lacona-stateful

This library works with the lacona parser.

Typically, the parser works much like a typical node stream, emitting 3 events: data, end, and error. Each parse is completely independent of all other parses.

However, for GUIs, it may be useful to keep track of state between parses, to correctly interpret keystrokes or handle animations, and more.

This module implements this stateful behavior.

Usage

var lacona = require('lacona'),
	parser = new lacona.Parser(),
	stateful = require('lacona-stateful');

stateful(parser);

This makes use of events-intercept, hijacking the standard events and calling the following instead:

• insert is called when a new OutputOption is available
• update is called when a previously inserted OutputOption should be replaced
• delete is called when a previously inserted OutputOption should be removed

insert and update are passed a Number id and an OutputOption representing the new option.

delete is just passed the Number id.

If an error happened at any point, error will be emitted and passed an Error. If this happens, the state will be reset and all events for the next parse will be inserts.

Automatic mode is useful for interactive parsing sessions. Because inserts, updates, and deletes are provided independently, order can be maintained between requests and interfaces can be managed properly.

Development

While a separate package, lacona-stateful is a fundamental component of the lacona framework, and will be supported in the same way.