Hi,
I found that manually converting javascript (sample code) to parenscript is quite annoying.
Does anyone know if writing a parser/converter (in lisp, perhaps) to automate this task is a major undertaking or is relatively easy? (maybe using some of the existing lisp libraries)
The reason to convert existing javascript to parenscript is that it's easier to write/maintain afterwards (you have macro, emacs's paredit mode, etc). Also, it's a lot easier to integrate in-line with cl-who or other similar libraries whereas with existing javascript you need to link them with the script tag (otherwise you have to escape all the quotes, backslashes etc to include it as a really longggggg string).
From my experience of converting existing javascript code to
parenscript, the oo method call conversion is most troublesome.
i.e. x.getobj().slot1.slot2.method1()
/* hard to read backward if you're used to js */ => (.method (aref (aref (.getobj x) "slot1") "slot2"))
/* easier to read but required a temp variable */ or (let ((obj (.getobj x))) (.method1 obj.slot1.slot2))
thanks
Lui,
Appologies for a rushed email:
I wrote something to do this awhile ago, and it is fairly functional.
get the Suave source from http://common-lisp.net/project/suave/
look at the experimental/js-on-cl folder. load up the ASD and use JS-TO-PAREN. the key file is src/js-to-parenscript.lisp, which comes with an example:
(defvar *example-script* "function getElementPosition(elemID) { var offsetTrail = document.getElementById(elemID); var offsetLeft = 0; var offsetTop = 0; while (offsetTrail) { offsetLeft += offsetTrail.offsetLeft; offsetTop += offsetTrail.offsetTop; offsetTrail = offsetTrail.offsetParent; } if (navigator.userAgent.indexOf("Mac") != -1 && typeof document.body.leftMargin != "undefined") { offsetLeft += document.body.leftMargin; offsetTop += document.body.topMargin; } return {left:offsetLeft, top:offsetTop}; }")
(defun example-usage () (js-to-paren *example-script*))
The hard work for this is the Javascript parser, which was stolen from JWACS.
I'm not sure if this all still works as Parenscript has changed somewhat since then. Your patches are welcome, just send them to the Suave list.
Best, Red
Lui Fungsin wrote:
Hi,
I found that manually converting javascript (sample code) to parenscript is quite annoying.
Does anyone know if writing a parser/converter (in lisp, perhaps) to automate this task is a major undertaking or is relatively easy? (maybe using some of the existing lisp libraries)
The reason to convert existing javascript to parenscript is that it's easier to write/maintain afterwards (you have macro, emacs's paredit mode, etc). Also, it's a lot easier to integrate in-line with cl-who or other similar libraries whereas with existing javascript you need to link them with the script tag (otherwise you have to escape all the quotes, backslashes etc to include it as a really longggggg string).
From my experience of converting existing javascript code to
parenscript, the oo method call conversion is most troublesome.
i.e. x.getobj().slot1.slot2.method1()
/* hard to read backward if you're used to js */ => (.method (aref (aref (.getobj x) "slot1") "slot2"))
/* easier to read but required a temp variable */ or (let ((obj (.getobj x))) (.method1 obj.slot1.slot2))
thanks _______________________________________________ parenscript-devel mailing list parenscript-devel@common-lisp.net http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel
Wow, it's really cool. You're right, the javascript parser is not trivial at all.
BTW, I notice that the experimental/js-on-cl/test/ directory is empty and for some reason after lispworks 5 (linux) finshed loading the asd system, the example-usage function is still undefined.
SBCL 1.10 failed the first time I tried to load js-on-cl.asd but on second trial the error is gone.
The output of (example-usage) is very nice, except for all the CAPS :-)
Thanks a lot. I'll follow up on the mailing lists if I notice other issues (or if I have any patch for submit)
Regards, fungsin
On 2/14/08, Red Daly reddaly@stanford.edu wrote:
Lui,
Appologies for a rushed email:
I wrote something to do this awhile ago, and it is fairly functional.
get the Suave source from http://common-lisp.net/project/suave/
look at the experimental/js-on-cl folder. load up the ASD and use JS-TO-PAREN. the key file is src/js-to-parenscript.lisp, which comes with an example:
(defvar *example-script* "function getElementPosition(elemID) { var offsetTrail = document.getElementById(elemID); var offsetLeft = 0; var offsetTop = 0; while (offsetTrail) { offsetLeft += offsetTrail.offsetLeft; offsetTop += offsetTrail.offsetTop; offsetTrail = offsetTrail.offsetParent; } if (navigator.userAgent.indexOf("Mac") != -1 && typeof document.body.leftMargin != "undefined") { offsetLeft += document.body.leftMargin; offsetTop += document.body.topMargin; } return {left:offsetLeft, top:offsetTop}; }")
(defun example-usage () (js-to-paren *example-script*))
The hard work for this is the Javascript parser, which was stolen from JWACS.
I'm not sure if this all still works as Parenscript has changed somewhat since then. Your patches are welcome, just send them to the Suave list.
Best, Red
Lui Fungsin wrote:
Hi,
I found that manually converting javascript (sample code) to parenscript is quite annoying.
Does anyone know if writing a parser/converter (in lisp, perhaps) to automate this task is a major undertaking or is relatively easy? (maybe using some of the existing lisp libraries)
The reason to convert existing javascript to parenscript is that it's easier to write/maintain afterwards (you have macro, emacs's paredit mode, etc). Also, it's a lot easier to integrate in-line with cl-who or other similar libraries whereas with existing javascript you need to link them with the script tag (otherwise you have to escape all the quotes, backslashes etc to include it as a really longggggg string).
From my experience of converting existing javascript code to
parenscript, the oo method call conversion is most troublesome.
i.e. x.getobj().slot1.slot2.method1()
/* hard to read backward if you're used to js */ => (.method (aref (aref (.getobj x) "slot1") "slot2"))
/* easier to read but required a temp variable */ or (let ((obj (.getobj x))) (.method1 obj.slot1.slot2))
thanks _______________________________________________ parenscript-devel mailing list parenscript-devel@common-lisp.net http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel
parenscript-devel mailing list parenscript-devel@common-lisp.net http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel
parenscript-devel@common-lisp.net
-
Lui Fungsin -
Red Daly