UtilEvalError is an error corresponding to an EvalError but thrown by a utility or other class that does not have the caller context (Node) available to it. A normal EvalError must supply the caller Node in order for error messages to be pinned to the correct line and location in the script. UtilEvalError is a checked exception that is *not* a subtype of EvalError, but instead must be caught and rethrown as an EvalError by the a nearest location with context. The method toEvalError( Node ) should be used to throw the EvalError, supplying the node.

To summarize: Utilities throw UtilEvalError. ASTs throw EvalError. ASTs catch UtilEvalError and rethrow it as EvalError using toEvalError( Node ).

Philosophically, EvalError and UtilEvalError corrospond to RuntimeException. However they are constrained in this way in order to add the context for error reporting.