/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.shell.bjorne;
import org.jnode.shell.CommandRunnable;
import org.jnode.shell.CommandShell;
import org.jnode.shell.CommandThread;
import org.jnode.shell.CommandThreadImpl;
import org.jnode.shell.ShellException;
/**
* LoopCommandNode is the parse tree node class for 'until' and 'while' loop statements.
*
* @author crawley@jnode.org
*/
public class LoopCommandNode extends CommandNode {
private final CommandNode cond;
private final CommandNode body;
/**
* Construct the LoopCommandNode
* @param nodeType either {@link BjorneInterpreter#CMD_WHILE} or {@link BjorneInterpreter#CMD_UNTIL}.
* @param cond the loop's condition CommandNode
* @param body the loop's body CommandNode
*/
public LoopCommandNode(int nodeType, CommandNode cond, CommandNode body) {
super(nodeType);
this.body = body;
this.cond = cond;
}
/**
* Get the loop's 'body' node.
* @return the 'body' node.
*/
public CommandNode getBody() {
return body;
}
/**
* Get the loop's 'condition' node
* @return the 'condition' node.
*/
public CommandNode getCond() {
return cond;
}
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("LoopCommand{").append(super.toString());
sb.append(",cond=").append(cond);
sb.append(",body=").append(body);
sb.append('}');
return sb.toString();
}
public int execute(BjorneContext context) throws ShellException {
try {
int rc = 0;
context.evaluateRedirectionsAndPushHolders(getRedirects());
while (true) {
rc = cond.execute(context);
if (rc != 0 && getNodeType() == BjorneInterpreter.CMD_WHILE ||
rc == 0 && getNodeType() == BjorneInterpreter.CMD_UNTIL) {
break;
}
try {
if (body != null) {
body.execute(context);
}
} catch (BjorneControlException ex) {
int control = ex.getControl();
if (control == BjorneInterpreter.BRANCH_BREAK ||
control == BjorneInterpreter.BRANCH_CONTINUE) {
if (ex.getCount() > 1) {
ex.decrementCount();
throw ex;
}
if (control == BjorneInterpreter.BRANCH_BREAK) {
break;
} else {
continue;
}
} else {
throw ex;
}
}
}
if ((getFlags() & BjorneInterpreter.FLAG_BANG) != 0) {
rc = (rc == 0) ? -1 : 0;
}
return rc;
} finally {
context.popHolders();
}
}
@Override
public CommandThread fork(CommandShell shell, final BjorneContext context)
throws ShellException {
CommandRunnable cr = new BjorneSubshellRunner(context) {
@Override
public int doRun() throws ShellException {
return LoopCommandNode.this.execute(context);
}
};
return new CommandThreadImpl(cr, context.getName());
}
}