October 2011 - parenscript-devel - mailman3.common-lisp.net

[parenscript-devel] bug: RETURN-FROM doesn't work with LABELS
by Daniel Gackle 17 Dec '11

17 Dec '11

This produces incorrect code (a throw with no corresponding catch): (defun foo () (labels ((bar (x) (when (evenp x) (return-from bar "even")) (blah x))) (bar 9))) If you change LABELS to FLET then it works. Daniel

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[parenscript-devel] [PATCH] Implementation of TRY-EXPRESSIONIZE-IF? that doesn't call the printer.
by sblist＠me.com 17 Dec '11

17 Dec '11

I needed to avoid secondary calls to the printer for the purpose of generating source mappings, but this seems like a more precise definition anyway (unless I've missed something). Scott --- src/special-operators.lisp | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-) diff --git a/src/special-operators.lisp b/src/special-operators.lisp index 3a77ae5..be95a5f 100644 --- a/src/special-operators.lisp +++ b/src/special-operators.lisp @@ -130,10 +130,16 @@ `(ps-js:label ,name ,(wrap-block-for-dynamic-return name (compile-statement `(progn ,@body)))))) (defun try-expressionize-if? (form) - (< (count #\Newline (with-output-to-string (*psw-stream*) - (let ((*ps-print-pretty* t)) - (parenscript-print (compile-statement form) t)))) - (if (= (length form) 4) 5 4))) + (destructuring-bind (if condition + (block . consequent) + &optional + else + alternative-block) + (compile-statement form) + (declare (ignore if condition else block)) + (and (= (length consequent) 1) + (or (null alternative-block) + (= (length alternative-block) 2))))) (define-statement-operator return-from (tag &optional result) (if (not tag) -- 1.7.6

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[parenscript-devel] "let over lambda" seems buggy
by Canhua 17 Dec '11

17 Dec '11

hi, all, I found that (create "fn" (let ((x)) (lambda () x))) compiles to { 'fn' : (x = null, function () { return x; }) } wherein the variable x may conflict with a variable with the same name outside this code. How may avoid this? How may I achieve "let over lambda" closure effect as in common lisp? Thanks.

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[parenscript-devel] Bug: RETURN-FROM inside a lambda doesn't return anything
by Daniel Gackle 12 Dec '11

12 Dec '11

I thought this was working at some point, but it doesn't seem to now. FOO() returns undefined in JS, when it should return 123: (defun bar (fn) (funcall fn)) (defun foo () (bar (lambda () (return-from foo 123)))) It seems the value stored under the name "ps-return-value" isn't actually returned: function foo() { try { return bar(function () { throw { 'ps-block-tag' : 'foo', 'ps-return-value' : 123 }; }); } catch (err) { if (err && 'foo' === err['ps-block-tag']) { err['ps-return-value']; } else { throw err; }; }; };

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[parenscript-devel] BLOCK/RETURN-FROM
by sblist＠me.com 12 Dec '11

12 Dec '11

Hi, I was wondering if the BLOCK/RETURN-FROM feature in PS intends to support the following case: (ps (defun foo () (flet ((bar () (return-from foo 42))) (bar)))) => WARNING: Returning from unknown block FOO "function foo() { var bar = function () { return 42; }; return bar(); };" In order to try and get around the warning, I tried this: (ps (defun baz () (block foo (flet ((bar () (return-from foo 42))) (bar))))) => WARNING: Returning from unknown block FOO "function baz() { var bar = function () { return 42; }; return bar(); };" but that didn't seem to work. Any ideas on how to achieve lexical return here? - Scott

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Re: [parenscript-devel] what's wrong?
by F D 12 Dec '11

12 Dec '11

Yes it helps. Many Thanks, I made a mistake and forgot to use a (lambda...) Is there something that can help to convert js code to parenscript code? FD

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