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.loaders;
22
23 import org.millscript.millscript.expr.Expr;
24
25 import java.io.IOException;
26
27 /**
28 * This is the base class of all single expression loaders in MillScript. An
29 * expression loader compiles the contents of the file as a single expression,
30 * which does not make any bindings. e.g. a MillScript <code>fun</code> object,
31 * or a string.
32 */
33 public abstract class ExprLoader extends ValueLoader {
34
35 /**
36 * Causes this loader to load it's expression.
37 *
38 * @return the expression that was loaded
39 * @throws IOException if something goes wrong reading from the source
40 */
41 public abstract Expr loadExpr() throws IOException;
42
43 /**
44 * @see org.millscript.millscript.loaders.Loader#loadValue()
45 */
46 @Override
47 public Object loadValue() throws IOException {
48 Expr e = loadExpr();
49 return this.pack.getCompilerState().compileExprToValue( e );
50 }
51
52 }