, hence SQL Server. Really interested to see how this works together with your textual definitions you might rather store in Version Control.

Release Dates, Packaging and Pricing

From Microsoft “Oslo” Frequently Asked Questions

Q: What is the timeline for shipping “Oslo”?

A:  We are not disclosing the release schedule at this time. We are committed to releasing regular Community Technology Previews (CTPs) after PDC and will engage with the developer community on an on-going basis. The Oslo Development Center (http://msdn.microsoft.com/oslo) will also be the place to learn about the latest Oslo-related downloads.

Q: Is “Oslo” shipping with the rest of the Visual Studio 2010 product line?

A: We are not currently disclosing schedules or packaging.

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Oslo CTP available!

The Oslo SDK is available for download: Oslo Developer Center

Microsoft also did a good job writing a lot of examples, documentation and tutorials about Oslo, M and MGrammar and the Oslo Repository.

M vs. MGrammar

MGrammar looks quite interesting. As I can see, M is defined using MGrammar while MGrammar itself is self-describing.

M just seems to be a general-purpose modeling DSL. This is where “building textual DSLs” comes in. When you want to define a model you can either define it with M, or create an own more specific DSL using MGrammar. MGrammar will then generate a parser and hopefully a good intellisense-enabled editor.

Screenshots

I’m really to tired to run all of the samples and tutorials and come up with good conclusions. But I got some screenshots :-)

That’s what “M” looks like. Unfortunately I could not find any examples or screenshots about Quadrant, which should show the same data just graphically.

tmp201

 

More than 300 built-in models.

tmp1FF

 

The Intellipad helps writing Models with M or defining textual DSLs with MGrammar.

tmp20D

 

A part of MGrammar defined in MGrammar

tmp213

 

A part of M defined in MGrammar

tmp215

 

A textual DSL built with MGrammar

tmp217

 

An instance of this DSL

tmp219

 

More tomorrow!

It’s 01:42 am here in Germany, and I just want to sleep now :-)

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