consumer

Consumer

This module provides basic state management and functions for reading Javascipt strings character-by-character and/or with RegExps.

Install

npm install consumer

API

var Consumer = require('consumer');

var c = new Consumer("1234567890");
var match = c.consume(/\d/);
console.log(match);
// ["1"]

match = c.advance(1).consume(/(\d)(\d)/);
console.log(match);
// ["34","3","4"]

console.log(c.current);
// 5
console.log(c.position);
// 4

Consumer(source[, start]);

Constructs a new Consumer object.

current

Gets the character at the current index.

position

Gets or sets the current position.

source

Returns the source string.

done

Returns true when the position is at the end.

consume(regexp)

Executes the regexp against the source at the current position. If the match fails, null is returned and the position is not changed.

Note 1: This module fiddles with the RegExp's lastIndex property to do the continuation matches. For it to work, all RegExp objects used will be re-compiled with the g flag if it doesn't have one. This is a slight performance hit- so should define them with the g flag to avoid it.

Note 2: Since continuation matching is used, the ^ (start of input) anchor should not be used. consume() forces ALL matches start at the current position. To skip over something, advance the position by:

• manually setting the position property.
• calling advance(n).
• or, consume() and discared the result.

peek(n)

Peeks at the next n characters of the source without advancing the position.

advance(n)

Advance the position ahead n characters.

License

The MIT License (MIT)

Copyright (c) 2013 William Kapke

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.