1 /*
2 *
3 * JSMin.java 2006-02-13
4 *
5 * Updated 2007-08-20 with updates from jsmin.c (2007-05-22)
6 *
7 * Copyright (c) 2006 John Reilly (www.inconspicuous.org)
8 *
9 * This work is a translation from C to Java of jsmin.c published by
10 * Douglas Crockford. Permission is hereby granted to use the Java
11 * version under the same conditions as the jsmin.c on which it is
12 * based.
13 *
14 *
15 *
16 *
17 * jsmin.c 2003-04-21
18 *
19 * Copyright (c) 2002 Douglas Crockford (www.crockford.com)
20 *
21 * Permission is hereby granted, free of charge, to any person obtaining a copy
22 * of this software and associated documentation files (the "Software"), to deal
23 * in the Software without restriction, including without limitation the rights
24 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
25 * copies of the Software, and to permit persons to whom the Software is
26 * furnished to do so, subject to the following conditions:
27 *
28 * The above copyright notice and this permission notice shall be included in
29 * all copies or substantial portions of the Software.
30 *
31 * The Software shall be used for Good, not Evil.
32 *
33 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
34 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
35 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
36 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
37 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
38 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
39 * SOFTWARE.
40 */
41
42 package org.inconspicuous.jsmin;
43
44 import java.io.FileInputStream;
45 import java.io.FileNotFoundException;
46 import java.io.IOException;
47 import java.io.InputStream;
48 import java.io.OutputStream;
49 import java.io.PushbackInputStream;
50
51
52 public class JSMin {
53 private static final int EOF = -1;
54
55 private PushbackInputStream in;
56 private OutputStream out;
57
58 private int theA;
59 private int theB;
60
61 public JSMin(InputStream in, OutputStream out) {
62 this.in = new PushbackInputStream(in);
63 this.out = out;
64 }
65
66 /**
67 * isAlphanum -- return true if the character is a letter, digit,
68 * underscore, dollar sign, or non-ASCII character.
69 */
70 static boolean isAlphanum(int c) {
71 return ( (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
72 (c >= 'A' && c <= 'Z') || c == '_' || c == '$' || c == '\\' ||
73 c > 126);
74 }
75
76 /**
77 * get -- return the next character from stdin. Watch out for lookahead. If
78 * the character is a control character, translate it to a space or
79 * linefeed.
80 */
81 int get() throws IOException {
82 int c = in.read();
83
84 if (c >= ' ' || c == '\n' || c == EOF) {
85 return c;
86 }
87
88 if (c == '\r') {
89 return '\n';
90 }
91
92 return ' ';
93 }
94
95
96
97 /**
98 * Get the next character without getting it.
99 */
100 int peek() throws IOException {
101 int lookaheadChar = in.read();
102 in.unread(lookaheadChar);
103 return lookaheadChar;
104 }
105
106 /**
107 * next -- get the next character, excluding comments. peek() is used to see
108 * if a '/' is followed by a '/' or '*'.
109 */
110 int next() throws IOException, UnterminatedCommentException {
111 int c = get();
112 if (c == '/') {
113 switch (peek()) {
114 case '/':
115 for (;;) {
116 c = get();
117 if (c <= '\n') {
118 return c;
119 }
120 }
121
122 case '*':
123 get();
124 for (;;) {
125 switch (get()) {
126 case '*':
127 if (peek() == '/') {
128 get();
129 return ' ';
130 }
131 break;
132 case EOF:
133 throw new UnterminatedCommentException();
134 }
135 }
136
137 default:
138 return c;
139 }
140
141 }
142 return c;
143 }
144
145 /**
146 * action -- do something! What you do is determined by the argument: 1
147 * Output A. Copy B to A. Get the next B. 2 Copy B to A. Get the next B.
148 * (Delete A). 3 Get the next B. (Delete B). action treats a string as a
149 * single character. Wow! action recognizes a regular expression if it is
150 * preceded by ( or , or =.
151 */
152
153 void action(int d) throws IOException, UnterminatedRegExpLiteralException,
154 UnterminatedCommentException, UnterminatedStringLiteralException {
155 switch (d) {
156 case 1:
157 out.write(theA);
158 case 2:
159 theA = theB;
160
161 if (theA == '\'' || theA == '"') {
162 for (;;) {
163 out.write(theA);
164 theA = get();
165 if (theA == theB) {
166 break;
167 }
168 if (theA <= '\n') {
169 throw new UnterminatedStringLiteralException();
170 }
171 if (theA == '\\') {
172 out.write(theA);
173 theA = get();
174 }
175 }
176 }
177
178 case 3:
179 theB = next();
180 if (theB == '/' && (theA == '(' || theA == ',' || theA == '=' ||
181 theA == ':' || theA == '[' || theA == '!' ||
182 theA == '&' || theA == '|' || theA == '?' ||
183 theA == '{' || theA == '}' || theA == ';' ||
184 theA == '\n')) {
185 out.write(theA);
186 out.write(theB);
187 for (;;) {
188 theA = get();
189 if (theA == '/') {
190 break;
191 } else if (theA == '\\') {
192 out.write(theA);
193 theA = get();
194 } else if (theA <= '\n') {
195 throw new UnterminatedRegExpLiteralException();
196 }
197 out.write(theA);
198 }
199 theB = next();
200 }
201 }
202 }
203
204 /**
205 * jsmin -- Copy the input to the output, deleting the characters which are
206 * insignificant to JavaScript. Comments will be removed. Tabs will be
207 * replaced with spaces. Carriage returns will be replaced with linefeeds.
208 * Most spaces and linefeeds will be removed.
209 */
210 public void jsmin() throws IOException, UnterminatedRegExpLiteralException, UnterminatedCommentException, UnterminatedStringLiteralException{
211 theA = '\n';
212 action(3);
213 while (theA != EOF) {
214 switch (theA) {
215 case ' ':
216 if (isAlphanum(theB)) {
217 action(1);
218 } else {
219 action(2);
220 }
221 break;
222 case '\n':
223 switch (theB) {
224 case '{':
225 case '[':
226 case '(':
227 case '+':
228 case '-':
229 action(1);
230 break;
231 case ' ':
232 action(3);
233 break;
234 default:
235 if (isAlphanum(theB)) {
236 action(1);
237 } else {
238 action(2);
239 }
240 }
241 break;
242 default:
243 switch (theB) {
244 case ' ':
245 if (isAlphanum(theA)) {
246 action(1);
247 break;
248 }
249 action(3);
250 break;
251 case '\n':
252 switch (theA) {
253 case '}':
254 case ']':
255 case ')':
256 case '+':
257 case '-':
258 case '"':
259 case '\'':
260 action(1);
261 break;
262 default:
263 if (isAlphanum(theA)) {
264 action(1);
265 } else {
266 action(3);
267 }
268 }
269 break;
270 default:
271 action(1);
272 break;
273 }
274 }
275 }
276 out.flush();
277 }
278
279 class UnterminatedCommentException extends Exception {
280 }
281
282 class UnterminatedStringLiteralException extends Exception {
283 }
284
285 class UnterminatedRegExpLiteralException extends Exception {
286 }
287
288 public static void main(String arg[]) {
289 try {
290 JSMin jsmin = new JSMin(new FileInputStream(arg[0]), System.out);
291 jsmin.jsmin();
292 } catch (FileNotFoundException e) {
293 e.printStackTrace();
294 } catch (ArrayIndexOutOfBoundsException e) {
295 e.printStackTrace();
296 } catch (IOException e) {
297 e.printStackTrace();
298 } catch (UnterminatedRegExpLiteralException e) {
299 e.printStackTrace();
300 } catch (UnterminatedCommentException e) {
301 e.printStackTrace();
302 } catch (UnterminatedStringLiteralException e) {
303 e.printStackTrace();
304 }
305 }
306
307
308 }