Implement shebang support

lib/output.js

@@ -60,6 +60,7 @@ function OutputStream(options) {
         bracketize       : false,
         semicolons       : true,
         comments         : false,
+        shebang          : true,
         preserve_line    : false,
         screw_ie8        : false,
         preamble         : null,
@@ -403,7 +404,6 @@ function OutputStream(options) {
 
     AST_Node.DEFMETHOD("add_comments", function(output){
         var c = output.option("comments"), self = this;
-        if (c) {
         var start = self.start;
         if (start && !start._comments_dumped) {
             start._comments_dumped = true;
@@ -426,13 +426,17 @@ function OutputStream(options) {
                 }));
             }
 
-                if (c.test) {
+            if (!c) {
+                comments = comments.filter(function(comment) {
+                    return comment.type == "comment5";
+                });
+            } else if (c.test) {
                 comments = comments.filter(function(comment){
-                        return c.test(comment.value);
+                    return c.test(comment.value) || comment.type == "comment5";
                 });
             } else if (typeof c == "function") {
                 comments = comments.filter(function(comment){
-                        return c(self, comment);
+                    return c(self, comment) || comment.type == "comment5";
                 });
             }
 
@@ -458,8 +462,11 @@ function OutputStream(options) {
                         output.space();
                     }
                 }
-                });
+                else if (output.pos() === 0 && c.type == "comment5" && output.option("shebang")) {
+                    output.print("#!" + c.value + "\n");
+                    output.indent();
                 }
+            });
         }
     });
 

lib/parse.js

@@ -210,7 +210,7 @@ function is_token(token, type, val) {
 
 var EX_EOF = {};
 
-function tokenizer($TEXT, filename, html5_comments) {
+function tokenizer($TEXT, filename, html5_comments, shebang) {
 
     var S = {
         text            : $TEXT,
@@ -568,6 +568,13 @@ function tokenizer($TEXT, filename, html5_comments) {
         if (PUNC_CHARS(ch)) return token("punc", next());
         if (OPERATOR_CHARS(ch)) return read_operator();
         if (code == 92 || is_identifier_start(code)) return read_word();
+
+        if (shebang) {
+            if (S.pos == 0 && looking_at("#!")) {
+                forward(2);
+                return skip_line_comment("comment5");
+            }
+        }
         parse_error("Unexpected character '" + ch + "'");
     };
 
@@ -637,12 +644,13 @@ function parse($TEXT, options) {
         expression     : false,
         html5_comments : true,
         bare_returns   : false,
+        shebang        : true,
     });
 
     var S = {
         input         : (typeof $TEXT == "string"
                          ? tokenizer($TEXT, options.filename,
-                                     options.html5_comments)
+                                     options.html5_comments, options.shebang)
                          : $TEXT),
         token         : null,
         prev          : null,