Compact JS resource better by using rjsmin.

Source/devtools/scripts/rjsmin.py

-#!/usr/bin/env python
-# -*- coding: ascii -*-
-#
-# Copyright 2011 - 2013
-# Andr\xe9 Malo or his licensors, as applicable
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-r"""
-=====================
- Javascript Minifier
-=====================
-
-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
-- 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 1.2 and 7. See the docs/BENCHMARKS file for
-details.
-
-rjsmin.c is a reimplementation of rjsmin.py in C and speeds it up even more.
-
-Both python 2 and python 3 are supported.
-
-.. _jsmin.c by Douglas Crockford:
-   http://www.crockford.com/javascript/jsmin.c
-"""
-__author__ = "Andr\xe9 Malo"
-__author__ = getattr(__author__, 'decode', lambda x: __author__)('latin-1')
-__docformat__ = "restructuredtext en"
-__license__ = "Apache License, Version 2.0"
-__version__ = '1.0.7'
-__all__ = ['jsmin']
-
-import re as _re
-
-
-def _make_jsmin(python_only=False):
-    """
-    Generate JS minifier based on `jsmin.c by Douglas Crockford`_
-
-    .. _jsmin.c by Douglas Crockford:
-       http://www.crockford.com/javascript/jsmin.c
-
-    :Parameters:
-      `python_only` : ``bool``
-        Use only the python variant. If true, the c extension is not even
-        tried to be loaded.
-
-    :Return: Minifier
-    :Rtype: ``callable``
-    """
-    # pylint: disable = R0912, R0914, W0612
-    if not python_only:
-        try:
-            import _rjsmin
-        except ImportError:
-            pass
-        else:
-            return _rjsmin.jsmin
-    try:
-        xrange
-    except NameError:
-        xrange = range # pylint: disable = W0622
-
-    space_chars = r'[\000-\011\013\014\016-\040]'
-
-    line_comment = r'(?://[^\r\n]*)'
-    space_comment = r'(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)'
-    string1 = \
-        r'(?:\047[^\047\\\r\n]*(?:\\(?:[^\r\n]|\r?\n|\r)[^\047\\\r\n]*)*\047)'
-    string2 = r'(?:"[^"\\\r\n]*(?:\\(?:[^\r\n]|\r?\n|\r)[^"\\\r\n]*)*")'
-    strings = r'(?:%s|%s)' % (string1, string2)
-
-    charclass = r'(?:\[[^\\\]\r\n]*(?:\\[^\r\n][^\\\]\r\n]*)*\])'
-    nospecial = r'[^/\\\[\r\n]'
-    regex = r'(?:/(?![\r\n/*])%s*(?:(?:\\[^\r\n]|%s)%s*)*/)' % (
-        nospecial, charclass, nospecial
-    )
-    space = r'(?:%s|%s)' % (space_chars, space_comment)
-    newline = r'(?:%s?[\r\n])' % line_comment
-
-    def fix_charclass(result):
-        """ Fixup string of chars to fit into a regex char class """
-        pos = result.find('-')
-        if pos >= 0:
-            result = r'%s%s-' % (result[:pos], result[pos + 1:])
-
-        def sequentize(string):
-            """
-            Notate consecutive characters as sequence
-
-            (1-4 instead of 1234)
-            """
-            first, last, result = None, None, []
-            for char in map(ord, string):
-                if last is None:
-                    first = last = char
-                elif last + 1 == char:
-                    last = char
-                else:
-                    result.append((first, last))
-                    first = last = char
-            if last is not None:
-                result.append((first, last))
-            return ''.join(['%s%s%s' % (
-                chr(first),
-                last > first + 1 and '-' or '',
-                last != first and chr(last) or ''
-            ) for first, last in result])
-
-        return _re.sub(r'([\000-\040\047])', # for better portability
-            lambda m: '\\%03o' % ord(m.group(1)), (sequentize(result)
-                .replace('\\', '\\\\')
-                .replace('[', '\\[')
-                .replace(']', '\\]')
-            )
-        )
-
-    def id_literal_(what):
-        """ Make id_literal like char class """
-        match = _re.compile(what).match
-        result = ''.join([
-            chr(c) for c in xrange(127) if not match(chr(c))
-        ])
-        return '[^%s]' % fix_charclass(result)
-
-    def not_id_literal_(keep):
-        """ Make negated id_literal like char class """
-        match = _re.compile(id_literal_(keep)).match
-        result = ''.join([
-            chr(c) for c in xrange(127) if not match(chr(c))
-        ])
-        return r'[%s]' % fix_charclass(result)
-
-    not_id_literal = not_id_literal_(r'[a-zA-Z0-9_$]')
-    preregex1 = r'[(,=:\[!&|?{};\r\n]'
-    preregex2 = r'%(not_id_literal)sreturn' % locals()
-
-    id_literal = id_literal_(r'[a-zA-Z0-9_$]')
-    id_literal_open = id_literal_(r'[a-zA-Z0-9_${\[(!+-]')
-    id_literal_close = id_literal_(r'[a-zA-Z0-9_$}\])"\047+-]')
-
-    dull = r'[^\047"/\000-\040]'
-
-    space_sub = _re.compile((
-        r'(%(dull)s+)'
-        r'|(%(strings)s%(dull)s*)'
-        r'|(?<=%(preregex1)s)'
-            r'%(space)s*(?:%(newline)s%(space)s*)*'
-            r'(%(regex)s%(dull)s*)'
-        r'|(?<=%(preregex2)s)'
-            r'%(space)s*(?:%(newline)s%(space)s)*'
-            r'(%(regex)s%(dull)s*)'
-        r'|(?<=%(id_literal_close)s)'
-            r'%(space)s*(?:(%(newline)s)%(space)s*)+'
-            r'(?=%(id_literal_open)s)'
-        r'|(?<=%(id_literal)s)(%(space)s)+(?=%(id_literal)s)'
-        r'|(?<=\+)(%(space)s)+(?=\+)'
-        r'|(?<=-)(%(space)s)+(?=-)'
-        r'|%(space)s+'
-        r'|(?:%(newline)s%(space)s*)+'
-    ) % locals()).sub
-    #print space_sub.__self__.pattern
-
-    def space_subber(match):
-        """ Substitution callback """
-        # pylint: disable = C0321, R0911
-        groups = match.groups()
-        if groups[0]: return groups[0]
-        elif groups[1]: return groups[1]
-        elif groups[2]: return groups[2]
-        elif groups[3]: return groups[3]
-        elif groups[4]: return '\n'
-        elif groups[5] or groups[6] or groups[7]: return ' '
-        else: return ''
-
-    def jsmin(script): # pylint: disable = W0621
-        r"""
-        Minify javascript based on `jsmin.c by Douglas Crockford`_\.
-
-        Instead of parsing the stream char by char, it uses a regular
-        expression approach which minifies the whole script with one big
-        substitution regex.
-
-        .. _jsmin.c by Douglas Crockford:
-           http://www.crockford.com/javascript/jsmin.c
-
-        :Parameters:
-          `script` : ``str``
-            Script to minify
-
-        :Return: Minified script
-        :Rtype: ``str``
-        """
-        return space_sub(space_subber, '\n%s\n' % script).strip()
-
-    return jsmin
-
-jsmin = _make_jsmin()
-
-
-def jsmin_for_posers(script):
-    r"""
-    Minify javascript based on `jsmin.c by Douglas Crockford`_\.
-
-    Instead of parsing the stream char by char, it uses a regular
-    expression approach which minifies the whole script with one big
-    substitution regex.
-
-    .. _jsmin.c by Douglas Crockford:
-       http://www.crockford.com/javascript/jsmin.c
-
-    :Warning: This function is the digest of a _make_jsmin() call. It just
-              utilizes the resulting regex. It's just for fun here and may
-              vanish any time. Use the `jsmin` function instead.
-
-    :Parameters:
-      `script` : ``str``
-        Script to minify
-
-    :Return: Minified script
-    :Rtype: ``str``
-    """
-    def subber(match):
-        """ Substitution callback """
-        groups = match.groups()
-        return (
-            groups[0] or
-            groups[1] or
-            groups[2] or
-            groups[3] or
-            (groups[4] and '\n') or
-            (groups[5] and ' ') or
-            (groups[6] and ' ') or
-            (groups[7] and ' ') or
-            ''
-        )
-
-    return _re.sub(
-        r'([^\047"/\000-\040]+)|((?:(?:\047[^\047\\\r\n]*(?:\\(?:[^\r\n]|\r?'
-        r'\n|\r)[^\047\\\r\n]*)*\047)|(?:"[^"\\\r\n]*(?:\\(?:[^\r\n]|\r?\n|'
-        r'\r)[^"\\\r\n]*)*"))[^\047"/\000-\040]*)|(?<=[(,=:\[!&|?{};\r\n])(?'
-        r':[\000-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/))*'
-        r'(?:(?:(?://[^\r\n]*)?[\r\n])(?:[\000-\011\013\014\016-\040]|(?:/\*'
-        r'[^*]*\*+(?:[^/*][^*]*\*+)*/))*)*((?:/(?![\r\n/*])[^/\\\[\r\n]*(?:('
-        r'?:\\[^\r\n]|(?:\[[^\\\]\r\n]*(?:\\[^\r\n][^\\\]\r\n]*)*\]))[^/\\\['
-        r'\r\n]*)*/)[^\047"/\000-\040]*)|(?<=[\000-#%-,./:-@\[-^`{-~-]return'
-        r')(?:[\000-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/'
-        r'))*(?:(?:(?://[^\r\n]*)?[\r\n])(?:[\000-\011\013\014\016-\040]|(?:'
-        r'/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)))*((?:/(?![\r\n/*])[^/\\\[\r\n]*(?'
-        r':(?:\\[^\r\n]|(?:\[[^\\\]\r\n]*(?:\\[^\r\n][^\\\]\r\n]*)*\]))[^/'
-        r'\\\[\r\n]*)*/)[^\047"/\000-\040]*)|(?<=[^\000-!#%&(*,./:-@\[\\^`{|'
-        r'~])(?:[\000-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)'
-        r'*/))*(?:((?:(?://[^\r\n]*)?[\r\n]))(?:[\000-\011\013\014\016-\040]'
-        r'|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/))*)+(?=[^\000-\040"#%-\047)*,./'
-        r':-@\\-^`|-~])|(?<=[^\000-#%-,./:-@\[-^`{-~-])((?:[\000-\011\013\01'
-        r'4\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)))+(?=[^\000-#%-,./:'
-        r'-@\[-^`{-~-])|(?<=\+)((?:[\000-\011\013\014\016-\040]|(?:/\*[^*]*'
-        r'\*+(?:[^/*][^*]*\*+)*/)))+(?=\+)|(?<=-)((?:[\000-\011\013\014\016-'
-        r'\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/)))+(?=-)|(?:[\000-\011\013'
-        r'\014\016-\040]|(?:/\*[^*]*\*+(?:[^/*][^*]*\*+)*/))+|(?:(?:(?://[^'
-        r'\r\n]*)?[\r\n])(?:[\000-\011\013\014\016-\040]|(?:/\*[^*]*\*+(?:[^'
-        r'/*][^*]*\*+)*/))*)+', subber, '\n%s\n' % script
-    ).strip()
-
-
-if __name__ == '__main__':
-    import sys as _sys
-    _sys.stdout.write(jsmin(_sys.stdin.read()))