Allow unconstrained variables to be edited

cdglabs · Jan 6, 2015 · 1cb41a0 · 1cb41a0
1 parent ee2f1ef
commit 1cb41a0
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Showing 2 changed files with 43 additions and 2 deletions.
diff --git a/rhea/simplex_solver.cpp b/rhea/simplex_solver.cpp
@@ -140,7 +140,7 @@ solver& simplex_solver::add_constraint_(const constraint& c)
     if (c.is_edit_constraint()) {
         auto& ec = c.as<edit_constraint>();
         const auto& v = ec.var();
-        if (!v.is_external() || (!is_basic_var(v) && !columns_has_key(v)))
+        if (!v.is_external())
             throw edit_misuse(v);
 
         auto i(std::find(edit_info_list_.begin(), edit_info_list_.end(), v));

diff --git a/unit_tests/unit_tests.cpp b/unit_tests/unit_tests.cpp
@@ -289,7 +289,7 @@ BOOST_AUTO_TEST_CASE(simple2_test)
 
     simplex_solver solver;
 
-    BOOST_CHECK_THROW((solver.add_edit_var(x), solver.begin_edit(),
+    BOOST_CHECK_THROW((solver.begin_edit(),
                        solver.suggest_value(x, 100), solver.end_edit()),
                       edit_misuse);
 
@@ -871,3 +871,44 @@ BOOST_AUTO_TEST_CASE(change_weight_test) // issue 33
     solver.change_weight(c1, 3);
     BOOST_CHECK_EQUAL(x.value(), 1);
 }
+
+BOOST_AUTO_TEST_CASE(edit_unconstrained_variable)
+{
+    auto v = variable{ 0 };
+    auto solver = simplex_solver{};
+
+    solver.add_edit_var(v);
+    BOOST_CHECK_EQUAL(v.value(), 0);
+    BOOST_CHECK(solver.is_valid());
+
+    solver.suggest_value(v, 2);
+    solver.resolve();
+    BOOST_CHECK_EQUAL(v.value(), 2);
+    BOOST_CHECK(solver.is_valid());
+}
+
+BOOST_AUTO_TEST_CASE(add_constraints_after_marking_edit_variable)
+{
+    auto v = variable{ 0 };
+    auto solver = simplex_solver{};
+
+    solver.add_edit_var(v);
+    solver.suggest_value(v, 2);
+    solver.resolve();
+    BOOST_CHECK_EQUAL(v.value(), 2);
+    BOOST_CHECK(solver.is_valid());
+
+    // Constraint overrides users desire
+    auto fixed = constraint { v == 42 };
+    solver.add_constraint(fixed);
+    BOOST_CHECK_EQUAL(v.value(), 42);
+    solver.suggest_value(v, 3);
+    solver.resolve();
+    BOOST_CHECK_EQUAL(v.value(), 42);
+    BOOST_CHECK(solver.is_valid());
+
+    // Goes back to last edited value
+    solver.remove_constraint(fixed);
+    BOOST_CHECK_EQUAL(v.value(), 3);
+    BOOST_CHECK(solver.is_valid());
+}