Implemented WarningCapacitor as a counterpart to ErrorCapacitor

* in difference to ErrorCapacitor this class doesn't throw an exception on "discharge" but returns the gathered warnings
* adapted FunctionTransform and frontend error handling to include warnings
* added static "try_create" method to TransformationFacade
** wraps construction error handling
** custom logic may be embedded using the std::function argument
*** this was implemented to prevent unneccessary code duplication for handling both construction and generation errors
* adapted FunctionTransform to return warning as "warning" nodes in the result tree
** added functional lambda expression factory method "handleErrors"
*** returns a error handling lambda expression for a given ResultNodeFacade
* implemented WarningGuard class in frontend executable
** guarantees warnings to be printed to std::cerr independent of any exceptions

1 files changed, 3 insertions, 5 deletions

diff --git a/src/support/error/error_capacitor.h b/src/support/error/error_capacitor.h
index 6017cb4..1c225e9 100644
--- a/src/support/error/error_capacitor.h
+++ b/src/support/error/error_capacitor.h
@@ -7,7 +7,7 @@
 
 namespace InputXSLT {
 
-class ErrorCapacitor : public ErrorMultiplexer::Receiver {
+class ErrorCapacitor : public ErrorMultiplexer::receiver {
 	public:
 		class exception;
 
@@ -15,17 +15,15 @@ class ErrorCapacitor : public ErrorMultiplexer::Receiver {
 		typedef std::unique_ptr<error_cache> error_cache_ptr;
 
 		ErrorCapacitor(ErrorMultiplexer*);
-		~ErrorCapacitor();
 
 		void discharge();
 
 		virtual void receive(
-			const ErrorMultiplexer::ErrorType,
+			const ErrorMultiplexer::error_type,
 			const std::string&
 		);
 
 	private:
-		ErrorMultiplexer* const multiplexer_;
 		error_cache_ptr error_cache_;
 
 };
@@ -34,7 +32,7 @@ class ErrorCapacitor::exception {
 	public:
 		exception(error_cache_ptr);
 
-		const error_cache* getCachedErrors() const;
+		const error_cache& operator*() const;
 
 	private:
 		error_cache_ptr error_cache_;