My rule of thumb is: if it is the type of error that I want a stacktrace for: use an exception. For example: programming errors, unhandled cases etc. If it is

My rule of thumb is: if it is the type of error that I want a stacktrace for: use an exception. For example: programming errors, unhandled cases etc. If it is an error that I want to handle explicitly, for example by showing a nice user message: use a result type. It is okay to use combinators in this case, but use them wisely.