add visitor example, fix double conversion

Signed-off-by: Nikolaj Bjorner <[email protected]>
Z3Prover · Oct 11, 2019 · a990e7f · a990e7f
1 parent 4fc64ab
commit a990e7f
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Showing 2 changed files with 29 additions and 12 deletions.
diff --git a/examples/c++/example.cpp b/examples/c++/example.cpp
@@ -802,19 +802,27 @@ void tactic_qe() {
     std::cout << s.get_model() << "\n";
 }
 
-void visit(expr const & e) {
+void visit(std::vector<bool>& visited, expr const & e) {
+    if (visited.size() <= e.id()) {
+        visited.resize(e.id()+1, false);
+    }
+    if (visited[e.id()]) {
+        return;
+    }
+    visited[e.id()] = true;
+
     if (e.is_app()) {
         unsigned num = e.num_args();
         for (unsigned i = 0; i < num; i++) {
-            visit(e.arg(i));
+            visit(visited, e.arg(i));
         }
         // do something
         // Example: print the visited expression
         func_decl f = e.decl();
         std::cout << "application of " << f.name() << ": " << e << "\n";
     }
     else if (e.is_quantifier()) {
-        visit(e.body());
+        visit(visited, e.body());
         // do something
     }
     else { 
@@ -830,12 +838,13 @@ void tst_visit() {
     expr x = c.int_const("x");
     expr y = c.int_const("y");
     expr z = c.int_const("z");
-    expr f = x*x - y*y >= 0;
-
-    visit(f);
+    expr f = x*x + x*x - y*y >= 0;
+    std::vector<bool> visited;
+    visit(visited, f);
 }
 
 void tst_numeral() {
+    std::cout << "numeral example\n";
     context c;
     expr x = c.real_val("1/3");
     double d = 0;

diff --git a/src/api/api_numeral.cpp b/src/api/api_numeral.cpp
@@ -239,13 +239,21 @@ extern "C" {
         expr* e = to_expr(a);
         fpa_util & fu = mk_c(c)->fpautil();
         scoped_mpf tmp(fu.fm());
-        if (!mk_c(c)->fpautil().is_numeral(e, tmp) ||
-            tmp.get().get_ebits() > 11 ||
-            tmp.get().get_sbits() > 53) {
-            SET_ERROR_CODE(Z3_INVALID_ARG, nullptr);
-            return NAN;
+        if (mk_c(c)->fpautil().is_numeral(e, tmp)) {
+            if (tmp.get().get_ebits() > 11 ||
+                tmp.get().get_sbits() > 53) {
+                SET_ERROR_CODE(Z3_INVALID_ARG, nullptr);
+                return NAN;
+            }
+            return fu.fm().to_double(tmp);
         }
-        return fu.fm().to_double(tmp);
+        rational r;
+        arith_util & u = mk_c(c)->autil();
+        if (u.is_numeral(e, r)) {
+            return r.get_double();
+        }
+        SET_ERROR_CODE(Z3_INVALID_ARG, nullptr);
+        return 0.0;
     }
 
     Z3_string Z3_API Z3_get_numeral_decimal_string(Z3_context c, Z3_ast a, unsigned precision) {