1 /********************************************************************************
2 *
3 * Copyright (c) 2008 Fujitsu Services Ltd.
4 *
5 * Author: Nick Battle
6 *
7 * This file is part of VDMJ.
8 *
9 * VDMJ is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation, either version 3 of the License, or
12 * (at your option) any later version.
13 *
14 * VDMJ 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 Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with VDMJ. If not, see <http://www.gnu.org/licenses/>.
21 *
22 ******************************************************************************/
23
24 package org.overturetool.vdmj.expressions;
25
26 import org.overturetool.vdmj.lex.LexLocation;
27 import org.overturetool.vdmj.runtime.Context;
28 import org.overturetool.vdmj.runtime.ValueException;
29 import org.overturetool.vdmj.typechecker.Environment;
30 import org.overturetool.vdmj.typechecker.NameScope;
31 import org.overturetool.vdmj.types.MapType;
32 import org.overturetool.vdmj.types.SetType;
33 import org.overturetool.vdmj.types.Type;
34 import org.overturetool.vdmj.types.TypeList;
35 import org.overturetool.vdmj.types.UnknownType;
36 import org.overturetool.vdmj.values.SetValue;
37 import org.overturetool.vdmj.values.Value;
38 import org.overturetool.vdmj.values.ValueMap;
39 import org.overturetool.vdmj.values.ValueSet;
40
41 public class MapDomainExpression extends UnaryExpression
42 {
43 private static final long serialVersionUID = 1L;
44
45 public MapDomainExpression(LexLocation location, Expression exp)
46 {
47 super(location, exp);
48 }
49
50 @Override
51 public String toString()
52 {
53 return "(dom " + exp + ")";
54 }
55
56 @Override
57 public Type typeCheck(Environment env, TypeList qualifiers, NameScope scope)
58 {
59 Type etype = exp.typeCheck(env, null, scope);
60
61 if (!etype.isMap())
62 {
63 report(3120, "Argument to 'dom' is not a map");
64 return new UnknownType(location);
65 }
66
67 MapType mt = etype.getMap();
68 return new SetType(location, mt.from);
69 }
70
71 @Override
72 public Value eval(Context ctxt)
73 {
74 breakpoint.check(location, ctxt);
75
76 try
77 {
78 ValueMap map = exp.eval(ctxt).mapValue(ctxt);
79 ValueSet result = new ValueSet();
80 result.addAll(map.keySet());
81 return new SetValue(result);
82 }
83 catch (ValueException e)
84 {
85 return abort(e);
86 }
87 }
88
89 @Override
90 public String kind()
91 {
92 return "dom";
93 }
94 }