eventually
Attempt the zero-argument continuation. The implementation is free to execute it now or to put it in a bag of continuations to run later in an arbitrary order. There may be performance and/or scale benefits to processing entries in FIFO, LIFO, or some hybrid order, but the correctness is not affected by a choice of order. The implementation may run the expression in parallel with the invoking thread and other such expressions.
Parameters
lexing
The LexingState for which to report problems.
continuation
What to do at some point in the future.