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Synopsis

This module is basically a class that provides basics mechanisms for parsing strings. It works with my tokenizer although it can be used pretty much with anything emitting tokens the same way. The parser work with a queue of functions. For each token the next function in the queue is called.

write you own parser

tokenizer

Only one thing is required for the parser to work. This thing is a tokenizer these concepts are very different and that is why they are implemented separately. The easiest solution is to use my tokenizer

parser

The default behaviour upon receiving a new token is ignoring it. It prints a warning when reaching EOF with the number of tokens that have been ignored. However this is probably not what you want to do!

In order to parse what you need to parse you have to provide the parser with the functions which will be called for each token. Let's call these function handlers. This can be achieved through configuration of the basic parser or through inheritance.

var Parser = require('parser');
var util = require('util');
var MyTokenizer = require('./MyTokenizer');

function MyParser() {
    // MyTokenizer is the tokenizer we configured
    // but it's not the subject of this module
    Parser.apply(this, new MyTokenizer());

    // override the default behaviour
    this.defaultHandler(this.default);

    // specify the function that will be called on the first token
    this.initialHander(this.initial);
}
util.inherits(MyParser, Parser);

/**
 * Of course you will have to define these function somewhere
 */

this is very theorical but you can have a look at what is in the example folder

Handlers

Handlers are just javascript functions accepting the following arguments

  • token the actual token which emitted by the tokenizer
  • type the type of this token (i.e. 'number', 'whitespace', 'word')
  • next a function to specify what needs to be called on the next token(s)

returning true from a handler causes the same token to be reemitted to the next handler.

project

TODOs

  • more robustness / better error handling
  • features requests
  • Support for asynchronous handlers

Features requests / bugs

If you'd like the parser to do something that it doesn't do or want to report a bug please use the github issue tracker on github

fork / patches / pull requests

You are very welcome to send patches or pull requests