/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* jflex *
* Copyright (C) 1998-2004 Gerwin Klein <lsf@jflex.de> *
* All rights reserved. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License. See the file *
* COPYRIGHT for more information. *
* *
* 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; if not, write to the Free Software Foundation, Inc., *
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *
* *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
package weka.core.parser.JFlex;
/**
* HiLowEmitter
*
* @author Gerwin Klein
* @version $Revision: 1.1 $, $Date: 2008/05/09 09:14:10 $
*/
public class HiLowEmitter extends PackEmitter {
/** number of entries in expanded array */
private int numEntries;
/**
* Create new emitter for values in [0, 0xFFFFFFFF] using hi/low encoding.
*
* @param name the name of the generated array
*/
public HiLowEmitter(String name) {
super(name);
}
/**
* Emits hi/low pair unpacking code for the generated array.
*
* @see JFlex.PackEmitter#emitUnPack()
*/
public void emitUnpack() {
// close last string chunk:
println("\";");
nl();
println(" private static int [] zzUnpack"+name+"() {");
println(" int [] result = new int["+numEntries+"];");
println(" int offset = 0;");
for (int i = 0; i < chunks; i++) {
println(" offset = zzUnpack"+name+"("+constName()+"_PACKED_"+i+", offset, result);");
}
println(" return result;");
println(" }");
nl();
println(" private static int zzUnpack"+name+"(String packed, int offset, int [] result) {");
println(" int i = 0; /* index in packed string */");
println(" int j = offset; /* index in unpacked array */");
println(" int l = packed.length();");
println(" while (i < l) {");
println(" int high = packed.charAt(i++) << 16;");
println(" result[j++] = high | packed.charAt(i++);");
println(" }");
println(" return j;");
println(" }");
}
/**
* Emit one value using two characters.
*
* @param val the value to emit
* @prec 0 <= val <= 0xFFFFFFFF
*/
public void emit(int val) {
numEntries+= 1;
breaks();
emitUC(val >> 16);
emitUC(val & 0xFFFF);
}
}