moo


Moo!
====

Moo is a highly-optimised tokenizer/lexer generator. Use it to tokenize your strings, before parsing 'em with a parser like nearley or whatever else you're into.

* Fast
* Convenient
* uses Regular Expressions
* tracks Line Numbers
* handles Keywords
* supports States
* custom Errors
* is even Iterable
* has no dependencies
* 4KB minified + gzipped
* Moo!

Is it fast?
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Yup! Flying-cows-and-singed-steak fast.

Moo is the fastest JS tokenizer around. It's ~2–10x faster than most other tokenizers; it's a couple orders of magnitude faster than some of the slower ones.

Define your tokens using regular expressions. Moo will compile 'em down to a single RegExp for performance. It uses the new ES6 sticky flag where possible to make things faster; otherwise it falls back to an almost-as-efficient workaround. (For more than you ever wanted to know about this, read adventures in the land of substrings and RegExps.)

You _might_ be able to go faster still by writing your lexer by hand rather than using RegExps, but that's icky.

Oh, and it avoids parsing RegExps by itself. Because that would be horrible.

Usage
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First, you need to do the needful: $ npm install moo, or whatever will ship this code to your computer. Alternatively, grab the moo.js file by itself and slap it into your web page via a