Further minify non-visible JavaScript.

tools/jsmin.py

+#!/usr/bin/python
+
+# This code is original from jsmin by Douglas Crockford, it was translated to
+# Python by Baruch Even. The original code had the following copyright and
+# license.
+#
+# /* jsmin.c
+#    2007-05-22
+#
+# Copyright (c) 2002 Douglas Crockford  (www.crockford.com)
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy of
+# this software and associated documentation files (the "Software"), to deal in
+# the Software without restriction, including without limitation the rights to
+# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+# of the Software, and to permit persons to whom the Software is furnished to do
+# so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# The Software shall be used for Good, not Evil.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# */
+
+from StringIO import StringIO
+
+def jsmin(js):
+    ins = StringIO(js)
+    outs = StringIO()
+    JavascriptMinify().minify(ins, outs)
+    str = outs.getvalue()
+    if len(str) > 0 and str[0] == '\n':
+        str = str[1:]
+    return str
+
+def isAlphanum(c):
+    """return true if the character is a letter, digit, underscore,
+           dollar sign, or non-ASCII character.
+    """
+    return ((c >= 'a' and c <= 'z') or (c >= '0' and c <= '9') or
+            (c >= 'A' and c <= 'Z') or c == '_' or c == '$' or c == '\\' or (c is not None and ord(c) > 126));
+
+class UnterminatedComment(Exception):
+    pass
+
+class UnterminatedStringLiteral(Exception):
+    pass
+
+class UnterminatedRegularExpression(Exception):
+    pass
+
+class JavascriptMinify(object):
+
+    def _outA(self):
+        self.outstream.write(self.theA)
+    def _outB(self):
+        self.outstream.write(self.theB)
+
+    def _get(self):
+        """return the next character from stdin. Watch out for lookahead. If
+           the character is a control character, translate it to a space or
+           linefeed.
+        """
+        c = self.theLookahead
+        self.theLookahead = None
+        if c == None:
+            c = self.instream.read(1)
+        if c >= ' ' or c == '\n':
+            return c
+        if c == '': # EOF
+            return '\000'
+        if c == '\r':
+            return '\n'
+        return ' '
+
+    def _peek(self):
+        self.theLookahead = self._get()
+        return self.theLookahead
+
+    def _next(self):
+        """get the next character, excluding comments. peek() is used to see
+           if an unescaped '/' is followed by a '/' or '*'.
+        """
+        c = self._get()
+        if c == '/' and self.theA != '\\':
+            p = self._peek()
+            if p == '/':
+                c = self._get()
+                while c > '\n':
+                    c = self._get()
+                return c
+            if p == '*':
+                c = self._get()
+                while 1:
+                    c = self._get()
+                    if c == '*':
+                        if self._peek() == '/':
+                            self._get()
+                            return ' '
+                    if c == '\000':
+                        raise UnterminatedComment()
+
+        return c
+
+    def _action(self, action):
+        """do something! What you do is determined by the argument:
+           1   Output A. Copy B to A. Get the next B.
+           2   Copy B to A. Get the next B. (Delete A).
+           3   Get the next B. (Delete B).
+           action treats a string as a single character. Wow!
+           action recognizes a regular expression if it is preceded by ( or , or =.
+        """
+        if action <= 1:
+            self._outA()
+
+        if action <= 2:
+            self.theA = self.theB
+            if self.theA == "'" or self.theA == '"':
+                while 1:
+                    self._outA()
+                    self.theA = self._get()
+                    if self.theA == self.theB:
+                        break
+                    if self.theA <= '\n':
+                        raise UnterminatedStringLiteral()
+                    if self.theA == '\\':
+                        self._outA()
+                        self.theA = self._get()
+
+
+        if action <= 3:
+            self.theB = self._next()
+            if self.theB == '/' and (self.theA == '(' or self.theA == ',' or
+                                     self.theA == '=' or self.theA == ':' or
+                                     self.theA == '[' or self.theA == '?' or
+                                     self.theA == '!' or self.theA == '&' or
+                                     self.theA == '|' or self.theA == ';' or
+                                     self.theA == '{' or self.theA == '}' or
+                                     self.theA == '\n'):
+                self._outA()
+                self._outB()
+                while 1:
+                    self.theA = self._get()
+                    if self.theA == '/':
+                        break
+                    elif self.theA == '\\':
+                        self._outA()
+                        self.theA = self._get()
+                    elif self.theA <= '\n':
+                        raise UnterminatedRegularExpression()
+                    self._outA()
+                self.theB = self._next()
+
+
+    def _jsmin(self):
+        """Copy the input to the output, deleting the characters which are
+           insignificant to JavaScript. Comments will be removed. Tabs will be
+           replaced with spaces. Carriage returns will be replaced with linefeeds.
+           Most spaces and linefeeds will be removed.
+        """
+        self.theA = '\n'
+        self._action(3)
+
+        while self.theA != '\000':
+            if self.theA == ' ':
+                if isAlphanum(self.theB):
+                    self._action(1)
+                else:
+                    self._action(2)
+            elif self.theA == '\n':
+                if self.theB in ['{', '[', '(', '+', '-']:
+                    self._action(1)
+                elif self.theB == ' ':
+                    self._action(3)
+                else:
+                    if isAlphanum(self.theB):
+                        self._action(1)
+                    else:
+                        self._action(2)
+            else:
+                if self.theB == ' ':
+                    if isAlphanum(self.theA):
+                        self._action(1)
+                    else:
+                        self._action(3)
+                elif self.theB == '\n':
+                    if self.theA in ['}', ']', ')', '+', '-', '"', '\'']:
+                        self._action(1)
+                    else:
+                        if isAlphanum(self.theA):
+                            self._action(1)
+                        else:
+                            self._action(3)
+                else:
+                    self._action(1)
+
+    def minify(self, instream, outstream):
+        self.instream = instream
+        self.outstream = outstream
+        self.theA = '\n'
+        self.theB = None
+        self.theLookahead = None
+
+        self._jsmin()
+        self.instream.close()
+
+if __name__ == '__main__':
+    import sys
+    jsm = JavascriptMinify()
+    jsm.minify(sys.stdin, sys.stdout)