/usr/share/perl5/JavaScript/Minifier.pm is in libjavascript-minifier-perl 1.05-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 | package JavaScript::Minifier;
use strict;
use warnings;
require Exporter;
our @ISA = qw(Exporter);
our @EXPORT_OK = qw(minify);
our $VERSION = '1.05';
# -----------------------------------------------------------------------------
#return true if the character is allowed in identifier.
sub isAlphanum {
my $x = shift;
return ($x =~ /[\w\$\\]/ || ord($x) > 126);
}
sub isSpace {
my $x = shift;
return ($x eq ' ' || $x eq "\t");
}
sub isEndspace {
my $x = shift;
return ($x eq "\n" || $x eq "\r" || $x eq "\f");
}
sub isWhitespace {
my $x = shift;
return (isSpace($x) || isEndspace($x));
}
# New line characters before or after these characters can be removed.
# Not + - / in this list because they require special care.
sub isInfix {
my $x = shift;
$x =~ /[,;:=&%*<>\?\|\n]/;
}
# New line characters after these characters can be removed.
sub isPrefix {
my $x = shift;
return ($x =~ /[\{\(\[!]/ || isInfix($x));
}
# New line characters before these characters can removed.
sub isPostfix {
my $x = shift;
return ($x =~ /[\}\)\]]/ || isInfix($x));
}
# -----------------------------------------------------------------------------
sub _get {
my $s = shift;
if ($s->{inputType} eq 'file') {
return getc($s->{input});
}
elsif ($s->{inputType} eq 'string') {
if ($s->{'inputPos'} < length($s->{input})) {
return substr($s->{input}, $s->{inputPos}++, 1);
}
else { # Simulate getc() when off the end of the input string.
return undef;
}
}
else {
die "no input";
}
}
sub _put {
my $s = shift;
my $x = shift;
my $outfile = ($s->{outfile});
if (defined($s->{outfile})) {
print $outfile $x;
}
else {
$s->{output} .= $x;
}
}
# -----------------------------------------------------------------------------
# print a
# move b to a
# move c to b
# move d to c
# new d
#
# i.e. print a and advance
sub action1 {
my $s = shift;
if (!isWhitespace($s->{a})) {
$s->{lastnws} = $s->{a};
}
$s->{last} = $s->{a};
action2($s);
}
# sneeky output $s->{a} for comments
sub action2 {
my $s = shift;
_put($s, $s->{a});
action3($s);
}
# move b to a
# move c to b
# move d to c
# new d
#
# i.e. delete a
sub action3 {
my $s = shift;
$s->{a} = $s->{b};
action4($s);
}
# move c to b
# move d to c
# new d
#
# i.e. delete b
sub action4 {
my $s = shift;
$s->{b} = $s->{c};
$s->{c} = $s->{d};
$s->{d} = _get($s);
}
# -----------------------------------------------------------------------------
# put string and regexp literals
# when this sub is called, $s->{a} is on the opening delimiter character
sub putLiteral {
my $s = shift;
my $delimiter = $s->{a}; # ', " or /
action1($s);
do {
while (defined($s->{a}) && $s->{a} eq '\\') { # escape character only escapes only the next one character
action1($s);
action1($s);
}
action1($s);
} until ($s->{last} eq $delimiter || !defined($s->{a}));
if ($s->{last} ne $delimiter) { # ran off end of file before printing the closing delimiter
die 'unterminated ' . ($delimiter eq '\'' ? 'single quoted string' : $delimiter eq '"' ? 'double quoted string' : 'regular expression') . ' literal, stopped';
}
}
# -----------------------------------------------------------------------------
# If $s->{a} is a whitespace then collapse all following whitespace.
# If any of the whitespace is a new line then ensure $s->{a} is a new line
# when this function ends.
sub collapseWhitespace {
my $s = shift;
while (defined($s->{a}) && isWhitespace($s->{a}) &&
defined($s->{b}) && isWhitespace($s->{b})) {
if (isEndspace($s->{a}) || isEndspace($s->{b})) {
$s->{a} = "\n";
}
action4($s); # delete b
}
}
# Advance $s->{a} to non-whitespace or end of file.
# Doesn't print any of this whitespace.
sub skipWhitespace {
my $s = shift;
while (defined($s->{a}) && isWhitespace($s->{a})) {
action3($s);
}
}
# Advance $s->{a} to non-whitespace or end of file
# If any of the whitespace is a new line then print one new line.
sub preserveEndspace {
my $s = shift;
collapseWhitespace($s);
if (defined($s->{a}) && isEndspace($s->{a}) && defined($s->{b}) && !isPostfix($s->{b}) ) {
action1($s);
}
skipWhitespace($s);
}
sub onWhitespaceConditionalComment {
my $s = shift;
return (defined($s->{a}) && isWhitespace($s->{a}) &&
defined($s->{b}) && $s->{b} eq '/' &&
defined($s->{c}) && ($s->{c} eq '/' || $s->{c} eq '*') &&
defined($s->{d}) && $s->{d} eq '@');
}
# -----------------------------------------------------------------------------
sub minify {
my %h = @_;
# Immediately turn hash into a hash reference so that notation is the same in this function
# as others. Easier refactoring.
my $s = \%h; # hash reference for "state". This module is functional programming and the state is passed between functions.
# determine if the the input is a string or a file handle.
my $ref = \$s->{input};
if (defined($ref) && ref($ref) eq 'SCALAR'){
$s->{inputPos} = 0;
$s->{inputType} = 'string';
}
else {
$s->{inputType} = 'file';
}
# Determine if the output is to a string or a file.
if (!defined($s->{outfile})) {
$s->{output} = '';
}
# Print the copyright notice first
if ($s->{copyright}) {
_put($s, '/* ' . $s->{copyright} . ' */');
}
# Initialize the buffer.
do {
$s->{a} = _get($s);
} while (defined($s->{a}) && isWhitespace($s->{a}));
$s->{b} = _get($s);
$s->{c} = _get($s);
$s->{d} = _get($s);
$s->{last} = undef; # assign for safety
$s->{lastnws} = undef; # assign for safety
# local variables
my $ccFlag; # marks if a comment is an Internet Explorer conditional comment and should be printed to output
while (defined($s->{a})) { # on this line $s->{a} should always be a non-whitespace character or undef (i.e. end of file)
if (isWhitespace($s->{a})) { # check that this program is running correctly
die 'minifier bug: minify while loop starting with whitespace, stopped';
}
# Each branch handles trailing whitespace and ensures $s->{a} is on non-whitespace or undef when branch finishes
if ($s->{a} eq '/') { # a division, comment, or regexp literal
if (defined($s->{b}) && $s->{b} eq '/') { # slash-slash comment
$ccFlag = defined($s->{c}) && $s->{c} eq '@'; # tests in IE7 show no space allowed between slashes and at symbol
do {
$ccFlag ? action2($s) : action3($s);
} until (!defined($s->{a}) || isEndspace($s->{a}));
if (defined($s->{a})) { # $s->{a} is a new line
if ($ccFlag) {
action1($s); # cannot use preserveEndspace($s) here because it might not print the new line
skipWhitespace($s);
}
elsif (defined($s->{last}) && !isEndspace($s->{last}) && !isPrefix($s->{last})) {
preserveEndspace($s);
}
else {
skipWhitespace($s);
}
}
}
elsif (defined($s->{b}) && $s->{b} eq '*') { # slash-star comment
$ccFlag = defined($s->{c}) && $s->{c} eq '@'; # test in IE7 shows no space allowed between star and at symbol
do {
$ccFlag ? action2($s) : action3($s);
} until (!defined($s->{b}) || ($s->{a} eq '*' && $s->{b} eq '/'));
if (defined($s->{b})) { # $s->{a} is asterisk and $s->{b} is foreslash
if ($ccFlag) {
action2($s); # the *
action2($s); # the /
# inside the conditional comment there may be a missing terminal semi-colon
preserveEndspace($s);
}
else { # the comment is being removed
action3($s); # the *
$s->{a} = ' '; # the /
collapseWhitespace($s);
if (defined($s->{last}) && defined($s->{b}) &&
((isAlphanum($s->{last}) && (isAlphanum($s->{b})||$s->{b} eq '.')) ||
($s->{last} eq '+' && $s->{b} eq '+') || ($s->{last} eq '-' && $s->{b} eq '-'))) { # for a situation like 5-/**/-2 or a/**/a
# When entering this block $s->{a} is whitespace.
# The comment represented whitespace that cannot be removed. Therefore replace the now gone comment with a whitespace.
action1($s);
}
elsif (defined($s->{last}) && !isPrefix($s->{last})) {
preserveEndspace($s);
}
else {
skipWhitespace($s);
}
}
}
else {
die 'unterminated comment, stopped';
}
}
elsif (defined($s->{lastnws}) && ($s->{lastnws} eq ')' || $s->{lastnws} eq ']' ||
$s->{lastnws} eq '.' || isAlphanum($s->{lastnws}))) { # division
action1($s);
collapseWhitespace($s);
# don't want a division to become a slash-slash comment with following conditional comment
onWhitespaceConditionalComment($s) ? action1($s) : preserveEndspace($s);
}
else { # regexp literal
putLiteral($s);
collapseWhitespace($s);
# don't want closing delimiter to become a slash-slash comment with following conditional comment
onWhitespaceConditionalComment($s) ? action1($s) : preserveEndspace($s);
}
}
elsif ($s->{a} eq '\'' || $s->{a} eq '"' ) { # string literal
putLiteral($s);
preserveEndspace($s);
}
elsif ($s->{a} eq '+' || $s->{a} eq '-') { # careful with + + and - -
action1($s);
collapseWhitespace($s);
if (defined($s->{a}) && isWhitespace($s->{a})) {
(defined($s->{b}) && $s->{b} eq $s->{last}) ? action1($s) : preserveEndspace($s);
}
}
elsif (isAlphanum($s->{a})) { # keyword, identifiers, numbers
action1($s);
collapseWhitespace($s);
if (defined($s->{a}) && isWhitespace($s->{a})) {
# if $s->{b} is '.' could be (12 .toString()) which is property invocation. If space removed becomes decimal point and error.
(defined($s->{b}) && (isAlphanum($s->{b}) || $s->{b} eq '.')) ? action1($s) : preserveEndspace($s);
}
}
elsif ($s->{a} eq ']' || $s->{a} eq '}' || $s->{a} eq ')') { # no need to be followed by space but maybe needs following new line
action1($s);
preserveEndspace($s);
}
elsif ($s->{stripDebug} && $s->{a} eq ';' &&
defined($s->{b}) && $s->{b} eq ';' &&
defined($s->{c}) && $s->{c} eq ';') {
action3($s); # delete one of the semi-colons
$s->{a} = '/'; # replace the other two semi-colons
$s->{b} = '/'; # so the remainder of line is removed
}
else { # anything else just prints and trailing whitespace discarded
action1($s);
skipWhitespace($s);
}
}
if (!defined($s->{outfile})) {
return $s->{output};
}
} # minify()
# -----------------------------------------------------------------------------
1;
__END__
=head1 NAME
JavaScript::Minifier - Perl extension for minifying JavaScript code
=head1 SYNOPSIS
To minify a JavaScript file and have the output written directly to another file
use JavaScript::Minifier qw(minify);
open(INFILE, 'myScript.js') or die;
open(OUTFILE, '>myScript-min.js') or die;
minify(input => *INFILE, outfile => *OUTFILE);
close(INFILE);
close(OUTFILE);
To minify a JavaScript string literal. Note that by omitting the outfile parameter a the minified code is returned as a string.
my minifiedJavaScript = minify(input => 'var x = 2;');
To include a copyright comment at the top of the minified code.
minify(input => 'var x = 2;', copyright => 'BSD License');
To treat ';;;' as '//' so that debugging code can be removed. This is a common JavaScript convention for minification.
minify(input => 'var x = 2;', stripDebug => 1);
The "input" parameter is manditory. The "output", "copyright", and "stripDebug" parameters are optional and can be used in any combination.
=head1 DESCRIPTION
This module removes unnecessary whitespace from JavaScript code. The primary requirement developing this module is to not break working code: if working JavaScript is in input then working JavaScript is output. It is ok if the input has missing semi-colons, snips like '++ +' or '12 .toString()', for example. Internet Explorer conditional comments are copied to the output but the code inside these comments will not be minified.
The ECMAScript specifications allow for many different whitespace characters: space, horizontal tab, vertical tab, new line, carriage return, form feed, and paragraph separator. This module understands all of these as whitespace except for vertical tab and paragraph separator. These two types of whitespace are not minimized.
For static JavaScript files, it is recommended that you minify during the build stage of web deployment. If you minify on-the-fly then it might be a good idea to cache the minified file. Minifying static files on-the-fly repeatedly is wasteful.
=head2 EXPORT
None by default.
Exportable on demand: minifiy()
=head1 SEE ALSO
This project is developed using an SVN repository. To check out the repository
svn co http://dev.michaux.ca/svn/random/JavaScript-Minifier
This module is inspired by Douglas Crockford's JSMin:
http://www.crockford.com/javascript/jsmin.html
You may also be interested in the CSS::Minifier module also available on CPAN.
=head1 AUTHORS
Peter Michaux, E<lt>petermichaux@gmail.comE<gt>
Eric Herrera, E<lt>herrera@10east.comE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2007 by Peter Michaux
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.6 or,
at your option, any later version of Perl 5 you may have available.
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