tag:blogger.com,1999:blog-62789619962960341362011-07-07T17:05:34.861-07:00Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.comBlogger401100tag:blogger.com,1999:blog-6278961996296034136.post-87898795809134890932009-07-24T15:40:00.000-07:002009-07-24T16:19:33.450-07:00

JetBrains just released version 1.0 of its Meta Programming System. The screencasts provided by Markus Völter are very nice. They show how the Java base language can be extended by a lock abstraction, which is translated to some best practice lock code by the generator component afterwards. This seems to be a good example of growing a language as motivated by Guy L. Steele Jr. I wonder whether

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-29977730892262258252009-07-18T08:19:00.000-07:002009-07-18T08:45:52.388-07:00

Now I have also constructed an editor for alligator eggs. This editor is different from Torsten's editor with the nice animation discussed some days ago. My editor provides syntax-based user assistance instead, i.e. the user gets help in creating syntactically correct alligator eggs expressions. Whereas Torsten's editor has been created with DiaMeta (syntax defined by a class diagram), my

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-55402560555783963202009-07-15T12:10:00.000-07:002009-07-15T12:44:16.093-07:00

The video about the animated editor for Alligator Eggs has raised some questions on where the editor is available for download. Therefore, Torsten has provided an executable jar. Feel free to try it out yourself!Actually, the success of this video on youtube (more than 3.000 views already) really motivates me to implement syntax-based assistance for the language of alligator eggs. The language is

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-61996106245520554332009-07-15T11:38:00.000-07:002009-07-15T12:06:09.676-07:00

In the last weeks I have developed an editor for business process models with syntax-based user assistance as described in previous blog posts. A screencast of this editor is shown below:The editor is provided for download as an executable jar.Concepts and realization are described in S. Mazanek, M. Minas. Business Process Models as a Showcase for Syntax-based Assistance in Diagram Editors.

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com1tag:blogger.com,1999:blog-6278961996296034136.post-67673512075390359942009-07-08T07:07:00.000-07:002009-07-08T07:16:41.591-07:00

At the moment I spend a lot of time on polishing my PhD thesis. Therefore, not so many new posts appear on this blog in these days. However, today I would like to follow up on my last post, which was about the visual language of alligator eggs. A colleague of mine, Torsten Strobl, has created a very nice editor for alligator eggs expressions. It even animates the evaluation of such expressions,

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com9tag:blogger.com,1999:blog-6278961996296034136.post-32580724469309734342008-12-10T04:39:00.001-08:002008-12-10T04:58:44.822-08:00

Some time ago I had already written about a nice visualization of lambda calculus called VEX (visual expressions). In VEX the variable bindings are made explicit by using connecting lines. In contrast, in conventional lambda calculus bindings are implicitly given by the names of the variables. From my experience this is difficult to understand for students, in particular if alpha conversion comes

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-76094595515547198002008-11-18T03:33:00.000-08:002008-11-18T06:37:04.054-08:00

Directly after the World Usability Day in Dresden I attended the Graph Transformation Day in Bremen. Here, I gave a talk about the generation of correctness-preserving editing operations for diagram editors. More on this later...The other talks have been given by my supervisor Prof. Mark Minas (about using triple graph grammars for analysis in diagram editors), Dr. Rubino Geiß, the architect of

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-51648774878370677852008-11-18T00:51:00.001-08:002008-11-18T01:23:56.435-08:00

Last Thursday I gave a talk at the World Usability Day Dresden with the title "Nutzerunterstützung in Diagramm-Editoren zum Erlernen visueller Sprachen" (in English: User assistance for diagram editors supports the learning of visual languages). I provide an abstract of my talk (in German) on my website. I got quite encouraging feedback and some nice tips on how to actually conduct a user

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com1tag:blogger.com,1999:blog-6278961996296034136.post-31741113760973119442008-09-25T10:30:00.000-07:002008-09-25T10:56:48.634-07:00

In recent posts I have already demonstrated the power of diagram completion.In the paper I have presented at this year's LED workshop, I have shown how diagram completion can be used in order to facilitate a completely novel(?) approach to diagram editing. It is enough to just roughly sketch your diagram. You do not need to hit the mark quite precisely anymore as required in traditional diagram

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-79584378304493384142008-09-16T07:56:00.000-07:002008-09-16T08:25:08.686-07:00

The Visual Week in Herrsching, Germany is already up and running. Yesterday the Workshops Layout of (Software) Engineering Diagrams and Sketch tools for diagramming took place. I attended LED where I gave a talk with the title "Exploiting the Layout Engine to Assess Diagram Completions" (paper and slides). But I also really enjoyed the other talks that covered a wide range of topics from industry

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-11656639285900256122008-07-19T07:24:00.000-07:002008-07-20T03:58:57.528-07:00

In this post I briefly discuss usability. First of all, I have to say that there is so much research that it is nearly impossible to write a short blog post about this topic. For instance, Jakob Nielsen, a popular usability expert, writes about usability for years. So I will just give you a quick impression by introducing the GOMS approach, which I found very straightforward and easy to apply. I

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-24551351337687243542008-07-18T03:50:00.000-07:002008-07-18T04:27:54.751-07:00

I am just back from the RTA 2008 (Rewriting Techniques and Applications) conference in Linz. My talk has been on Wednesday and was about Functional-logic Graph Parser Combinators. I already have written on this blog about graph parser combinators, but this purely functional approach had several problems we solved using functional-logic programming techniques. In particular, the new framework can

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-7940280972576365162008-07-14T08:35:00.000-07:002008-07-21T06:50:45.107-07:00

In previous posts I already have discussed several visual languages like VEX, Trees or ER diagrams. These languages have in common that all of them are used by computer scientists. Of course, visual languages also exist in other domains (in fact, visual notations are much older than computers). In this post I show an editor for a language mainly used by electrical engineers: Logic gates. This is

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-41938994164502183472008-07-12T01:03:00.000-07:002008-07-12T01:56:14.757-07:00

I already have written several posts about our previous course on graph and model transformation conducted in autumn last year and the practical afterwards. Next autumn we will hold another course, this time directly on visual languages. We will discuss approaches to language definition like extended positional grammars, constraint multiset grammars, hyperedge replacement grammars, and, of course

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-84574765870289018582008-07-07T23:46:00.000-07:002008-07-08T04:29:30.979-07:00

Trees are a central data structure in computer science. A lot of visual languages have a tree-like structure, for instance class hierarchies with single inheritance, family trees or organizational charts. In contrast to the language of all graphs the sublanguage of trees can be described in a context-free way with a hyperedge replacement grammar:However, this straightforward definition is

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-65994472439133479472008-07-05T05:18:00.000-07:002008-07-08T00:24:09.247-07:00

I got stimulating feedback after my last post on diagram completion. For instance, I was not aware of the SmartEMF project of Anders Hessellund et al. They aim at extending EMF with an inference engine to facilitate reasoning about models. Interestingly, they also get some guidance that way. A similar approach has been realized in the AToM3 tool by Sagar Sen et al. They also employ constraint

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-81347373274661920072008-07-01T07:30:00.000-07:002008-07-08T00:23:24.972-07:00

Recently I have been working on an approach to diagram completion. This kind of assistance helps users in correcting and extending diagrams. That way they can learn new languages much more easily. Furthermore, the construction of complex diagrams is also greatly simplified.Following my approach, completions are computed on the abstract syntax level with respect to a hyperedge replacement grammar.

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-48954942085826692682008-04-27T22:01:00.000-07:002008-04-27T23:44:15.382-07:00

I have already introduced my approach to graph parsing via Graph Parser Combinators on this blog recently. This time I provide a nice sample parser; at RTA I will present the concepts and how the used framework can actually be realized in the functional-logic programming language Curry.The example I am going to discuss are Sierpinski triangles. This graph language is particularly interesting for

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-87230166496291108292008-04-22T02:57:00.000-07:002008-04-22T07:10:14.106-07:00

Let's continue talk about our practical on graph and model transformation. In fact, it is already finished, but unfortunately I did not managed to write about the other stages in time. Remember, that in the first stage a UML class diagram editor had to be developed by the student teams using different meta-CASE-tools. The second stage, in contrast, was focused on transformations. The students had

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-20126056967836645672008-04-03T10:05:00.000-07:002008-04-03T11:23:28.184-07:00

I am back from Budapest where I have attended the GTVMT workshop and ETAPS. The feedback to my talk about graph parser combinators was positive and I even have been pointed to very useful and interesting references later. I will provide a more detailed post about my stay in Budapest soon.Let me just point you to an up to date news from the DSL tool market. I have already written about the

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com1tag:blogger.com,1999:blog-6278961996296034136.post-45668304816576255962008-03-06T02:21:00.000-08:002008-03-06T02:30:03.547-08:00

From September 15th, 2008 on the Visual Week will take place in Germany near Munich. Our department is organizing this event headed by Prof. Dr.-Ing. Mark Minas. One of the main conferences is the VL/HCC 2008, the 2008 IEEE Symposium on Visual Languages and Human-Centric Computing. Paper submissions here are due to March 11th, i.e., next Tuesday. I hope to see you in Herrsching.

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-70564061752451011302008-02-22T08:11:00.000-08:002008-02-22T08:39:45.382-08:00

The effort of blogging already seems to pay off as I start to get mails with interesting references to related work. Yesterday Miguel Garcia pointed me to his workshop paper Bidirectional Synchronization of Multiple Views of Software Models. What I liked about the paper is its discussion of related work and the references that give a very comprehensive overview of the state of the art in this

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com1tag:blogger.com,1999:blog-6278961996296034136.post-21890095549591506922008-02-21T11:19:00.000-08:002008-02-21T12:02:18.222-08:00

The first stage of our practical on graph and model transformation is already finished. The students have produced nice class diagram editors with all three meta-CASE-tools. As expected, all tools have particular strengths and weaknesses. GMF:Strong points: open source, integration with popular eclipse platform and EMF, wizards, tutorialsWeak points: difficult to realize nested packages, internal

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com2tag:blogger.com,1999:blog-6278961996296034136.post-66837763785621641492008-02-12T06:10:00.000-08:002008-02-23T13:29:53.980-08:00

Let me today write about a tool I have tried recently: VlDesk. Compared to other research tools VlDesk outstands with a comprehensive website (including demos) and smooth installation procedure. The underlying formalism, eXtended Positional Grammars (XPG), is well-studied (see further reading) and allows for efficient parsing. In fact, the parser is generated using the well-known Yacc parser

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-50688371791983593412008-01-30T12:32:00.000-08:002008-01-30T13:12:06.011-08:00

This post is about a topic I am particularly interested in, namely Graph Parser Combinators. Among functional programmers parser combinators are very popular. They are fun to play with and a lot of research has been done to make them more practically relevant (mainly by improving efficiency). There is an abundance of different libraries, e.g., the HUT Parser Combinators, Parsec or polyparse.Since

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-52784128411234764172008-01-16T01:08:00.000-08:002008-01-16T05:26:20.235-08:00

VEX (visual expressions) is a VL for the representation of lambda expressions.The picture provides two exemplary VEX expressions. The upper one represents the lambda term λy.(x y), i.e. a function that applies the free variable x to its argument. The other one represents the term λx.λy.(x y). Here variable x also is bound by an abstraction.VEX is a very simple visual language in the sense that

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-45835660432035240822008-01-11T22:12:00.001-08:002008-01-11T22:32:22.584-08:00

I have already written several posts regarding our seminar on graph and model transformation. The next three months we conduct a practical on graph and model transformation on top of this seminar.The first task is the implementation of an editor for UML class diagrams (restricted to classes, attributes, generalizations and a limited notion of associations). However, the editor should, of course,

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com2tag:blogger.com,1999:blog-6278961996296034136.post-47720472030502513492008-01-06T21:13:00.000-08:002008-01-06T21:39:33.208-08:00

In the last days I had to deal a lot with entity relationship (ER) diagrams, because I have to conduct exercises for a database course. ER diagrams have been developed in the seventies by Chen and are a widely used visual language for the conceptual design of database systems. Further in my last post I described the tool AToM3 whose main formalism is ER.This figure is from the wikipedia article

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com5tag:blogger.com,1999:blog-6278961996296034136.post-33727359840581350912008-01-06T03:56:00.000-08:002008-01-06T21:42:19.767-08:00

I am back from vacation and continue reporting about the seminar talks. On 29.11.07 we discussed the tool AToM3, a research project of Hans Vangheluwe and Juan de Lara. AToM3 is an acronym for "A Tool for Multi-formalism and Meta-Modelling". From my point of view its main features are:meta CASE-tool: specify a visual language (formalism) and generate an environmenthomogeneous view on

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-3015748098096761582007-12-15T05:20:00.000-08:002007-12-15T03:50:13.708-08:00

So, today I continue blogging here. Kindly excuse the fairly long period without a post. The submission deadline for the conference GTVMT was so rapidly approaching...The next talk in our seminar was about DiaMeta, the successor of the diagram editor generator DiaGen. In contrast to DiaGen DiaMeta is based on a metamodel instead of a hypergraph grammar. Not that metamodels are more powerful: this

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-64280699347632406912007-11-26T05:01:00.000-08:002007-11-30T05:20:41.910-08:00

The next talk in our seminar was about ATL, the ATLAS transformation language. The talk took place on November 15, 2007, the same day we already discussed MOF QVT. The main difference between ATL and QVT is, that QVT is just a specification whereas ATL is both a language AND an implementation.We just recall the essence of model transformation. Say, we want to define a model transformation between

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com4tag:blogger.com,1999:blog-6278961996296034136.post-44432553705270758142007-11-23T12:19:00.000-08:002007-11-23T05:21:16.782-08:00

This is a short review of the book "UML2 Certification Guide - Fundamental & Intermediate Exams" by Weilkiens and Oesterreich. The purpose of the book is to prepare for the UML exams of the OMG, a way to certify different levels of knowledge about the UML.This book is NOT for learning UML. It does not focus on UML diagrams, but on the abstract syntax of UML as defined in the specification. The

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-61274493604724347582007-11-23T09:28:00.000-08:002007-11-23T05:25:41.256-08:00

MetaEdit+ is a commercial tool for both the design and use of (domain-specific) modeling languages (a meta-CASE-tool).The underlying metamodeling language in MetaEdit+ is called GOPPRR and is very simple. There are just Properties and Non-Properties (which in turn can have Properties again). Non-Property-Types are Graph, Object, Port, Role and Relationship, and for each of these types there is a

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com1tag:blogger.com,1999:blog-6278961996296034136.post-81783739291960176562007-11-17T02:19:00.000-08:002007-11-18T21:52:05.419-08:00

This post is about MOF QVT (Query/View/Transformation), a model transformation language we also discussed in the course of our seminar (November 15, 2007). First of all lets briefly explain these three terms:A query basically is an expression evaluated over a model. OCL is a prominent example of a query language that we will discuss in a future post.A model completely derived from another model

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-10610728018184152572007-11-15T04:28:00.000-08:002007-11-15T21:49:41.651-08:00

On November 8, 2007 the student presentation about the metamodeling frameworks EMF and MOF took place. Note, that on this blog there will be many more posts about EMF and MOF (in fact, theses metamodeling frameworks are an essential part of my research), so that this initial post is just to give you a start.Metalayers up to MOFSo, why do we need metamodels? In computer science we usually describe

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-78437169613898624082007-11-15T04:24:00.000-08:002008-01-16T05:26:49.598-08:00

The next student presentation in our seminar was about DiaGen, the diagram editor generator developed at our department. It was also held on October 25, 2007. The main advantages of DiaGen editors are (from my point of view):combination of free-hand editing and syntax-directed editingon-line syntax checks of diagrams during the editing process, partially correct diagrams as intermediate steps are

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-45057330014817030172007-11-15T04:09:00.000-08:002007-11-15T04:24:24.266-08:00

You may be interested in using my public google calendar for conferences about visual languages:I will assume no liability for the correctness of all dates. Its just a service. If you think an important date is missing or wrong please drop me a note.

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-74255536917434957772007-11-15T01:34:00.000-08:002007-11-15T03:28:11.497-08:00

The second talk was held on October 25, 2007. It was about Hyperedge Replacement Graph Grammars HRG. I know, I know, ... In the last post I promised to focus more on practical things. But: Hyperedge replacement is more practical than you might think. For instance, hypergraphs can be used as a model for visual languages as realized in the tool DiaGen. Following this approach a visual language can

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-88950835079591640422007-11-15T01:05:00.000-08:002007-11-15T01:33:55.103-08:00

Let's start with the first talk of the seminar held on October 18, 2007 about the algebraic approach to graph transformation that can be subdivided in the single and the double pushout approach. These terms sound quite daunting, but the underlying concept is not hard to grasp. Both approaches are based on the concepts graph, production and graph grammar, that I will not introduce here in detail.

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0tag:blogger.com,1999:blog-6278961996296034136.post-53120593088219385532007-11-15T00:11:00.000-08:002007-11-15T01:18:12.747-08:00

My name is Steffen Mazanek and I am a scientific assistant at the department of computer science of the Universität der Bundeswehr, Munich. Here I work on my PhD thesis in the field of visual languages. My supervisor is Prof. Mark Minas.I am also involved in teaching. For instance, this semester we conduct a course on graph and model transformation. I think this is a good starting point for this

Steffen Mazanekhttp://www.blogger.com/profile/09731971758303543668noreply@blogger.com0