Custom error tokens

Error recovery can be handled using built-in error token. If necessary user can also define own custom error tokens which enable:

• executing custom code when recovery begins and ends
• executing custom code for each input symbol skipped during recovery
• setting lookahead handling options

Error tokens are declared with command:

Custom error tokens behave the same as built-in error token. When error occurs, parser searches stack for first state that has any error-handling actions defined. Both built-in error token as well as user-defined custom tokens can be matched during this search. If a state has actions for multiple error tokens, the one declared earlier in grammar will be chosen.