tools/jsmin.rb

   1 #!/usr/bin/ruby
   2 # jsmin.rb 2007-07-20
   3 # Author: Uladzislau Latynski
   4 # This work is a translation from C to Ruby of jsmin.c published by
   5 # Douglas Crockford.  Permission is hereby granted to use the Ruby
   6 # version under the same conditions as the jsmin.c on which it is
   7 # based.
   8 #
   9 # /* jsmin.c
  10 #    2003-04-21
  11 #
  12 # Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
  13 #
  14 # Permission is hereby granted, free of charge, to any person obtaining a copy of
  15 # this software and associated documentation files (the "Software"), to deal in
  16 # the Software without restriction, including without limitation the rights to
  17 # use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  18 # of the Software, and to permit persons to whom the Software is furnished to do
  19 # so, subject to the following conditions:
  20 #
  21 # The above copyright notice and this permission notice shall be included in all
  22 # copies or substantial portions of the Software.
  23 #
  24 # The Software shall be used for Good, not Evil.
  25 #
  26 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  27 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  28 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  29 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  30 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  31 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32 # SOFTWARE.
  33
  34 EOF = -1
  35 $theA = ""
  36 $theB = ""
  37
  38 # isAlphanum -- return true if the character is a letter, digit, underscore,
  39 # dollar sign, or non-ASCII character
  40 def isAlphanum(c)
  41    return false if !c || c == EOF
  42    return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
  43            (c >= 'A' && c <= 'Z') || c == '_' || c == '$' ||
  44            c == '\\' || c[0] > 126)
  45 end
  46
  47 # get -- return the next character from stdin. Watch out for lookahead. If
  48 # the character is a control character, translate it to a space or linefeed.
  49 def get()
  50   c = $stdin.getc
  51   return EOF if(!c)
  52   c = c.chr
  53   return c if (c >= " " || c == "\n" || c.unpack("c") == EOF)
  54   return "\n" if (c == "\r")
  55   return " "
  56 end
  57
  58 # Get the next character without getting it.
  59 def peek()
  60     lookaheadChar = $stdin.getc
  61     $stdin.ungetc(lookaheadChar)
  62     return lookaheadChar.chr
  63 end
  64
  65 # mynext -- get the next character, excluding comments.
  66 # peek() is used to see if a '/' is followed by a '/' or '*'.
  67 def mynext()
  68     c = get
  69     # saute les commentaires (également les lignes commencant pas ;;)
  70
  71     if (c == ";" and peek == ";")
  72       while(true)
  73           c = get
  74           if (c[0] <= "\n"[0])
  75             return c
  76           end
  77       end
  78     end
  79     if (c == "/")
  80        prochain = peek
  81         if(prochain  == "/")
  82             while(true)
  83                 c = get
  84                 if (c[0] <= "\n"[0])
  85                   return c
  86                 end
  87             end
  88         end
  89         if(peek == "*")
  90             get
  91             while(true)
  92                 case get
  93                 when "*"
  94                    if (peek == "/")
  95                         get
  96                         return " "
  97                     end
  98                 when EOF
  99                     raise "Unterminated comment"
 100                 end
 101             end
 102         end
 103     end
 104     return c
 105 end
 106
 107
 108 # action -- do something! What you do is determined by the argument: 1
 109 # Output A. Copy B to A. Get the next B. 2 Copy B to A. Get the next B.
 110 # (Delete A). 3 Get the next B. (Delete B). action treats a string as a
 111 # single character. Wow! action recognizes a regular expression if it is
 112 # preceded by ( or , or =.
 113 def action(a)
 114     if(a==1)
 115         $stdout.write $theA
 116     end
 117     if(a==1 || a==2)
 118         $theA = $theB
 119         if ($theA == "\'" || $theA == "\"")
 120             while (true)
 121                 $stdout.write $theA
 122                 $theA = get
 123                 break if ($theA == $theB)
 124                 raise "Unterminated string literal" if ($theA <= "\n")
 125                 if ($theA == "\\")
 126                     $stdout.write $theA
 127                     $theA = get
 128                 end
 129             end
 130         end
 131     end
 132     if(a==1 || a==2 || a==3)
 133         $theB = mynext
 134         if ($theB == "/" && ($theA == "(" || $theA == "," || $theA == "=" ||
 135                              $theA == ":" || $theA == "[" || $theA == "!" ||
 136                              $theA == "&" || $theA == "|" || $theA == "?" ||
 137                              $theA == "{" || $theA == "}" || $theA == ";" ||
 138                              $theA == "\n"))
 139             $stdout.write $theA
 140             $stdout.write $theB
 141             while (true)
 142                 $theA = get
 143                 if ($theA == "/")
 144                     break
 145                 elsif ($theA == "\\")
 146                     $stdout.write $theA
 147                     $theA = get
 148                 elsif ($theA <= "\n")
 149                     raise "Unterminated RegExp Literal"
 150                 end
 151                 $stdout.write $theA
 152             end
 153             $theB = mynext
 154         end
 155     end
 156 end
 157
 158 # jsmin -- Copy the input to the output, deleting the characters which are
 159 # insignificant to JavaScript. Comments will be removed. Tabs will be
 160 # replaced with spaces. Carriage returns will be replaced with linefeeds.
 161 # Most spaces and linefeeds will be removed.
 162 def jsmin
 163     $theA = "\n"
 164     action(3)
 165     while ($theA != EOF)
 166         case $theA
 167         when " "
 168             if (isAlphanum($theB))
 169                 action(1)
 170             else
 171                 action(2)
 172             end
 173         when "\n"
 174             case ($theB)
 175             when "{","[","(","+","-"
 176                 action(1)
 177             when " "
 178                 action(3)
 179             else
 180                 if (isAlphanum($theB))
 181                     action(1)
 182                 else
 183                     action(2)
 184                 end
 185             end
 186         else
 187             case ($theB)
 188             when " "
 189                 if (isAlphanum($theA))
 190                     action(1)
 191                 else
 192                     action(3)
 193                 end
 194             when "\n"
 195                 case ($theA)
 196                 when "}","]",")","+","-","\"","\\", "'", '"'
 197                     action(1)
 198                 else
 199                     if (isAlphanum($theA))
 200                         action(1)
 201                     else
 202                         action(3)
 203                     end
 204                 end
 205             else
 206                 action(1)
 207             end
 208         end
 209     end
 210 end
 211
 212 ARGV.each do |anArg|
 213     $stdout.write "// #{anArg}\n"
 214 end
 215
 216 jsmin