November 2012 - parenscript-devel - mailman3.common-lisp.net

[parenscript-devel] Bug: let within an outer let's init-form
by Andy Peterson 29 Nov '12

29 Nov '12

If you use a let within the init-form of an outer let, the result is invalid javascript code. Here is a simplified example: (ps (let ((x (let ((y (a))) (b) y))) (1+ x))) ==> "(function () { var y; var x = (y = a(), (b(), y)); return x + 1; })();" Not that I would normally write such code, but the inner "let" was generated by a macro. And many macros use "let"* *with gensyms. In my case, the macro used "ps-once-only". Andy Peterson

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[parenscript-devel] suggestion for json printing
by Canhua 29 Nov '12

29 Nov '12

hi, I think it would be nice to read if parenscript compiler pretty-print json object in the output, in particular properly indent it, rather than print it on one line like right now.

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[parenscript-devel] [PATCH] Lisp-like initialization options for MAKE-ARRAY
by Boris Smilga 29 Nov '12

29 Nov '12

Good day. Please find attached a patch to make Parenscript's MAKE-ARRAY accept a single dimension argument, plus at most one of the keyword arguments INITIAL-CONTENTS or :INITIAL-ELEMENT (plus, optionally, an :ELEMENT-TYPE, which is silently ignored). For reverse compatiblity, any sequence of arguments to MAKE-ARRAY which does not fit the above convention, shall be treated the same as before, that is, formatted as arguments to new Array(). The rationale for the changes is to improve interoperability between PS and Lisp proper. At present, initializing array elements to anything other than the default value (which, in Lisp, is implementation-dependent) requires writing a user-side loop over the array. A couple of unit tests are included in the patch. Yours, — B. Smilga.

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[parenscript-devel] APPLY of method functions
by Boris Smilga 24 Nov '12

24 Nov '12

Hello. I have noticed that the macro APPLY in PS expands to a call to the function's apply method with an invariable “this” as its first argument (thisArg, per http://ecma-international.org/ecma-262/5.1/ #sec-15.3.4.3). When the function is a method of an object, this may result in incorrect code. Consider: (lambda (some-vector start del-count &rest elts) ... (apply (@ some-vector splice) start del-count elts) ... ) => (function (someVector, start, delCount) { var elts = []; for (var i120 = 0; i120 < arguments.length - 3; i120 += 1) { elts[i120] = arguments[i120 + 3]; }; ... someVector.splice.apply(this, [start, delCount].concat(elts)); ... }); Whereas, to be correct, the apply part should go like someVector.splice.apply(someVector, [start, delCount].concat (elts)); Please find attached a patch which makes APPLY recognize property accessors in the function argument, separate them into object and method, and pass the object to the method's apply. For cases which require more fine-grained control, the patch adds an APPLY-TO macro which provides for a completely custom thisArg. There's also a separate patch with a couple of unit tests. Yours, — B. Smilga.

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