failReply
failReply(ctx: Context, errors?: ErrorList, index?: number): Reply
Creates a reply object representing an unsuccessful parse.
This function creates a Result object with a status of Status.Fail out of the provided errors list ([] by default), and it uses the supplied context (modifying its index if the index parameter is present) to create a new context for the reply.
This function should always be used to create a failing reply, since it will always create both a new context and result, ensuring that older contexts aren't accidentally overwritten.
Parameters
ctx: The context for the newly created reply.errors: The error list detailing errors that hapopened at the context's location. Defaults to an empty array.index: The index into the context's input. This is used just to change that index if necessary (in backtracking, for example). Defaults to the context's current index.
Returns
- Returns a reply object with the given context and result value.