+;;; Two seperate functions are needed for escaping strings:
+;;; One for producing JavaScript string literals (which are singly or
+;;; doubly quoted)
+;;; And one for producing Lisp strings (which are only doubly quoted)
+;;;
+;;; The same function would suffice for both, but for javascript string
+;;; literals it is neater to use either depending on the context, e.g:
+;;; foo's => "foo's"
+;;; "foo" => '"foo"'
+;;; which avoids having to escape quotes where possible
+(defun js-escape-string (string)
+ (let ((index 0)
+ (size (length string))
+ (seen-single-quote nil)
+ (seen-double-quote nil))
+ (flet ((%js-escape-string (string escape-single-quote-p)
+ (let ((output "")
+ (index 0))
+ (while (< index size)
+ (let ((ch (char string index)))
+ (when (char= ch #\\)
+ (setq output (concat output "\\")))
+ (when (and escape-single-quote-p (char= ch #\'))
+ (setq output (concat output "\\")))
+ (when (char= ch #\newline)
+ (setq output (concat output "\\"))
+ (setq ch #\n))
+ (setq output (concat output (string ch))))
+ (incf index))
+ output)))
+ ;; First, scan the string for single/double quotes
+ (while (< index size)
+ (let ((ch (char string index)))
+ (when (char= ch #\')
+ (setq seen-single-quote t))
+ (when (char= ch #\")
+ (setq seen-double-quote t)))
+ (incf index))
+ ;; Then pick the appropriate way to escape the quotes
+ (cond
+ ((not seen-single-quote)
+ (concat "'" (%js-escape-string string nil) "'"))
+ ((not seen-double-quote)
+ (concat "\"" (%js-escape-string string nil) "\""))
+ (t (concat "'" (%js-escape-string string t) "'"))))))
+
+(defun lisp-escape-string (string)