/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * 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 General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.vm4brwsr;

 public final class Variable implements CharSequence {

     public static final int TYPE_INT = 0;

     public static final int TYPE_LONG = 1;

     public static final int TYPE_FLOAT = 2;

     public static final int TYPE_DOUBLE = 3;

     public static final int TYPE_REF = 4;

     public static final int LAST_TYPE = TYPE_REF;

     private static final String STACK_VAR_PREFIX = "st";

     private final String name;

     private final int type;

     private final int index;

     private static final char[] TYPE_IDS = { 'I', 'L', 'F', 'D', 'A' };

     private Variable(final String prefix, final int type, final int index) {

         this.name = prefix + TYPE_IDS[type] + index;

         this.type = type;

         this.index = index;

     }

     public static Variable getStackVariable(

             final int type, final int index) {

         // TODO: precreate frequently used variables

         return new Variable(STACK_VAR_PREFIX, type, index);

     }

     public String getName() {

         return name;

     }

     public int getType() {

         return type;

     }

     public int getIndex() {

         return index;

     }

     public boolean isCategory2() {

         return (type == TYPE_LONG) || (type == TYPE_DOUBLE);

     }

     @Override

     public int length() {

         return name.length();

     }

     @Override

     public char charAt(final int index) {

         return name.charAt(index);

     }

     @Override

     public CharSequence subSequence(final int start, final int end) {

         return name.subSequence(start, end);

     }

     @Override

     public int hashCode() {

         return name.hashCode();

     }

     @Override

     public boolean equals(final Object other) {

         if (this == other) {

             return true;

         }

         if (!(other instanceof Variable)) {

             return false;

         }

         return name.equals(((Variable) other).name);

     }

     @Override

     public String toString() {

         return name;

     }

 }