Add function _parse_str for list.

tests/test-mlist.c

@@ -237,14 +237,33 @@ static void test_mpz(void)
   M_LET(str, STRING_OPLIST) {
     list_mpz_get_str(str, v, false);
     assert (string_cmp_str (str, "[]") == 0);
+    const char *sp;
+    b = list_mpz_parse_str(list2, string_get_cstr(str), &sp);
+    assert(b);
+    assert(*sp == 0);
+    assert(list_mpz_equal_p(v, list2));
+
     my_mpz_set_ui (z, 17);
     list_mpz_push_back (v, z);
     list_mpz_get_str(str, v, false);
     assert (string_cmp_str (str, "[17]") == 0);
+    b = list_mpz_parse_str(list2, string_get_cstr(str), &sp);
+    assert(b);
+    assert(*sp == 0);
+    assert(list_mpz_equal_p(v, list2));
+
     my_mpz_set_ui (z, 42);
     list_mpz_push_back (v, z);
     list_mpz_get_str(str, v, true);
     assert (string_cmp_str (str, "[17][42,17]") == 0);
+    b = list_mpz_parse_str(list2, string_get_cstr(str), &sp);
+    assert(b);
+    assert(strcmp(sp, "[42,17]") == 0);
+    assert(!list_mpz_equal_p(v, list2));
+    b = list_mpz_parse_str(list2, sp, &sp);
+    assert(b);
+    assert(strcmp(sp, "") == 0);
+    assert(list_mpz_equal_p(v, list2));
   }
   
   list_mpz_clear(v);