added some checks for subs() behavior
[ginac.git] / check / exam_misc.cpp
index 5613b3756edc81acf3b390f057fa9f9e9ff08212..849dc5adabd666ba1009e68ca18922fe926bc06b 100644 (file)
@@ -199,6 +199,33 @@ static unsigned exam_operator_semantics(void)
        return result;
 }
 
+/* This checks whether subs() works as intended in some special cases. */
+static unsigned exam_subs(void)
+{
+       unsigned result = 0;
+       symbol x("x");
+       ex e1, e2;
+
+       // This used to fail in GiNaC 1.0.5 because it first substituted
+       // x+1 -> (x-1)+1 -> x, and then substituted again x -> x-1, giving
+       // the wrong result
+       e1 = x+1;
+       e2 = e1.subs(x == x-1);
+       if (!e2.is_equal(x)) {
+               clog << "(x+1).subs(x==x-1) erroneously returned " << e2 << " instead of x" << endl;
+               ++result;
+       }
+
+       e1 = sin(1+sin(x));
+       e2 = e1.subs(sin(wild()) == cos(wild()));
+       if (!e2.is_equal(cos(1+cos(x)))) {
+               clog << "sin(1+sin(x)).subs(sin($1)==cos($1)) erroneously returned " << e2 << " instead of cos(1+cos(x))" << endl;
+               ++result;
+       }
+
+       return result;
+}
+
 unsigned exam_misc(void)
 {
        unsigned result = 0;
@@ -211,6 +238,7 @@ unsigned exam_misc(void)
        result += exam_expand_power(); cout << '.' << flush;
        result += exam_sqrfree(); cout << '.' << flush;
        result += exam_operator_semantics(); cout << '.' << flush;
+       result += exam_subs(); cout << '.' << flush;
        
        if (!result) {
                cout << " passed " << endl;