rJSmin - A Javascript Minifier For Python

TABLE OF CONTENTS

1. Introduction
2. Copyright and License
3. System Requirements
4. Installation
5. Documentation
6. Bugs
7. Author Information

INTRODUCTION

rJSmin is a javascript minifier written in python.

The minifier is based on the semantics of jsmin.c by Douglas Crockford.

The module is a re-implementation aiming for speed, so it can be used at runtime (rather than during a preprocessing step). Usually it produces the same results as the original jsmin.c. It differs in the following ways:

• there is no error detection: unterminated string, regex and comment literals are treated as regular javascript code and minified as such.
• Control characters inside string and regex literals are left untouched; they are not converted to spaces (nor to \n)
• Newline characters are not allowed inside string and regex literals, except for line continuations in string literals (ECMA-5).
• "return /regex/" is recognized correctly.
• "+ +" and "- -" sequences are not collapsed to '++' or '--'
• Newlines before ! operators are removed more sensibly
• Comments starting with an exclamation mark (!) can be kept optionally
• rJSmin does not handle streams, but only complete strings. (However, the module provides a "streamy" interface).

Since most parts of the logic are handled by the regex engine it's way faster than the original python port of jsmin.c by Baruch Even. The speed factor varies between about 6 and 55 depending on input and python version (it gets faster the more compressed the input already is). Compared to the speed-refactored python port by Dave St.Germain the performance gain is less dramatic but still between 3 and 50 (for huge inputs). See the docs/BENCHMARKS file for details.

rjsmin.c is a reimplementation of rjsmin.py in C and speeds it up even more.

COPYRIGHT AND LICENSE

Copyright 2011 - 2014 André Malo or his licensors, as applicable.

The whole package (except for the files in the bench/ directory) is distributed under the Apache License Version 2.0. You'll find a copy in the root directory of the distribution or online at: <http://www.apache.org/licenses/LICENSE-2.0>.

SYSTEM REQUIREMENTS

Both python 2 (>=2.4) and python 3 are supported.

INSTALLATION

Using pip

$ pip install rjsmin

Using distutils

$ python setup.py install

The following extra options to the install command may be of interest:

--without-c-extensions Don't install C extensions --without-docs Do not install documentation files

Drop-in

rJSmin effectively consists of two files: rjsmin.py and rjsmin.c, the latter being entirely optional. So, for simple integration you can just copy rjsmin.py into your project and use it.

DOCUMENTATION

A generated API documentation is available in the docs/apidoc/ directory. But you can just look into the module. It provides a simple function, called jsmin which takes the script as a string and returns the minified script as a string.

The module additionally provides a "streamy" interface similar to the one jsmin.c provides:

$ python -mrjsmin <script >minified

It takes two options:

-b Keep bang-comments (Comments starting with an exclamation mark) -p Force using the python implementation (not the C implementation)

The latest documentation is also available online at <http://opensource.perlig.de/rjsmin/>.

BUGS

No bugs, of course. ;-) But if you've found one or have an idea how to improve rjsmin, feel free to send a pull request on github or send a mail to <rjsmin-bugs@perlig.de>.

AUTHOR INFORMATION

André "nd" Malo <nd@perlig.de> GPG: 0x8103A37E

If God intended people to be naked, they would be born that way.

-- Oscar Wilde