1 From Eviss to Viola: Visual Parser Generators based on Extended Constraint Multiset Grammars Jiro Tanaka University of Tsukuba

2 Contents Visual Parsing Visual Parser Generators  Eviss  Viola

3 Visual systems and visual languages Visual systems are systems that process visual languages. Visual languages are two (or more) dimensional languages with have structures. ER-diagrams customergoodsorder No.name numberNo.nameprice Class diagrams text left width height cut select Box select deselect Link name add sheet next sheet save load Drawing Collection cut copy move Selection delete Sheet

4 Visual parsing: motivation ⇒ We would like to implement visual systems with less effort and time.

5 What is Necessary 2D version of yacc (text -> visual)  A visual parser generator such as yacc which generates a parser if rules and actions are given. Easy visual system builder  Make visual systems with less efforts, only by giving their rules.

6 What i s Necessary (2) Generated visual systems keep the semantic relationships between figure elements, when moved

7 Visual Parser Generator: Grammar  Extended CMG (Constraint Multiset Grammars)

8 Extended CMG Extended Constraint Multiset Grammar CMG is used to describe the relationship between figures using constraints. Extended CMG is obtained by adding various actions to CMG. val

9 Actions Actions are arbitrary script such as  calculating values  creating widgets  redrawing the figures in the execution window alter the attributes of the figures move the figures create new figures delete the figures

10 3 * How the ListTree is Parsed 1. ListTree consists of a circle with a text string in it. No arrow comes into the node. 2. ListTree consists of a circle with a text string in it. There exist two arrows which come into the circle. Each arrow comes from another ListTree. 3 * 4 5 +

11 Contents Visual Parsing Visual Parser Generators  Eviss  Viola

12 Visual Parser Generators We have implemented a series of visual parser generators based on Extended CMG. Eviss [1997] is the first one.  Implemented in Tcl/Tk Viola [2004] is the latest one.  Implemented in Java

13 “Eviss” System Definition window Grammars are defined here. Execution window Generated systems can be used here. Relationships between figure elements are preserved.

14 Defining Rules Rough Rules can be defined visually. Eviss translates them into textual form. The user modifies - attributes - actions - constraints

15 Applications VSH calc treestackSTD VSH GUI BuilderHIVISUALVISPATCH 5 * 34 +

16 Calculation Tree * 34 + Calculation Tree

17 Stack a b c a b c

18 State Transition Diagram Editor

19 VSH (Visual Shell)

20 GUI Builder

21 HIVISUAL [I. Yoshimoto, 1986]

22 VISPATCH [Harada,1997]

23 More Application Recursive Drawing of a Comic Character

24 Problems with Eviss Needed to define Extended CMG rules textually. Difficult to the end users.

25 Features of Viola The user can define the rules by direct manipulation, without describing rules in text. Implemented in Java (J2SE v1.4.1) As a constraint solver, Chorus [Hosobe 2001] is used.

26 Features of Viola (2) No distinction between the definition window and the execution window. We can define the rules and execute the visual system dynamically.

27 Demo: Network Structure Diagram

28 Summary Visual Parser Generators based on Extended CMG are described. They generate the spatial parsers, if the rules for the visual languages are given.  The grammars are based on the extended CMG. In Viola, the user can define rules and execute them dynamically.

29 Future direction: Meta-GUI Write meta-interpreter of Viola in Viola cf. Vispatch

30 Free Software Packages EVISS is available from More Info:

31 From Eviss to Viola: Visual Parser Generators based on Extended Constraint Multiset Grammars Jiro Tanaka University of Tsukuba