Keyword.java

/*
** Module   : Keyword.java
** Abstract : encapsulates a language keyword
**
** Copyright (c) 2004-2017, Golden Code Development Corporation.
**
** -#- -I- --Date-- -T- --JPRM-- ----------------Description-----------------
** 001 GES 20041105 ADD   @18645 First version implementing a bean-like
**                               interface.  Only designed to contain some
**                               data, there is no processing being done.
** 002 GES 20041116 CHG   @18646 Added generic support for containing an
**                               arbitrary object reference to user-specified
**                               data.
*/ 
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
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**   Affero GPL version 3 and may not be removed by you.
** 
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*/

package com.goldencode.p2j.uast;

/**
 * Encapsulates all data associated with a language keyword.  Instances of 
 * this class can be stored in a dictionary of type 
 * <code>KeywordDictionary</code>. This class provides sufficient data about
 * the keyword to implement reserved/unreserved keywords and matching on a
 * set of valid keyword abbreviations.
 * <p>
 * The interface is designed to provide data access and the class does not
 * implement any real function other than the storage and retrieval of
 * the associated data members.
 * 
 * @author GES
 * @version 1.0.1
 */
public class Keyword
{
   /** Full, literal text form of the keyword. */
   private String fullText;
   
   /**
    * Minimum number of characters needed to match the keyword.  Must be  
    * a non-negative integer.  If set to 0, this disables abbreviation 
    * processing.  Otherwise, it specifies the number of leftmost characters 
    * that must be an identical match to match this keyword.
    */
   private int minChars;
   
   /**
    * The integer token type associated with this keyword in the Parser
    * and Lexer.  This usually will correspond to an "imaginary" token
    * created in a tokens {} clause for ANTLR.
    */
   private int tokenType;
   
   /** The keyword is a reserved keyword in the source language. */
   private boolean reserved;
   
   /**
    * Arbitrary user-specified data to be associated with this keyword.
    * This data is not used or modified in any way, but is simply provided
    * to the caller upon request.
    */
   private Object extra;
   
   /**
    * Constructs a keyword with the minimum number of valid fields.
    * 
    * @param   text    
    *          Full text form of the keyword.
    * @param   min
    *          Minimum number of leftmost characters which will still match
    *          the full text.  Set to 0 to disable abbreviation support.
    * @param   type
    *          Constant representing the Lexer or Parser token type
    *          associated with this keyword.
    * @param   reserved
    *          If true, this keyword is a reserved keyword and may not be
    *          used in user-defined symbols.  If false, this is an
    *          unreserved keyword.
    */
   public Keyword(String   text,
                  int      min,
                  int      type,
                  boolean  reserved)
   {
      fullText      = text;
      minChars      = min;
      tokenType     = type;
      this.reserved = reserved;
   }
   
   /**
    * Constructs a keyword with all possible fields.
    * 
    * @param   text    
    *          Full text form of the keyword.
    * @param   min
    *          Minimum number of leftmost characters which will still match
    *          the full text.  Set to 0 to disable abbreviation support.
    * @param   type
    *          Constant representing the Lexer or Parser token type
    *          associated with this keyword.
    * @param   reserved
    *          If true, this keyword is a reserved keyword and may not be
    *          used in user-defined symbols.  If false, this is an
    *          unreserved keyword.
    * @param   extra
    *          User-defined object that is associated with this keyword. This
    *          object is stored but not altered in any way.
    */   
   public Keyword(String   text,
                  int      min,
                  int      type,
                  boolean  reserved,
                  Object   extra)
   {
      fullText      = text;
      minChars      = min;
      tokenType     = type;
      this.reserved = reserved;
      this.extra    = extra;
   }
      
   /**
    * Converts a <code>Keyword</code> object into a <code>String</code>
    * representation.
    * 
    * @see    java.lang.Object#toString
    */
   public String toString()
   {
      return new String("'"                + 
                        fullText           + 
                        "' minChars = "    + 
                        minChars           +
                        "; tokenType = "   + 
                        tokenType          +
                        "; reserved = "    +
                        reserved);
   }
      
   /** 
    * Returns the full text of the keyword.
    *
    * @return   Full text of the keyword.
    */
   public String getFullText()   
   {
      return fullText;
   }
   
   /** 
    * Sets the full text of the keyword.
    *
    * @param   text
    *          The text to seet as the keyword's full text.
    */
   public void setFullText(String text)   
   {
      fullText = text;
   }
      
   /**
    * Returns the minimum number of characters used in abbreviations.
    *
    * @return   Minimum number of left-most characters that still is a match.
    */
   public int getMinChars()
   {
      return minChars;
   }
   
   /**
    * Sets the minimum number of characters used in abbreviations.
    *
    * @param   min
    *          Minimum number of left-most characters that still is a match.
    */
   public void setMinChars(int min)
   {
      minChars = min;
   }
   
   /**
    * Returns the token type associated with this keyword by the Lexer and 
    * Parser.
    *
    * @return   The token type.
    */
   public int getTokenType()
   {
      return tokenType;
   }
   
   /**
    * Sets the token type associated with this keyword by the Lexer and 
    * Parser.
    *
    * @param   type
    *          The token type.
    */   
   public void setTokenType(int type)
   {
      tokenType = type;
   }
   
   /**
    * Returns the reserved keyword status of this keyword. 
    *
    * @return   The keyword's reserved status.
    */
   public boolean isReserved()
   { 
      return reserved;
   }
   
   /**
    * Sets the reserved keyword status of this keyword. 
    *
    * @param   reserved
    *          The keyword's reserved status.
    */   
   public void setReserved(boolean reserved)
   { 
      this.reserved = reserved;
   }   
   
   /** 
    * Returns the user-defined object associated with this keyword.
    *
    * @return   User-defined object.
    */
   public Object getExtra()
   {
      return extra;
   }
   
   /**
    * Sets the user-defined object associated with this keyword. 
    *
    * @param   extra
    *          User-defined object.
    */
   public void setExtra(Object extra)
   {
      this.extra = extra;
   }   
}