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Class OOLexScanner

java.lang.Object
  |
  +--scanners.OOLexScanner

public class OOLexScanner
extends java.lang.Object
implements oops.parser.Scanner

Lexical analyzer for arithmetic examples.

Author:
Bernd Kuehl, Bernd.Kuehl@informatik.uni-osnabrueck.de, Axel-Tobias Schreiner, axel@informatik.uni-osnabrueck.de, Jan Kraneis, jkraneis@informatik.uni-osnabrueck.de

Field Summary
protected  oolex.Input input
          The input instance.
protected  java.lang.Object node
          node representing token
protected  oops.parser.Set NUMBER
          The Set for the category NUMBER
protected  oops.parser.Parser parser
          The parser.
protected  oolex.Scan scan
          The scanner.
protected  oops.parser.Set tokenSet
          null or lookahead identifying token
 
Constructor Summary
OOLexScanner()
           
 
Method Summary
 boolean advance()
          move on to next token.
 boolean atEnd()
           
 java.lang.Object node()
           
 void scan(java.io.Reader in, oops.parser.Parser parser)
          initialize, read one symbol ahead.
 oops.parser.Set tokenSet()
           
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

tokenSet

protected oops.parser.Set tokenSet
null or lookahead identifying token

node

protected java.lang.Object node
node representing token

input

protected oolex.Input input
The input instance.

NUMBER

protected oops.parser.Set NUMBER
The Set for the category NUMBER

scan

protected final oolex.Scan scan
The scanner.

parser

protected oops.parser.Parser parser
The parser. Used in action methode to set tokenSet.
Constructor Detail

OOLexScanner

public OOLexScanner()
Method Detail

scan

public void scan(java.io.Reader in,
                 oops.parser.Parser parser)
          throws java.io.IOException
initialize, read one symbol ahead.
Specified by:
scan in interface oops.parser.Scanner
Parameters:
parser - is used to screen symbols.

advance

public boolean advance()
                throws java.io.IOException
move on to next token.
Specified by:
advance in interface oops.parser.Scanner
Returns:
false if atEnd() becomes true.

atEnd

public boolean atEnd()
Specified by:
atEnd in interface oops.parser.Scanner
Returns:
true if positioned beyond tokens.

tokenSet

public oops.parser.Set tokenSet()
Specified by:
tokenSet in interface oops.parser.Scanner
Returns:
single-element lookahead set, null for unidentifiable token.

node

public java.lang.Object node()
Specified by:
node in interface oops.parser.Scanner
Returns:
node corresponding to token.

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object
Returns:
a String representation.