February 2008 - parenscript-devel - mailman3.common-lisp.net

[parenscript-devel] Generating HTML in parenscript
by Gary King 26 Nov '08

26 Nov '08

I've just started playing with Parenscript and feel confused about HTML generation. Since Parenscript already includes (the unexported) process-html-forms, it seems to be able to (almost) handle much of the logic for simple HTML generation. Consider that > (parenscript::process-html-forms > `(:html > (:head (:title "ParenScript tutorial: 1st example")) > (:body (:h1 "ParenScript tutorial: 1st example") > (:p "Please click the link below." :br > ((:a :href "#" :onclick ,(ps-inline > (alert "Hello World"))) > "Hello World"))))) produces > (+ "<html/><head><title>ParenScript tutorial: 1st example</title></ > head><body><h1>ParenScript tutorial: 1st example</h1><p>Please click > the link below.<br/><a href=\"#\" onclick=\"javascript:alert(\"Hello > World\")\">Hello World</a></p></body>") It's easy to refactor process-html-forms to arrive at the (slightly incorrect) HTML in a string: > "<html/><head><title>ParenScript tutorial: 1st example</title></ > head><body><h1>ParenScript tutorial: 1st example</h1><p>Please click > the link below.<br/><a href=\"#\" onclick=\"javascript:alert(\"Hello > World\")\">Hello World</a></p></body>" and probably easy to futz with *js-inline-string-delimiter* and the like to get the correct quotes around the body of the onclick handler. So... since Parenscript doesn't do this, I have to ask "Why not"?! It would be nice to use Parenscript for simple HTML generation without having to get (Portable) AServe or some other more full-featured HTML generator. Am I missing something? thanks, -- Gary Warren King, metabang.com Cell: (413) 559 8738 Fax: (206) 338-4052 gwkkwg on Skype * garethsan on AIM

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[parenscript-devel] Lisp-like shadowing behavior
by Daniel Gackle 18 Apr '08

18 Apr '08

Below is a ps macro that simulates the shadowing of special variables in Lisp. I'm wondering if anyone thinks this would be useful to add to Parenscript. I wrote it because I have some Javascript functions that reference global variables, and wanted to write some test functions for those without modifying global state. One option of course would be to simply write the original functions to take parameters instead of the global variables. But that complicates their signatures and I'm loath to modify production code to suit tests. With this macro, my test can do this: (ps (shadow-let ((*global-var* "test value")) (function-that-uses-global-var))) and the original value of *global-var* will be restored: var _js3778 = null; try { _js3778 = GLOBALVAR; GLOBALVAR = 'test value'; functionThatUsesGlobalVar(); } finally { GLOBALVAR = _js3778; }; Daniel ------------------------------------------------------------------------ (defpsmacro shadow-let (bindings &body body) (labels ((wrap-expr (bindings body) (if (null bindings) body (list (list 'temporarily-bind (car bindings) (wrap-expr (cdr bindings) body)))))) `(macrolet ((temporarily-bind ((var expr) body) (with-ps-gensyms (temp) `(progn (defvar ,temp nil) (try (progn (setf ,temp ,var) (setf ,var ,expr) ,@body) (:finally (setf ,var ,temp))))))) ,(cons 'progn (wrap-expr bindings body)))))

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[parenscript-devel] automate javascript -> parenscript conversion
by Lui Fungsin 15 Feb '08

15 Feb '08

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

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[parenscript-devel] Add #\= to *special-chars*?
by Daniel Gackle 01 Feb '08

01 Feb '08

Can we add #\= to *special-chars* so that instead of this: (ps blah=) => "blah=;" we get something like this: (ps blah=) => "blahequals;" ? Dan

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[parenscript-devel] Bug in setf
by Daniel Gackle 01 Feb '08

01 Feb '08

There's a bug when using setf to decrement a variable: (ps (setf x (- x 1 2))) => "x -= 1 - 2;" Note that this works correctly: (ps (setf x (- 1 x 2))) => "x = 1 - x - 2;" Dan

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