June 2010 - parenscript-devel - mailman3.common-lisp.net

[parenscript-devel] Patch: added JS label/break to PS
by Daniel Gackle 07 Dec '10

07 Dec '10

I just pushed a patch (authored by Scott) to implement JS's LABEL and BREAK in PS. (Note that this patch deprecates LABELED-FOR since you can get the same effect by combining LABEL and FOR. Was anybody using LABELED-FOR?) Here's an example: (label scope (foo) (when (bar) (break scope)) (blee)) => scope: { foo(); if (bar()) { break scope; }; blee(); }; I was astonished to discover recently that JS has supported this ability all along in the form of labeled statements and labeled breaks. I'd always assumed that to get explicit returns from an arbitrary scope, you'd have to resort to the ugly hack of muscling TRY/CATCH to do it, thinking that this was the closest JS counterpart. (See http://news.ycombinator.com/item?id=793092 for a thread in which several people believe this.) But it appears we were all wrong. What's not clear yet is how far this can be taken. Can you use it inside a nested local function to return immediately from the top-level function? That is one thing I've wanted for a long time. In the ideal case, LABEL/BREAK could be used as a base for implementing a proper BLOCK and RETURN-FROM in PS, something which we'd long believed to be impossible. One challenge is that in CL, RETURN-FROM can take a value, which becomes the value of BLOCK. In other words, BLOCK in CL is an expression while LABEL in JS is not. It seems, though, that most of this challenge has already been conquered with the development of implicit return in PS. The only thing you'd need to add is detecting when BLOCK is being used as an expression, declaring a gensymed variable and assigning whatever is happening inside BLOCK to that variable (much like implicit return already does with e.g. CASE), then put the variable in the expression position that BLOCK was in. It seems like this ought to work. It would also make things like this possible in PS: (1+ (case foo (:eleven 11) (:twelve 12))) Vladimir (and everybody), is the above clear? What do you think of it? Daniel

4 11

[parenscript-devel] PS Tests - another run
by Daniel Gackle 13 Jul '10

13 Jul '10

Yes, somehow some errant ps macros made it into the test run I sent a couple days ago. Here's another. (This is from CCL.) Daniel Running reference tests: ...............f......................................................................... Did 89 checks. Pass: 88 (98%) Skip: 0 ( 0%) Fail: 1 ( 1%) Failure Details: -------------------------------- ASSIGNMENT-11 []: (NORMALIZE-JS-CODE "var _js2 = someDiv; var _js1 = 123 + 'px'; _js2.style.left = _js1;") evaluated to "var _js2 = someDiv; var _js1 = 123 + 'px'; _js2.style.left = _js1;", which is not STRING= to "left(someDiv) = 123 + 'px';".. -------------------------------- Running other tests: ....................................................................................................................................................................................................................................... Did 231 checks. Pass: 231 (100%) Skip: 0 ( 0%) Fail: 0 ( 0%) Running Package System tests: f.f..f.. Did 8 checks. Pass: 5 (62%) Skip: 0 ( 0%) Fail: 3 (37%) Failure Details: -------------------------------- NAMESPACE-AND-SPECIAL-FORMS []: (PARENSCRIPT-TEST::NORMALIZE-JS-CODE "var prefix_foo = { prefix_bar : 1, prefix_notAKeyword : prefix_something }; return !prefix_foo && prefix_foo.prefix_bar + prefix_someOtherVar;") evaluated to "var prefix_foo = { prefix_bar : 1, prefix_notAKeyword : prefix_something }; return !prefix_foo && prefix_foo.prefix_bar + prefix_someOtherVar;", which is not COMMON-LISP:STRING= to "var foo = { bar : 1, notAKeyword : something }; return !foo && foo.bar + someOtherVar;".. -------------------------------- -------------------------------- OBFUSCATION1 []: (NORMALIZE-JS-CODE "function g1(a, b, g2) { return a + my_library_libraryFunction(b, g2); };") evaluated to "function g1(a, b, g2) { return a + my_library_libraryFunction(b, g2); };", which is not STRING= to "function g1(a, b, g1) { return a + my_library_libraryFunction(b, g1); };".. -------------------------------- -------------------------------- EXPORTED-INTERFACE []: (PARENSCRIPT-TEST::NORMALIZE-JS-CODE "function interfaceFunction(prefix_baz) { return prefix_baz + g2; };") evaluated to "function interfaceFunction(prefix_baz) { return prefix_baz + g2; };", which is not COMMON-LISP:STRING= to "function interfaceFunction(baz) { return baz + g1; };".. --------------------------------

2 1

[parenscript-devel] A macro for integrating PS with Slime
by Daniel Gackle 11 Jul '10

11 Jul '10

Below is a DEFUN-JS macro for defining PS functions at the Lisp top-level. It creates a Lisp stub with the same signature whose body simply throws an error telling you that you tried to call a PS function from Lisp. Why is that useful? Because now your PS functions are fully integrated with Slime. You can jump around with M-., get arglist info in the minibuffer, and so on. After a week of using this, I can't believe how much of a difference it makes. In PS, DEFUN-JS translates trivially to DEFUN. Of course you still need a way to collect the JS emitted by all these forms, but PS is agnostic on how that should be done. A side note: we also converted nearly all our ps macros to DEFMACRO+PS forms at the toplevel. This has the neat property that you can now look at expansions using the highly convenient Slime macroexpand. I doubt that this is a perfect solution (no doubt you can trip yourself up on differences between the CL and PS macro environments), but it's sure handier than calling PS::PS-MACROEXPAND from the REPL. Daniel p.s. The following has been stripped of a couple of functions specific to our project. I tested it a bit, but if I missed anything, let me know. (defmacro defun-js (name lambda-list &body body) (declare (ignore body)) (labels ((sym% (argspec) (if (symbolp argspec) argspec (car argspec)))) (multiple-value-bind (required optionals restp rest keyp keys allowp auxp aux morep more-context more-count beyond-requireds? key-object) (ps::parse-lambda-list lambda-list) (declare (ignore restp keyp allowp auxp aux morep more-context more-count beyond-requireds? key-object)) ;; get rid of init forms, which can't be evaluated in Lisp. (setf optionals (mapcar #'sym% optionals) keys (mapcar #'sym% keys)) `(defun ,name (,@required ,@(when optionals `(&optional ,@optionals)) ,@(when rest `(&rest ,rest)) ,@(when keys `(&key ,@keys))) (declare (ignore ,@required ,@optionals ,@(when rest (list rest)) ,@keys)) (error "The ~s function is js-only and cannot be called from Lisp." ',name))))) (defpsmacro defun-js (name lambda-list &body body) `(defun ,name ,lambda-list ,@body))

3 3

[parenscript-devel] PS-INLINE fix
by Olof-Joachim Frahm 22 Jun '10

22 Jun '10

Hi, since this came up I attached a one line patch for PS-INLINE, which in the current form won't run, because COMPILE-EXPRESSION? is unbound. Cheers, Olof -- The world is burning. Run.

2 3

[parenscript-devel] A COND clause with unspecified consequent produces a syntax error
by Daniel Gackle 21 Jun '10

21 Jun '10

(ps (setf x (cond ((foo) 123) ((bar)) (t 456)))) => "x = foo() ? 123 : (bar() ? () : 456);" Similarly, (ps (defun blah () (cond ((foo) 123) ((bar)) (t 456)))) => "function blah() { if (foo()) { return 123; } else if (return bar()) { } else { return 456; }; };" No doubt the (bar) form should produce NIL instead, as in CL.

2 1

[parenscript-devel] this.bgcolor
by Haris Bogdanović 21 Jun '10

21 Jun '10

Hi. How to set bgcolor within td tag (cl-who): (:td (ps (setf bgcolor "blue"))) or something like this to get this.bgcolor="blue" ? Thanks

5 9

[parenscript-devel] PS-HTML (Was: this.bgcolor)
by Daniel Gackle 21 Jun '10

21 Jun '10

PS-HTML is indeed what I wanted, or almost (see below). I'm glad this discussion came up. By the way, the documentation page you linked to, which I hadn't looked at in a long time, is very nice. I pushed two small patches to the repository to make PS-HTML do what we need: 1. Use the string-buffer-join technique for concatenating HTML at runtime, since the + operator is notoriously slow when the strings aren't small, at least in older browsers. 2. Expanded the amount of compile-time constant folding of strings that PS-HTML is able to do. For example, if you give it a character, or an expression that macroexpands to a string, these are now joined in with the string literals PS-HTML emits. Apart from reducing the amount of joining needed at runtime, this makes the emitted HTML more readable. If either of these strikes anyone as inappropriate, speak up so we can figure it out together. I'm glad we had this discussion. I did not want to write yet another sexp-html library. Daniel On Sun, Jun 20, 2010 at 1:41 PM, Daniel Gackle <danielgackle(a)gmail.com>wrote: > <Or am I being dumb and you're talking about something else? > > > Not at all, I forgot about it. I think it didn't do what I wanted way > back when, but I'll check it out again and report back. Thanks for > reminding me. > > Dan > > > On Sun, Jun 20, 2010 at 11:56 AM, Vladimir Sedach <vsedach(a)gmail.com>wrote: > >> Parenscript has always had an s-expr HTML markup generator >> ( >> http://common-lisp.net/project/parenscript/reference.html#ssection-html-gen >> ). >> Or am I being dumb and you're talking about something else? >> >> Vladimir >> >> >> 2010/6/20 Daniel Gackle <danielgackle(a)gmail.com>: >> > If I understand correctly, your problem is that you want to express >> > HTML in sexprs à la CL-WHO but with inlined PS expressions >> > to dynamically change what gets emitted. Since you want PS >> > expressions, you must be generating this HTML at runtime in >> > the browser. Is that right? >> > It so happens that I got frustrated with doing the same thing >> > yesterday and wrote a macro to allow me to inline HTML inside >> > PS in this way. Before I post it, though, I want to make sure it >> > at least covers all our existing cases. >> > Can other people pipe up and explain what they do to generate >> > HTML from PS? Is there currently a standard solution better than >> > "<div>"+blah+"</div>"? >> > Daniel >> > >> > 2010/6/20 Haris Bogdanović <fbogdanovic(a)xnet.hr> >> >> >> >> Hi. >> >> >> >> How to set bgcolor within td tag (cl-who): >> >> >> >> (:td (ps (setf bgcolor "blue"))) >> >> >> >> or something like this to get >> >> >> >> this.bgcolor="blue" ? >> >> >> >> Thanks >> >> _______________________________________________ >> >> parenscript-devel mailing list >> >> parenscript-devel(a)common-lisp.net >> >> http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel >> >> >> > >> > >> > _______________________________________________ >> > parenscript-devel mailing list >> > parenscript-devel(a)common-lisp.net >> > http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel >> > >> > >> >> _______________________________________________ >> parenscript-devel mailing list >> parenscript-devel(a)common-lisp.net >> http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel >> > >

1 0

[parenscript-devel] Miscompiled arithmetic expression
by Daniel Gackle 15 Jun '10

15 Jun '10

Just spent two hours tracking down a bug that turned out to be: (ps (- x (+ y z))) => "x - y + z;"

2 1