1 package org.sentrysoftware.jawk.frontend;
2
3 /*-
4 * ╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲
5 * Jawk
6 * ჻჻჻჻჻჻
7 * Copyright (C) 2006 - 2023 Sentry Software
8 * ჻჻჻჻჻჻
9 * This program is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser General Public License as
11 * published by the Free Software Foundation, either version 3 of the
12 * License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Lesser Public License for more details.
18 *
19 * You should have received a copy of the GNU General Lesser Public
20 * License along with this program. If not, see
21 * <http://www.gnu.org/licenses/lgpl-3.0.html>.
22 * ╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱
23 */
24
25 import java.io.PrintStream;
26
27 import org.sentrysoftware.jawk.intermediate.AwkTuples;
28
29 /**
30 * A Jawk abstract syntax tree node. This provides
31 * an appropriate public interface to the abstract
32 * syntax tree.
33 *
34 * @author Danny Daglas
35 */
36 public interface AwkSyntaxTree {
37
38 /**
39 * Dump a meaningful text representation of this
40 * abstract syntax tree node to the output (print)
41 * stream. Either it is called directly by the
42 * application program, or it is called by the
43 * parent node of this tree node.
44 *
45 * @param ps The print stream to dump the text
46 * representation.
47 */
48 void dump(PrintStream ps);
49
50 /**
51 * Apply semantic checks to this node. The default
52 * implementation is to simply call semanticAnalysis()
53 * on all the children of this abstract syntax tree node.
54 * Therefore, this method must be overridden to provide
55 * meaningful semantic analysis / checks.
56 */
57 void semanticAnalysis();
58
59 /**
60 * Appends tuples to the AwkTuples list
61 * for this abstract syntax tree node. Subclasses
62 * must implement this method.
63 * <p>
64 * This is called either by the main program to generate a full
65 * list of tuples for the abstract syntax tree, or it is called
66 * by other abstract syntax tree nodes in response to their
67 * attempt at populating tuples.
68 *
69 * @param tuples The tuples to populate.
70 * @return The number of items left on the operand stack after
71 * these tuples have executed.
72 */
73 int populateTuples(AwkTuples tuples);
74 }