Module: JSMin

Defined in:
lib/jsmin.rb

Overview

JSMin

Ruby implementation of Douglas Crockford’s JavaScript minifier, JSMin.

Author

Ryan Grove ([email protected])

Version

1.0.1 (2008-11-10)

Copyright

Copyright © 2008 Ryan Grove. All rights reserved.

Website

github.com/rgrove/jsmin/

Example

require 'rubygems'
require 'jsmin'

File.open('example.js', 'r') {|file| puts JSMin.minify(file) }

Constant Summary collapse

CHR_APOS = 
"'".freeze
CHR_ASTERISK = 
'*'.freeze
CHR_BACKSLASH = 
'\\'.freeze
CHR_CR = 
"\r".freeze
CHR_FRONTSLASH = 
'/'.freeze
CHR_LF = 
"\n".freeze
CHR_QUOTE = 
'"'.freeze
CHR_SPACE = 
' '.freeze
ORD_LF = 
"\n"[0].freeze
ORD_SPACE = 
' '[0].freeze
ORD_TILDE = 
'~'[0].freeze

Class Method Summary collapse

Class Method Details

.minify(input) ⇒ Object

Reads JavaScript from input (which can be a String or an IO object) and returns a String containing minified JS.



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# File 'lib/jsmin.rb', line 72

def minify(input)
  @js = StringScanner.new(input.is_a?(IO) ? input.read : input.to_s)

  @a         = "\n"
  @b         = nil
  @lookahead = nil
  @output    = ''

  action_get

  while !@a.nil? do
    case @a
    when CHR_SPACE
      if alphanum?(@b)
        action_output
      else
        action_copy
      end

    when CHR_LF
      if @b == CHR_SPACE
        action_get
      elsif @b =~ /[{\[\(+-]/
        action_output
      else
        if alphanum?(@b)
          action_output
        else
          action_copy
        end
      end

    else
      if @b == CHR_SPACE
        if alphanum?(@a)
          action_output
        else
          action_get
        end
      elsif @b == CHR_LF
        if @a =~ /[}\]\)\\"+-]/
          action_output
        else
          if alphanum?(@a)
            action_output
          else
            action_get
          end
        end
      else
        action_output
      end
    end
  end

  @output
end