This module demonstrates that we can easily generate contextual error message thanks to the introspection API. Indeed, when a parsing error occurs, there exist items in the stack whose analysis is not completed. Therefore, the non terminals of their productions are probably the syntactically classes that are being recognized when the error occurred.
val pop_until :
(Parser.MenhirInterpreter.element -> 'a list) ->
'b Parser.MenhirInterpreter.env ->
'a listval keep_predictions :
Parser.MenhirInterpreter.xsymbol list ->
(Parser.MenhirInterpreter.production * int) ->
Parser.MenhirInterpreter.xsymbol listval element_contains_prediction_items :
Parser.MenhirInterpreter.element ->
Parser.MenhirInterpreter.xsymbol listval find_context :
'a Parser.MenhirInterpreter.checkpoint ->
Parser.MenhirInterpreter.xsymbol listval parse_error : Position.t -> string -> (unit -> 'a) -> 'aval contextual_error_msg :
PureLexer.Lexer.t ->
'a Parser.MenhirInterpreter.checkpoint ->
(unit -> 'b) ->
'b