1 ////////////////////////////////////////////////////////////////////////////////
2 // MillScript: an Open Spice interpreter and batch website creation tool
3 // Copyright (C) 2001-2004 Open World Ltd
4 //
5 // This file is part of MillScript.
6 //
7 // MillScript is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU General Public License as published by the Free
9 // Software Foundation; either version 2 of the License, or (at your option)
10 // any later version.
11 //
12 // MillScript is distributed in the hope that it will be useful, but WITHOUT
13 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 // more details.
16 //
17 // You should have received a copy of the GNU General Public License along with
18 // MillScript; if not, write to the Free Software Foundation, Inc., 59 Temple
19 // Place, Suite 330, Boston, MA 02111-1307 USA
20 ////////////////////////////////////////////////////////////////////////////////
21 package org.millscript.millscript.action;
22
23 import org.millscript.millscript.vm.Machine;
24
25 /**
26 * This class is the base of all unary actions, i.e. those that operate on a
27 * single value.
28 */
29 public abstract class UnaryOpAction extends Action {
30
31 /**
32 * The action for this unary operation.
33 */
34 private final Action action;
35
36 /**
37 * Constructs a new unary action, for the specified action.
38 *
39 * @param a the single action
40 */
41 protected UnaryOpAction( final Action a ) {
42 this.action = a;
43 }
44
45 /**
46 * Performs this binary action on the specified value.
47 *
48 * @param x the unary value
49 * @return the result of this unary action
50 */
51 public abstract Object perform( final Object x );
52
53 /**
54 * @see org.millscript.millscript.action.Action#action(org.millscript.millscript.vm.Machine)
55 */
56 @Override
57 public final void action( final Machine mc ) {
58 mc.pushObject( perform( action.act1( mc ) ) );
59 }
60
61 }