tools/jsmin.js

   1 /* jsmin.js - 2006-08-31
   2 Author: Franck Marcia
   3 This work is an adaptation of jsminc.c published by Douglas Crockford.
   4 Permission is hereby granted to use the Javascript version under the same
   5 conditions as the jsmin.c on which it is based.
   6
   7 jsmin.c
   8 2006-05-04
   9
  10 Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
  11
  12 Permission is hereby granted, free of charge, to any person obtaining a copy of
  13 this software and associated documentation files (the "Software"), to deal in
  14 the Software without restriction, including without limitation the rights to
  15 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  16 of the Software, and to permit persons to whom the Software is furnished to do
  17 so, subject to the following conditions:
  18
  19 The above copyright notice and this permission notice shall be included in all
  20 copies or substantial portions of the Software.
  21
  22 The Software shall be used for Good, not Evil.
  23
  24 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  25 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  26 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  27 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  28 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  29 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30 SOFTWARE.
  31
  32 Update:
  33         add level:
  34                 1: minimal, keep linefeeds if single
  35                 2: normal, the standard algorithm
  36                 3: agressive, remove any linefeed and doesn't take care of potential
  37                    missing semicolons (can be regressive)
  38         store stats
  39                 jsmin.oldSize
  40                 jsmin.newSize
  41 */
  42
  43 String.prototype.has = function(c) {
  44         return this.indexOf(c) > -1;
  45 };
  46
  47 function jsmin(comment, input, level) {
  48
  49         if (input === undefined) {
  50                 input = comment;
  51                 comment = '';
  52                 level = 2;
  53         } else if (level === undefined || level < 1 || level > 3) {
  54                 level = 2;
  55         }
  56
  57         if (comment.length > 0) {
  58                 comment += '\n';
  59         }
  60
  61         var a = '',
  62                 b = '',
  63                 EOF = -1,
  64                 LETTERS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz',
  65                 DIGITS = '0123456789',
  66                 ALNUM = LETTERS + DIGITS + '_$\\',
  67                 theLookahead = EOF;
  68
  69
  70         /* isAlphanum -- return true if the character is a letter, digit, underscore,
  71                         dollar sign, or non-ASCII character.
  72         */
  73
  74         function isAlphanum(c) {
  75                 return c != EOF && (ALNUM.has(c) || c.charCodeAt(0) > 126);
  76         }
  77
  78
  79         /* get -- return the next character. Watch out for lookahead. If the
  80                         character is a control character, translate it to a space or
  81                         linefeed.
  82         */
  83
  84         function get() {
  85
  86                 var c = theLookahead;
  87                 if (get.i == get.l) {
  88                         return EOF;
  89                 }
  90                 theLookahead = EOF;
  91                 if (c == EOF) {
  92                         c = input.charAt(get.i);
  93                         ++get.i;
  94                 }
  95                 if (c >= ' ' || c == '\n') {
  96                         return c;
  97                 }
  98                 if (c == '\r') {
  99                         return '\n';
 100                 }
 101                 return ' ';
 102         }
 103
 104         get.i = 0;
 105         get.l = input.length;
 106
 107
 108         /* peek -- get the next character without getting it.
 109         */
 110
 111         function peek() {
 112                 theLookahead = get();
 113                 return theLookahead;
 114         }
 115
 116
 117         /* next -- get the next character, excluding comments. peek() is used to see
 118                         if a '/' is followed by a '/' or '*'.
 119         */
 120
 121         function next() {
 122
 123                 var c = get();
 124                 if (c == '/') {
 125                         switch (peek()) {
 126                         case '/':
 127                                 for (;;) {
 128                                         c = get();
 129                                         if (c <= '\n') {
 130                                                 return c;
 131                                         }
 132                                 }
 133                                 break;
 134                         case '*':
 135                                 get();
 136                                 for (;;) {
 137                                         switch (get()) {
 138                                         case '*':
 139                                                 if (peek() == '/') {
 140                                                         get();
 141                                                         return ' ';
 142                                                 }
 143                                                 break;
 144                                         case EOF:
 145                                                 throw 'Error: Unterminated comment.';
 146                                         }
 147                                 }
 148                                 break;
 149                         default:
 150                                 return c;
 151                         }
 152                 }
 153                 return c;
 154         }
 155
 156
 157         /* action -- do something! What you do is determined by the argument:
 158                         1   Output A. Copy B to A. Get the next B.
 159                         2   Copy B to A. Get the next B. (Delete A).
 160                         3   Get the next B. (Delete B).
 161            action treats a string as a single character. Wow!
 162            action recognizes a regular expression if it is preceded by ( or , or =.
 163         */
 164
 165         function action(d) {
 166
 167                 var r = [];
 168
 169                 if (d == 1) {
 170                         r.push(a);
 171                 }
 172
 173                 if (d < 3) {
 174                         a = b;
 175                         if (a == '\'' || a == '"') {
 176                                 for (;;) {
 177                                         r.push(a);
 178                                         a = get();
 179                                         if (a == b) {
 180                                                 break;
 181                                         }
 182                                         if (a <= '\n') {
 183                                                 throw 'Error: unterminated string literal: ' + a;
 184                                         }
 185                                         if (a == '\\') {
 186                                                 r.push(a);
 187                                                 a = get();
 188                                         }
 189                                 }
 190                         }
 191                 }
 192
 193                 b = next();
 194
 195                 if (b == '/' && '(,=:[!&|'.has(a)) {
 196                         r.push(a);
 197                         r.push(b);
 198                         for (;;) {
 199                                 a = get();
 200                                 if (a == '/') {
 201                                         break;
 202                                 } else if (a =='\\') {
 203                                         r.push(a);
 204                                         a = get();
 205                                 } else if (a <= '\n') {
 206                                         throw 'Error: unterminated Regular Expression literal';
 207                                 }
 208                                 r.push(a);
 209                         }
 210                         b = next();
 211                 }
 212
 213                 return r.join('');
 214         }
 215
 216
 217         /* m -- Copy the input to the output, deleting the characters which are
 218                         insignificant to JavaScript. Comments will be removed. Tabs will be
 219                         replaced with spaces. Carriage returns will be replaced with
 220                         linefeeds.
 221                         Most spaces and linefeeds will be removed.
 222         */
 223
 224         function m() {
 225
 226                 var r = [];
 227                 a = '\n';
 228
 229                 r.push(action(3));
 230
 231                 while (a != EOF) {
 232                         switch (a) {
 233                         case ' ':
 234                                 if (isAlphanum(b)) {
 235                                         r.push(action(1));
 236                                 } else {
 237                                         r.push(action(2));
 238                                 }
 239                                 break;
 240                         case '\n':
 241                                 switch (b) {
 242                                 case '{':
 243                                 case '[':
 244                                 case '(':
 245                                 case '+':
 246                                 case '-':
 247                                         r.push(action(1));
 248                                         break;
 249                                 case ' ':
 250                                         r.push(action(3));
 251                                         break;
 252                                 default:
 253                                         if (isAlphanum(b)) {
 254                                                 r.push(action(1));
 255                                         } else {
 256                                                 if (level == 1 && b != '\n') {
 257                                                         r.push(action(1));
 258                                                 } else {
 259                                                         r.push(action(2));
 260                                                 }
 261                                         }
 262                                 }
 263                                 break;
 264                         default:
 265                                 switch (b) {
 266                                 case ' ':
 267                                         if (isAlphanum(a)) {
 268                                                 r.push(action(1));
 269                                                 break;
 270                                         }
 271                                         r.push(action(3));
 272                                         break;
 273                                 case '\n':
 274                                         if (level == 1 && a != '\n') {
 275                                                 r.push(action(1));
 276                                         } else {
 277                                                 switch (a) {
 278                                                 case '}':
 279                                                 case ']':
 280                                                 case ')':
 281                                                 case '+':
 282                                                 case '-':
 283                                                 case '"':
 284                                                 case '\'':
 285                                                         if (level == 3) {
 286                                                                 r.push(action(3));
 287                                                         } else {
 288                                                                 r.push(action(1));
 289                                                         }
 290                                                         break;
 291                                                 default:
 292                                                         if (isAlphanum(a)) {
 293                                                                 r.push(action(1));
 294                                                         } else {
 295                                                                 r.push(action(3));
 296                                                         }
 297                                                 }
 298                                         }
 299                                         break;
 300                                 default:
 301                                         r.push(action(1));
 302                                         break;
 303                                 }
 304                         }
 305                 }
 306
 307                 return r.join('');
 308         }
 309
 310         jsmin.oldSize = input.length;
 311         ret = m(input);
 312         jsmin.newSize = ret.length;
 313
 314         return comment + ret;
 315
 316 }
 317
 318 (function (a) {
 319     if (!a[0]) {
 320         print("Usage: jsmin.js file.js");
 321         quit(1);
 322     }
 323     var input = readFile(a[0]);
 324     if (!input) {
 325         print("jslint: Couldn't open file '" + a[0] + "'.");
 326         quit(1);
 327     }
 328    print(jsmin(input));
 329 })(arguments);