NAME

       CSS::Minifier::XS - XS based CSS minifier

SYNOPSIS

         use CSS::Minifier::XS qw(minify);
         $minified = minify($css);

DESCRIPTION

       "CSS::Minifier::XS" is a CSS "minifier"; its designed to remove un-necessary whitespace
       and comments from CSS files, while also not breaking the CSS.

       "CSS::Minifier::XS" is similar in function to "CSS::Minifier", but is substantially faster
       as its written in XS and not just pure Perl.

METHODS

       minify($css)
           Minifies the given $css, returning the minified CSS back to the caller.

HOW IT WORKS

       "CSS::Minifier::XS" minifies the CSS by removing un-necessary whitespace from CSS
       documents.  Comment blocks are also removed, except when (a) they contain the word
       "copyright" in them, or (b) they're needed to implement the "Mac/IE Comment Hack".

       Internally, the minification is done by taking multiple passes through the CSS document:

   Pass 1: Tokenize
       First, we go through and parse the CSS document into a series of tokens internally.  The
       tokenizing process does not check to make sure that you've got syntactically valid CSS, it
       just breaks up the text into a stream of tokens suitable for processing by the subsequent
       stages.

   Pass 2: Collapse
       We then march through the token list and collapse certain tokens down to their smallest
       possible representation.  If they're still included in the final results we only want to
       include them at their shortest.

       Whitespace
           Runs of multiple whitespace characters are reduced down to a single whitespace
           character.  If the whitespace contains any "end of line" (EOL) characters, then the
           end result is the first EOL character encountered.  Otherwise, the result is the first
           whitespace character in the run.

       Comments
           Comments implementing the "Mac/IE Comment Hack" are collapsed down to the smallest
           possible comment that would still implement the hack ("/*\*/" to start the hack, and
           "/**/" to end it).

       Zero Units
           Zero Units (e.g. "0px") are reduced down to just "0", as the CSS specification
           indicates that the unit is not required when its a zero value.

   Pass 3: Pruning
       We then go back through the token list and prune and remove un-necessary tokens.

       Whitespace
           Wherever possible, whitespace is removed; before+after comment blocks, and
           before+after various symbols/sigils.

       Comments
           Comments that either (a) are needed to implement the "Mac/IE Comment Hack", or that
           (b) contain the word "copyright" in them are preserved.  All other comments are
           removed.

       Symbols/Sigils
           Semi-colons that are immediately followed by a closing brace (e.g. ";}") are removed;
           semi-colons are needed to separate multiple declarations, but aren't required at the
           end of a group.

       Everything else
           We keep everything else; identifiers, quoted literal strings, symbols/sigils, etc.

   Pass 4: Re-assembly
       Lastly, we go back through the token list and re-assemble it all back into a single CSS
       string, which is then returned back to the caller.

AUTHOR

       Graham TerMarsch (cpan@howlingfrog.com)

REPORTING BUGS

       Please report bugs via RT
       (<http://rt.cpan.org/Dist/Display.html?Queue=CSS::Minifier::XS>), and be sure to include
       the CSS that you're having troubles minifying.

COPYRIGHT

       Copyright (C) 2007-, Graham TerMarsch.  All Rights Reserved.

       This is free software; you can redistribute it and/or modify it under the same license as
       Perl itself.

SEE ALSO

       "CSS::Minifier".