classgen

4. Examples

These three examples are supposed to be an introduction to classgen. You can load a vcg-generated diagram representation and download the examples.

Expression

A typical example for an abstract syntax tree representing an expression.
download | view


package sample1;



attribute "int"      evalResult      with Expression;

attribute "boolean"  calculated      with Expression;



Expression  ::= {IntegerConstant} "int":value

              | {BinaryExpression} Expression:lhs "int":op Expression:rhs

              

Operator    ::= enum PLUS, MINUS, MULT

Compiler design

An example taken from the compiler design course at TUM.
download | view


package sample2;



attr "boolean" istvarParam, istformParam with Dekl;

attr DeklInfo deklinfo with Id_Seq, Var;



Prog ::= "String":ident  Proc_Dekl_Seq  Block





Proc_Dekl_Seq ::= Proc_Dekl Proc_Dekl_Seq

                | /* leere Sequenz */



Proc_Dekl     ::= "String":ident Form_Par_Seq Block



Form_Par_Seq ::= Form_Par Form_Par_Seq

               | /* leere Sequenz */



Form_Par     ::= { Param }     Var_Dekl

               |  { Var_Param } Var_Dekl

             

Var_Dekl     ::= { Variable }  Typ  Id_Seq:id_Seq

               |  { Array_Variable } "int":laenge Typ Id_Seq:id_Seq



Typ      ::=    "int":typ  

              

Block    ::= Dekl_Seq  Anw_Seq



Dekl_Seq ::= Dekl Dekl_Seq

           | /* leere Sequenz */



Dekl     ::= { Var_Dekl }   

           



Id_Seq   ::= "String":ident Id_Seq

           | "String":ident 

          



Anw_Seq ::= Anw Anw_Seq

          | Anw



Anw     ::= Ausdr   





Ausdr     ::= {BinAusdr}  Ausdr "int":op Ausdr

            | {IntAusdr}  "int":value

            | {VarAusdr}  Var



Var        ::= {IdentAusdr}   "String":ident

            |  {ArrayAusdr}   "String":ident Ausdr:index

Layout

This example describe classes that are commonly uses in box-glue layout algorithms.
download | view


package sample3;



/* Aus dem PP WS 99 WS 99 */



attr "int" boxWidth, boxHeight, boxDepth with Box, ItemList;

attr "int" actual with Item;

attr "boolean" inHBox with ItemList;

attr "int" requSize with ItemList;





Page		::= Box:content

Box			::= {HBox}

			    "int"    :requestedWidth

			    ItemList :content

		  	  | {VBox}

			    "int"    :requestedHeight HAlignment:halign

			    ItemList :content

		  	  | {EmptyBox}

			    "int" :width  "int" :height  "int" :depth

			  | {Rule}

			     "int":width  "int" :height  "int" :depth

		  	  | {TextBox}

			    String:text   "java.awt.Font" :font



ItemList	::= Item*



Item		::= {Glue}

			    "int" :natural  "int" :plus  "int" :minus

		  	  | {BoxItem} 

			    Box   :box



HAlignment	::= {Left} | {HCenter} | {Right}



home \| toc \| install \| usage \| language \| examples \| ref \| api