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The source code

/*
 * IfFunction.java - if/else statement
 * Copyright (C) 2000 Romain Guy
 * romain.guy@jext.org
 * http://www.jext.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; either version 2
 * of the License, or 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 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 org.jext.dawn.test;

import java.io.IOException;
import java.io.StreamTokenizer;

import org.jext.dawn.*;

/**
 * This class provides an implementation of the if/else statement.
* Usage:
* if [condition] then [code] else [code] end
* else is optional. * @author Romain Guy */ public class IfFunction extends Function { public IfFunction() { super("if"); } public void invoke(DawnParser parser) throws DawnRuntimeException { StreamTokenizer st = parser.getStream(); StringBuffer buf = new StringBuffer(); try // LONG LONG TRY { out: for( ; ; ) { switch(st.nextToken()) { case StreamTokenizer.TT_EOL: buf.append('\n'); break; case StreamTokenizer.TT_EOF: throw new DawnRuntimeException(this, parser, "if without then"); case StreamTokenizer.TT_WORD: if (st.sval.equals("then")) break out; buf.append(' ' + st.sval); break; case '"': case '\'': buf.append(" \"" + DawnUtilities.unescape(st.sval) + "\""); break; case '-': buf.append(" -"); break; case StreamTokenizer.TT_NUMBER: buf.append(" " + st.nval); } } int innerTest = 0; boolean elseStatement = false; StringBuffer ifBuffer = new StringBuffer(); StringBuffer elseBuffer = new StringBuffer(); out2: for( ; ; ) { switch(st.nextToken()) { case StreamTokenizer.TT_EOL: (elseStatement ? elseBuffer : ifBuffer).append('\n'); break; case StreamTokenizer.TT_EOF: throw new DawnRuntimeException(this, parser, "if without else or end"); case StreamTokenizer.TT_WORD: if (st.sval.equals("if")) innerTest++; else if (st.sval.equals("else")) { if (innerTest == 0) { elseStatement = true; break; } } else if (st.sval.equals("end")) { if (innerTest > 0) innerTest--; else break out2; } (elseStatement ? elseBuffer : ifBuffer).append(' ' + st.sval); break; case '"': case '\'': (elseStatement ? elseBuffer : ifBuffer).append(" \"" + DawnUtilities.unescape(st.sval) + "\""); break; case '-': (elseStatement ? elseBuffer : ifBuffer).append(" -"); break; case StreamTokenizer.TT_NUMBER: (elseStatement ? elseBuffer : ifBuffer).append(" " + st.nval); } } Function function = parser.createOnFlyFunction(buf.toString()); function.invoke(parser); int bool = (int) parser.popNumber(); if (bool >= 1) { if (ifBuffer.length() != 0) { function = parser.createOnFlyFunction(ifBuffer.toString()); function.invoke(parser); } } else { if (elseBuffer.length() != 0) { function = parser.createOnFlyFunction(elseBuffer.toString()); function.invoke(parser); } } } catch (IOException ioe) { throw new DawnRuntimeException(this, parser, "unexpected error occured during parsing"); } } } // End of IfFunction.java
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