streamline pb solver interface and naming after removal of xor

src/sat/smt/pb_constraint.cpp

@@ -0,0 +1,71 @@
+/*++
+Copyright (c) 2017 Microsoft Corporation
+
+Module Name:
+
+    ba_constraint.cpp
+
+Abstract:
+ 
+    Interface for constraints.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2017-01-30
+
+--*/
+
+#include "sat/smt/pb_constraint.h"
+
+namespace pb {
+
+    unsigned constraint::fold_max_var(unsigned w) const {
+        if (lit() != sat::null_literal) w = std::max(w, lit().var());
+        for (unsigned i = 0; i < size(); ++i) w = std::max(w, get_lit(i).var());
+        return w;
+    }
+
+    std::ostream& operator<<(std::ostream& out, constraint const& cnstr) {
+        if (cnstr.lit() != sat::null_literal) out << cnstr.lit() << " == ";
+        return cnstr.display(out);
+    }
+
+    bool constraint::is_watched(solver_interface const& s, literal lit) const {
+        return s.get_wlist(~lit).contains(sat::watched(cindex()));
+    }
+
+    void constraint::unwatch_literal(solver_interface& s, literal lit) {
+        sat::watched w(cindex());
+        s.get_wlist(~lit).erase(w);
+        SASSERT(!is_watched(s, lit));
+    }
+
+    void constraint::watch_literal(solver_interface& s, literal lit) {
+        if (is_pure() && lit == ~this->lit()) return;
+        SASSERT(!is_watched(s, lit));
+        sat::watched w(cindex());
+        s.get_wlist(~lit).push_back(w);
+    }
+
+    void constraint::nullify_tracking_literal(solver_interface& s) {
+        if (lit() != sat::null_literal) {
+            unwatch_literal(s, lit());
+            unwatch_literal(s, ~lit());
+            nullify_literal();
+        }
+    }
+
+    bool constraint::well_formed() const {
+        uint_set vars;
+        if (lit() != sat::null_literal) vars.insert(lit().var());
+        for (unsigned i = 0; i < size(); ++i) {
+            bool_var v = get_lit(i).var();
+            if (vars.contains(v)) return false;
+            if (get_coeff(i) > k()) return false;
+            vars.insert(v);
+        }
+        return true;
+    }
+
+
+}