001/* An evaluation scope that consists of a list of nested scopes.
002
003 Copyright (c) 2002-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026
027
028 */
029package ptolemy.data.expr;
030
031import java.util.HashSet;
032import java.util.Iterator;
033import java.util.List;
034import java.util.Set;
035
036import ptolemy.graph.InequalityTerm;
037import ptolemy.kernel.util.IllegalActionException;
038
039//////////////////////////////////////////////////////////////////////////
040//// NestedScope
041
042/**
043 An implementation of ParserScope that consists of a list of nested scopes.
044 A lookup starts from the first scope in the list, and proceeds through the
045 list until a mapping is found.
046
047 @author Xiaojun Liu
048 @version $Id$
049 @since Ptolemy II 2.1
050 @Pt.ProposedRating Red (liuxj)
051 @Pt.AcceptedRating Red (liuxj)
052 */
053public class NestedScope implements ParserScope {
054    /** Construct a new scope that consists of the given list of scopes.
055     *  @param scopeList The list of scopes.
056     */
057    public NestedScope(List scopeList) {
058        _scopeList = scopeList;
059    }
060
061    /** Look up and return the value with the specified name in the
062     *  scope. Start from the first scope in the list supplied to the
063     *  constructor. If a value is found, return the value, otherwise
064     *  continue to look up through the list. Return null if no mapping
065     *  is defined in any scope in the list.
066     *  @return The token associated with the given name in the scope.
067     *  @exception IllegalActionException If a value in the scope
068     *  exists with the given name, but cannot be evaluated.
069     */
070    @Override
071    public ptolemy.data.Token get(String name) throws IllegalActionException {
072        Iterator scopes = _scopeList.iterator();
073
074        while (scopes.hasNext()) {
075            ParserScope scope = (ParserScope) scopes.next();
076            ptolemy.data.Token result = scope.get(name);
077
078            if (result != null) {
079                return result;
080            }
081        }
082
083        return null;
084    }
085
086    /** Look up and return the type of the value with the specified
087     *  name in the scope. Return null if the name is not defined in
088     *  this scope.
089     *  @return The token associated with the given name in the scope.
090     *  @exception IllegalActionException If a value in the scope
091     *  exists with the given name, but cannot be evaluated.
092     */
093    @Override
094    public ptolemy.data.type.Type getType(String name)
095            throws IllegalActionException {
096        Iterator scopes = _scopeList.iterator();
097
098        while (scopes.hasNext()) {
099            ParserScope scope = (ParserScope) scopes.next();
100            ptolemy.data.type.Type result = scope.getType(name);
101
102            if (result != null) {
103                return result;
104            }
105        }
106
107        return null;
108    }
109
110    /** Look up and return the type term for the specified name
111     *  in the scope. Return null if the name is not defined in this
112     *  scope, or is a constant type.
113     *  @return The InequalityTerm associated with the given name in
114     *  the scope.
115     *  @exception IllegalActionException If a value in the scope
116     *  exists with the given name, but cannot be evaluated.
117     */
118    @Override
119    public ptolemy.graph.InequalityTerm getTypeTerm(String name)
120            throws IllegalActionException {
121        Iterator scopes = _scopeList.iterator();
122
123        while (scopes.hasNext()) {
124            ParserScope scope = (ParserScope) scopes.next();
125            InequalityTerm result = scope.getTypeTerm(name);
126
127            if (result != null) {
128                return result;
129            }
130        }
131
132        return null;
133    }
134
135    /** Return the list of identifiers within the scope.
136     *  @return The union of the identifierSets of the contained scopes.
137     *  @exception IllegalActionException If the identifierSet()
138     *  method of a contained scope throws it.
139     */
140    @Override
141    public Set identifierSet() throws IllegalActionException {
142        Set set = new HashSet();
143
144        for (Iterator scopes = _scopeList.iterator(); scopes.hasNext();) {
145            ParserScope scope = (ParserScope) scopes.next();
146            set.addAll(scope.identifierSet());
147        }
148
149        return set;
150    }
151
152    private List _scopeList;
153}