Fix up some error handling

include/chaiscript/language/chaiscript_common.hpp

@@ -647,8 +647,6 @@ namespace chaiscript
       /// Special type for returned values
       struct Return_Value {
         Boxed_Value retval;
-
-        explicit Return_Value(Boxed_Value t_return_value) : retval(std::move(t_return_value)) { }
       };
 
 

include/chaiscript/language/chaiscript_eval.hpp

@@ -448,19 +448,22 @@ namespace chaiscript
           Boxed_Value rhs = this->children[1]->eval(t_ss); 
           Boxed_Value lhs = this->children[0]->eval(t_ss);
 
+          if (lhs.is_return_value()) {
+            throw exception::eval_error("Error, cannot assign to temporary value.");
+          } else if (lhs.is_const()) {
+            throw exception::eval_error("Error, cannot assign to constant value.");
+          }
+
+
           if (m_oper != Operators::Opers::invalid && lhs.get_type_info().is_arithmetic() &&
               rhs.get_type_info().is_arithmetic())
           {
             try {
               return Boxed_Number::do_oper(m_oper, lhs, rhs);
             } catch (const std::exception &) {
-              throw exception::eval_error("Error with unsupported arithmetic assignment operation");
+              throw exception::eval_error("Error with unsupported arithmetic assignment operation.");
             }
           } else if (m_oper == Operators::Opers::assign) {
-            if (lhs.is_return_value()) {
-              throw exception::eval_error("Error, cannot assign to temporary value.");
-            }
-
             try {
 
               if (lhs.is_undef()) {
@@ -1141,10 +1144,10 @@ namespace chaiscript
 
         Boxed_Value eval_internal(const chaiscript::detail::Dispatch_State &t_ss) const override{
           if (!this->children.empty()) {
-            throw detail::Return_Value(this->children[0]->eval(t_ss));
+            throw detail::Return_Value{this->children[0]->eval(t_ss)};
           }
           else {
-            throw detail::Return_Value(void_var());
+            throw detail::Return_Value{void_var()};
           }
         }
     };
@@ -1201,6 +1204,10 @@ namespace chaiscript
             // short circuit arithmetic operations
             if (m_oper != Operators::Opers::invalid && m_oper != Operators::Opers::bitwise_and && bv.get_type_info().is_arithmetic())
             {
+              if ((m_oper == Operators::Opers::pre_increment || m_oper == Operators::Opers::pre_decrement) && bv.is_const())
+              {
+                throw exception::eval_error("Error with prefix operator evaluation: cannot modify constant value.");
+              }
               return Boxed_Number::do_oper(m_oper, bv);
             } else {
               chaiscript::eval::detail::Function_Push_Pop fpp(t_ss);

include/chaiscript/language/chaiscript_optimizer.hpp

@@ -356,7 +356,7 @@ namespace chaiscript {
 
             const auto make_constant = [&node, &fun_name](auto val){
               const auto match = fun_name + "(" + node->children[1]->children[0]->text + ")";
-              return chaiscript::make_unique<eval::AST_Node_Impl<T>, eval::Constant_AST_Node<T>>(std::move(match), node->location, Boxed_Value(val));
+              return chaiscript::make_unique<eval::AST_Node_Impl<T>, eval::Constant_AST_Node<T>>(std::move(match), node->location, const_var(val));
             };
 
             if (fun_name == "double") {

src/main.cpp

@@ -164,15 +164,15 @@ void help(int n) {
   }
 }
 
-bool throws_exception(const std::function<void ()> &f)
+std::string throws_exception(const std::function<void ()> &f)
 {
   try {
     f();
-  } catch (...) {
+  } catch (const std::exception &e) {
-    return true;
+    return e.what();
   }
 
-  return false;
+  return "";
 }
 
 chaiscript::exception::eval_error get_eval_error(const std::function<void ()> &f)

unittests/3.x/assign_const.chai

@@ -1,2 +1,2 @@
-assert_throws("Mismatched types in equation, lhs is const.", fun() { 1 = 2 } );
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { 1 = 2 } );
-assert_throws("Mismatched types in equation, lhs is const.", fun() { 1 + 2 = 2 } );
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { 1 + 2 = 2 } );

unittests/3.x/function_introspection.chai

@@ -66,10 +66,10 @@ var group = group_guard.get_contained_functions();
 assert_equal(true, group[0].has_guard())
 assert_equal(false, group[1].has_guard())
 
-assert_throws("Function does not have a guard", fun() { group[0].get_guard(); } );
+assert_throws("Function does not have a guard", fun[group]() { group[1].get_guard(); } );
-assert_throws("Function does not have a guard", fun() { without_guard.get_guard(); } );
+assert_throws("Function does not have a guard", fun[without_guard]() { without_guard.get_guard(); } );
 
 var guard = with_guard.get_guard();
 
 assert_equal(false, guard.has_guard());
-assert_throws("Function does not have a guard", fun() { guard.get_guard(); } );
+assert_throws("Function does not have a guard", fun[guard]() { guard.get_guard(); } );

unittests/3.x/invalid_function_assignment.chai

@@ -1 +1 @@
-assert_throws("Illegal const function assignment", fun() { clone = `-` } );
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { clone = `-` } );

unittests/3.x/invalid_function_reassignment.chai

@@ -1 +1,2 @@
-assert_throws("Invalid function reassignment", fun() { var x = 5; x = `-`; } );
+assert_throws("Error: \"Unable to find appropriate'=' operator.\" With parameters: (int, const Function)", fun() { auto x = 5; x = `-`; } );
+

unittests/3.x/malformed_inline_map.chai

@@ -1,2 +1,8 @@
 
-assert_throws("Parse failure", fun() { eval("[\"hello\":5,\"j\",\"k\"]") } );
+try {
+   eval("[\"hello\":5,\"j\",\"k\"]");
+   assert_true(false);
+} catch (eval_error ee) {
+}
+
+

unittests/3.x/operators_float.chai

@@ -13,4 +13,4 @@ assert_equal(0, i -= i)
 assert_equal(3, j *= 1.5)
 assert_equal(1.5, j /= 2)
 assert_equal(2.5, j += 1)
-assert_throws("No modulus for float", fun() { k % 2 } );
+assert_throws("Error: \"Error with numeric operator calling: %\"", fun[k]() { k % 2 } );

unittests/assign_const.chai

@@ -1,2 +1,2 @@
-assert_throws("Mismatched types in equation, lhs is const.", fun() { 1 = 2 } );
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { 1 = 2 } );
-assert_throws("Mismatched types in equation, lhs is const.", fun() { 1 + 2 = 2 } );
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { 1 + 2 = 2 } );

unittests/dynamic_object_dynamic_attrs_explicit.chai

@@ -10,5 +10,7 @@ var o = MyClass();
 
 assert_true(o.is_explicit());
 
-assert_throws("error", fun[o](){o.x = 2})
+assert_throws("Error: \"'x' is not a function.\"", fun[o](){o.x = 2})
+
+
 

unittests/function_introspection.chai

@@ -66,10 +66,10 @@ auto group = group_guard.get_contained_functions();
 assert_equal(true, group[0].has_guard())
 assert_equal(false, group[1].has_guard())
 
-assert_throws("Function does not have a guard", fun() { group[0].get_guard(); } );
+assert_throws("Function does not have a guard", fun[group]() { group[1].get_guard(); } );
-assert_throws("Function does not have a guard", fun() { without_guard.get_guard(); } );
+assert_throws("Function does not have a guard", fun[without_guard]() { without_guard.get_guard(); } );
 
 auto guard = with_guard.get_guard();
 
 assert_equal(false, guard.has_guard());
-assert_throws("Function does not have a guard", fun() { guard.get_guard(); } );
+assert_throws("Function does not have a guard", fun[guard]() { guard.get_guard(); } );

unittests/function_redefinition.chai

@@ -1,2 +1,2 @@
-assert_throws("Function already defined", fun(){ def foo(x) { x + 1 }; def foo(x) { x + 1 } } );
+assert_throws("Error: \"Function redefined 'foo'\"", fun(){ def foo(x) { x + 1 }; def foo(x) { x + 1 } } );
 

unittests/invalid_function_assignment.chai

@@ -1 +1 @@
-assert_throws("Illegal const function assignment", fun() { clone = `-` } );
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { clone = `-` } );

unittests/invalid_function_reassignment.chai

@@ -1 +1,4 @@
-assert_throws("Invalid function reassignment", fun() { auto x = 5; x = `-`; } );
+assert_throws("Error: \"Unable to find appropriate'=' operator.\" With parameters: (int, const Function)", fun() { auto x = 5; x = `-`; } );
+
+
+

unittests/malformed_inline_map.chai

@@ -1,2 +1,8 @@
 
-assert_throws("Parse failure", fun() { eval("[\"hello\":5,\"j\",\"k\"]") } );
+try {
+ eval("[\"hello\":5,\"j\",\"k\"]");
+ assert_true(false);
+} catch (eval_error ee) {
+}
+
+

unittests/operators_float.chai

@@ -13,4 +13,6 @@ assert_equal(0, i -= i)
 assert_equal(3, j *= 1.5)
 assert_equal(1.5, j /= 2)
 assert_equal(2.5, j += 1)
-assert_throws("No modulus for float", fun() { k % 2 } );
+assert_throws("Error: \"Error with numeric operator calling: %\"", fun[k]() { k % 2 } );
+
+

unittests/operators_int.chai

@@ -29,3 +29,13 @@ assert_equal(2, j += 1);
 assert_equal(1, --j);
 assert_equal(2, ++j);
 
+
+assert_throws("Error: \"Error with prefix operator evaluation: cannot modify constant value.\"", fun() { ++4; });
+assert_throws("Error: \"Error with prefix operator evaluation: cannot modify constant value.\"", fun() { --4; });
+
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { 5 = 5; });
+assert_throws("Error: \"Error, cannot assign to constant value.\"", fun() { int(5) = 5; });
+
+
+
+

unittests/return_value_assignment.chai

@@ -6,6 +6,20 @@ try {
   print("Caught Error: " + e.what());
 }
 
+def get_value()
+{
+  var i = 5;
+  return i;
+}
+
+def get_value_2()
+{
+  return 5;
+}
+
+// TODO these should be fixed somehow
+//assert_throws("Cannot assign to temporary", fun[](){ get_value() = 3; });
+//assert_throws("Cannot assign to temporary", fun[](){ get_value_2() = 3; });
 
 
 try {

unittests/string_unicode_unicode.chai

@@ -8,8 +8,8 @@ assert_equal("Test\u2022Me", "Test•Me")
 assert_equal("\xF0\x9F\x8D\x8C", "🍌")
 assert_equal("\U0001F34C", "🍌")
 
-assert_throws("Invalid 16 bit universal character", fun(){ parse("\"\\uD83C\""); });
+assert_throws("Error: \"Invalid 16 bit universal character\"", fun(){ parse("\"\\uD83C\""); });
-assert_throws("Incomplete unicode escape sequence", fun(){ parse("\"\\uD83 \""); });
+assert_throws("Error: \"Incomplete unicode escape sequence\"", fun(){ parse("\"\\uD83 \""); });
 
 assert_equal("\U00024B62", "𤭢")
 

unittests/unit_test.inc

@@ -42,12 +42,14 @@ def assert_not_equal(x, y)
 
 def assert_throws(desc, x)
 {
-  if (throws_exception(x))
+  auto result = trim(throws_exception(x));
+  if (result == desc)
   {
     // Passes
   } else {
     // Fails
-    print("assert_throws failure, function did not throw exception: " + to_string(desc));
+    print("assert_throws failed: got '${result}' expected '${desc}'");
     exit(-1);
   }
 }
+

unittests/variable_redefinition.chai

@@ -1,2 +1,2 @@
-assert_throws("Variable already defined", fun() { auto y = 10; auto y = 20; })
+assert_throws("Error: \"Variable redefined 'y'\"", fun() { auto y = 10; auto y = 20; })