Lexicon.html

Lexicon.java

//  FILE. . . . . /home/hak/ilt/src/ilog/rif/Lexicon.java
//  EDIT BY . . . Hassan Ait-Kaci
//  ON MACHINE. . Latitude407.Ilog.Biz
//  STARTED ON. . Wed May  3 14:37:18 2006

package ilog.rif;

This is a simple lexicon class implementing a very basic token discriminator for the tokenizer in Tokenizer.java. It uses explicit declararations for functional and relation symbols since there is no a priori means to distinguish them - at least not from the information in [RIF] Extensible Design.

Author: Hassan Aït-Kaci

Copyright: © 2006 ILOG, Inc.

Version: Last modified on Wed Sep 20 07:54:55 2006 by hak



import java.util.HashMap;
import java.util.HashSet;

class Lexicon
{

Returns true iff the specified string starts with a question mark, and every other character is alphanumeric or underscore.


  public final static boolean isVariable (String s)
    {
      char c = s.charAt(0);

      if (c != '?')
        return false;

      for (int i=1; i<s.length(); i++)
          {
            c = s.charAt(i);
            if (!Character.isLetterOrDigit(c) && c != '_')
              return false;
          }

      return true;
    }

The following is a store for RCL reserved words.


  public static final HashSet reserved = new HashSet();

The following is a store for RCL function identifiers, associated with a corresponding XML tag.


  public static final HashMap functions = new HashMap();

The following is a store for RCL relation identifiers, associated with a corresponding XML tag.


  public static final HashMap relations = new HashMap();

Returns true iff the specified string is a function identifier.


  public final static boolean isFunction (String word)
    {
      return functions.containsKey(word);
    }

Returns true iff the specified string is a relation identifier.


  public final static boolean isRelation (String word)
    {
      return relations.containsKey(word);
    }

Returns true iff the specified string is a reserved RCL word.


  public final static boolean isReserved (String word)
    {
      return reserved.contains(word);
    }

Declares the specified string as a function identifier whose XML tag is itself.


  static final void function (String word)
    {
      functions.put(word,word);
    }

Declares the specified string as a function identifier, with specified XML tag.


  static final void function (String word, String tag)
    {
      functions.put(word,tag);
    }

Declares the specified string as a relation identifier whose XML tag is itself.


  static final void relation (String word)
    {
      relations.put(word,word);
    }

Declares the specified string as a relation identifier, with specified XML tag.


  static final void relation (String word, String tag)
    {
      relations.put(word,tag);
    }

Declares the specified string as a reserved word.


  static final void reserved (String word)
    {
      reserved.add(word);
    }

Initializes the table of function and relation sysmbols.


  static
    {
      reserved("Exists");
      reserved("Forall");
      reserved("Or");
      reserved("And");
      reserved("Neg");
      reserved("Naf");

      relation("reject");
      relation("accept");
      relation("perishable");
      relation("delivered");
      relation("scheduled");
      relation("timediff");
      relation("greaterThan");
      relation("special");
      relation("purchase");
      relation("knows");
      relation("high");

      function("book");

    }

}

This file was generated on Thu Sep 21 08:10:12 PDT 2006 from file Lexicon.java
by the ilog.language.tools.Hilite Java tool written by Hassan Aït-Kaci