1 /*
2 
3     This file is part of the Maude 2 interpreter.
4 
5     Copyright 1997-2003 SRI International, Menlo Park, CA 94025, USA.
6 
7     This program is free software; you can redistribute it and/or modify
8     it under the terms of the GNU General Public License as published by
9     the Free Software Foundation; either version 2 of the License, or
10     (at your option) any later version.
11 
12     This program is distributed in the hope that it will be useful,
13     but WITHOUT ANY WARRANTY; without even the implied warranty of
14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15     GNU General Public License for more details.
16 
17     You should have received a copy of the GNU General Public License
18     along with this program; if not, write to the Free Software
19     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
20 
21 */
22 
23 //
24 //      Class for condition fragment supporting equality test.
25 //
26 #ifndef _equalityConditionFragment_hh_
27 #define _equalityConditionFragment_hh_
28 #include "conditionFragment.hh"
29 #include "rhsBuilder.hh"
30 
31 class EqualityConditionFragment : public ConditionFragment
32 {
33   NO_COPYING(EqualityConditionFragment);
34 
35 public:
36   EqualityConditionFragment(Term* lhs, Term* rhs);
37   ~EqualityConditionFragment();
38 
39   void check(VariableInfo& varInfo, NatSet& boundVariables);
40   void preprocess();
41   void compileBuild(VariableInfo& variableInfo, TermBag& availableTerms);
42   void compileMatch(VariableInfo& variableInfo, NatSet& boundUniquely);
43   bool solve(bool findFirst,
44 	     RewritingContext& solution,
45 	     stack<ConditionState*>& state);
46 
47   Term* getLhs() const;
48   Term* getRhs() const;
49 
50   void normalize(bool full);
51   //
52   //	This function exists to enable equality condition fragments to have
53   //	a special operational semantics under rewriting modulo SMT.
54   //
55   void buildInstances(Substitution& substitution, DagNode*& lhs, DagNode*& rhs);
56 
57 #ifdef DUMP
58   void dump(ostream& s, const VariableInfo& variableInfo, int indentLevel);
59 #endif
60 
61 private:
62   Term* lhs;
63   Term* rhs;
64   RhsBuilder builder;
65   int lhsIndex;
66   int rhsIndex;
67 };
68 
69 inline Term*
getLhs() const70 EqualityConditionFragment::getLhs() const
71 {
72   return lhs;
73 }
74 
75 inline Term*
getRhs() const76 EqualityConditionFragment::getRhs() const
77 {
78   return rhs;
79 }
80 
81 inline void
normalize(bool full)82 EqualityConditionFragment::normalize(bool full)
83 {
84   lhs = lhs->normalize(full);
85   rhs = rhs->normalize(full);
86 }
87 
88 #endif
89