Earley cannot handle epsilon-states already contained in chart
问题 I have implemented the Earley parser using a queue to process states. The queue is seeded with the top-level rule. For each state in the queue, one of the operations (prediction, scanning, completion) is performed by adding new states to the queue. Duplicate states are not added. The problem I am having is best described with the following grammar: When parsing A , the following happens: As you can tell, A will not be fully resolved . This is because the completion with the epsilon state will