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xmlexpr.XMLExpressions Class Reference

List of all members.

Detailed Description

An interactive expression interpreter.

An expression (x = a + b * c, for example) is converted to XML and then evaluated. The expression evaluator supports a symbol table that allows assignment and retrieval of symbol values. Only integer expressions are supported.


Static Public Member Functions

void main (String[] argv)

Static Package Attributes

final String TOP_TAG = "EXPRESSION"
final String NAME_SPACE = "http://www.bearcave.com/expression"
final String PREFIX = "ex"

Member Function Documentation

void xmlexpr.XMLExpressions.main (  String[]  argv  )  [static]
  

00038     {
00039         String line = "";
00040         int len = 0;
00041         ParseExpToXML xmlParse = new ParseExpToXML();
00042         EvalXML evalStmtOrExp = new EvalXML();
00043         DOMParser parser = ParserFactory.newParser( true );
00044         try {
00045             BufferedReader is = new BufferedReader( new InputStreamReader( System.in ) );
00046             do {
00047                 System.out.print("> ");
00048                 line = is.readLine();
00049                 if (line != null ) {
00050                     line = line.trim();
00051                     len = line.length();
00052                     if (len > 0) {
00053                         try {
00054                             String xml = xmlParse.parse( line,
00055                                                          TOP_TAG,
00056                                                          PREFIX,
00057                                                          NAME_SPACE,
00058                                                          "xmlexpr/expression.xsd");
00059                             Integer rslt = evalStmtOrExp.eval(parser, xml.getBytes() );
00060                             if (rslt != null) {
00061                                 System.out.println( rslt );
00062                             }
00063                         } catch (ExpParseException e1) {
00064                             System.out.println("Expression parse error: " + e1 );
00065                         }
00066                     }
00067                 }
00068             } while (line != null && len > 0);
00069         }
00070         catch (IOException e2) {
00071             System.out.println("IOException: " + e2.getMessage());
00072         }
00073     }  // main

Member Data Documentation

final String xmlexpr.XMLExpressions.NAME_SPACE = "http://www.bearcave.com/expression" [static, package]
 

final String xmlexpr.XMLExpressions.PREFIX = "ex" [static, package]
 

final String xmlexpr.XMLExpressions.TOP_TAG = "EXPRESSION" [static, package]
 

The documentation for this class was generated from the following file:
Generated on Sat Aug 28 13:09:44 2004 for XmlExpr by doxygen 1.3.8