01: /*******************************************************************************
02: * Copyright (c) 2004, 2006 IBM Corporation and others.
03: * All rights reserved. This program and the accompanying materials
04: * are made available under the terms of the Eclipse Public License v1.0
05: * which accompanies this distribution, and is available at
06: * http://www.eclipse.org/legal/epl-v10.html
07: *
08: * Contributors:
09: * IBM Corporation - initial API and implementation
10: *******************************************************************************/package org.eclipse.jdt.core.dom;
11:
12: /**
13: * Descriptor for a child list property of an AST node.
14: * A child list property is one whose value is a list of
15: * {@link ASTNode}.
16: *
17: * @see org.eclipse.jdt.core.dom.ASTNode#getStructuralProperty(StructuralPropertyDescriptor)
18: * @since 3.0
19: */
20: public final class ChildListPropertyDescriptor extends
21: StructuralPropertyDescriptor {
22:
23: /**
24: * Element type. For example, for a node type like
25: * CompilationUnit, the "imports" property is ImportDeclaration.class.
26: * <p>
27: * Field is private, but marked package-visible for fast
28: * access from ASTNode.
29: * </p>
30: */
31: final Class elementType;
32:
33: /**
34: * Indicates whether a cycle is possible.
35: * <p>
36: * Field is private, but marked package-visible for fast
37: * access from ASTNode.
38: * </p>
39: */
40: final boolean cycleRisk;
41:
42: /**
43: * Creates a new child list property descriptor with the given property id.
44: * Note that this constructor is declared package-private so that
45: * property descriptors can only be created by the AST
46: * implementation.
47: *
48: * @param nodeClass concrete AST node type that owns this property
49: * @param propertyId the property id
50: * @param elementType the element type of this property
51: * @param cycleRisk <code>true</code> if this property is at
52: * risk of cycles, and <code>false</code> if there is no worry about cycles
53: */
54: ChildListPropertyDescriptor(Class nodeClass, String propertyId,
55: Class elementType, boolean cycleRisk) {
56: super (nodeClass, propertyId);
57: if (elementType == null) {
58: throw new IllegalArgumentException();
59: }
60: this .elementType = elementType;
61: this .cycleRisk = cycleRisk;
62: }
63:
64: /**
65: * Returns the element type of this list property.
66: * <p>
67: * For example, for a node type like CompilationUnit,
68: * the "imports" property returns <code>ImportDeclaration.class</code>.
69: * </p>
70: *
71: * @return the element type of the property
72: */
73: public final Class getElementType() {
74: return this .elementType;
75: }
76:
77: /**
78: * Returns whether this property is vulnerable to cycles.
79: * <p>
80: * A property is vulnerable to cycles if a node of the owning
81: * type (that is, the type that owns this property) could legally
82: * appear in the AST subtree below this property. For example,
83: * the body property of a
84: * {@link MethodDeclaration} node
85: * admits a body which might include statement that embeds
86: * another {@link MethodDeclaration} node.
87: * On the other hand, the name property of a
88: * MethodDeclaration node admits only names, and thereby excludes
89: * another MethodDeclaration node.
90: * </p>
91: *
92: * @return <code>true</code> if cycles are possible,
93: * and <code>false</code> if cycles are impossible
94: */
95: public final boolean cycleRisk() {
96: return this.cycleRisk;
97: }
98: }
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