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[cl-json-devel] Another json-rpc question
by Robert Goldman 01 Jan '10

01 Jan '10

I was testing my error handling code and had some trouble with the restarts in invoke-rpc. A number of these restarts seem to take an error-object as an argument. But when I tested my own CL-JSON methods I couldn't figure out how to get these error-objects into the restart. How is that to be done? thanks, r

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[cl-json-devel] Question about JSON-RPC
by Robert Goldman 30 Dec '09

30 Dec '09

I am setting up a JSON-RPC server over sockets, rather than HTTP, and have a couple of questions about json-rpc.lisp: 1. Am I correct in thinking that INVOKE-JSON does not handle notifications? It looks like it will always try to return a result. Question: would it be reasonable to modify INVOKE-JSON to handle notifications by just executing the function and /not/ returning a result? 2. My socket server must parse JSON messages and decide what type they are before it can call invoke-json. This suggests refactoring invoke-json into two stages: a. the part that calls the decoder and pulls out the three slots b. an inside function that accepts method, params, id, and does the actual invoking. I was thinking of submitting a patch along those lines. Please let me know if that seems wrong. thanks, r

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[cl-json-devel] New encoder
by Henrik Hjelte 03 Dec '09

03 Dec '09

I have added a new alternative encoder to the cl-json darcs repo. I call it the "explicit" (sexp) encoder and now call the old/other (sexp) decoder the "guessing" encoder. The old "guessing" encoder is still the default, so this should not break any code. Also there is a third "streaming" encoder. In other words, flexibility. The "streaming" encoder is a way to format json to a stream. This gives you detailed control, but some of us prefer an intermediate s-exp format. The old "guessing" encoder tries to make a reasonable json representation of a lisp s-expression. For example a list becomes a json array. An a-list becomes a json object. An empty list becomes an empty json array. But some might want it to be json null. Or json false. Or an empty json literal object. With the "explicit" encoder, you give directives in the s-expression explaining exactly what json you want. This might give you more control. Also new is that you can use p-lists to output objects. Also, you can include a pre-formated json string if you wish. I have not updated the documentation, because it was autogenerated by Boris Smilga, and I don't know how to do it. Boris, can you help with this or the code to your doc-maker? There are some testcases and doc-strings explaining the use in the code, I selected one of each and put below in the mail. Also, I have found a bug with json-bind (not fixed, but I have added a testcase for it in case someone want to give it a try). Note that there is no corresponding decoder yet, simply because I have not had any egoistic reasons to add it. But it should be easy if someone want an exercise. Hope someone has a use for this, Henrik "Write the JSON representation of the list S to STREAM (or to *JSON-OUTPUT*), using one of the two rules specified by first calling USE-GUESSING-ENCODER or USE-EXPLICIT-ENCODER. The guessing encoder: If S is a list encode S as a JSON Array, if S is a dotted list encode it as an Object (per ENCODE-JSON-ALIST). The explicit decoder: If S is a list, the first symbol defines the encoding: If (car S) is 'TRUE return a JSON true value. If (car S) is 'FALSE return a JSON false value. If (car S) is 'NULL return a JSON null value. If (car S) is 'JSON princ the strings in (cdr s) to stream If (car S) is 'LIST or 'ARRAY encode (cdr S) as a a JSON Array. If (car S) is 'OBJECT encode (cdr S) as A JSON Object, interpreting (cdr S) either as an A-LIST or a P-LIST." (test explicit-encoder-complex-objects (let ((sample-1-alists `(:object (:method . some-function) (:id . 1) (:params . (:list (:object (:id . bar-id) (:name . bar)) (:true) (:list (:object (:name . a) (:id . b))) (:list (:object (:name . foo) (:id . foo-id))) )))) (sample-2-plists `(:object :method some-function :id 1 :params (:list (:json "{\"id\":\"barId\",\"name\":\"bar\"}") (:true) (:list (:object "name" a :id b)) (:list (:object :name foo :id foo-id)) ))) (correct-json " {\"method\":\"someFunction\", \"id\":1,\"params\": [{\"id\":\"barId\",\"name\":\"bar\"}, true, [{\"name\":\"a\",\"id\":\"b\"}], [{\"name\":\"foo\",\"id\":\"fooId\"}]]}") exact-json sample-1-json sample-2-json) (setf sample-1-json (with-explicit-encoder (encode-json-to-string sample-1-alists))) (setf sample-2-json (with-explicit-encoder (encode-json-to-string sample-2-plists))) (is (string= sample-1-json sample-2-json)) (setf exact-json (remove #\Newline (remove #\Space correct-json :test #'char=) :test #'char=)) (is (string= sample-1-json exact-json))))

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[cl-json-devel] Contrib: simplified camel case
by Leslie P. Polzer 10 Aug '09

10 Aug '09

You might want to include this in camel-case.lisp or contrib. It's barely tested so far though. (defun simplified-camel-case-to-lisp (camel-string) "We don't want + and * all over the place." (declare (string camel-string)) (let ((*print-pretty* nil)) (with-output-to-string (result) (loop for c across camel-string with last-was-lowercase when (and last-was-lowercase (upper-case-p c)) do (princ "-" result) if (lower-case-p c) do (setf last-was-lowercase t) else do (setf last-was-lowercase nil) do (princ (char-upcase c) result))))) Leslie -- http://www.linkedin.com/in/polzer

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[cl-json-devel] Not interning object keys
by Red Daly 10 Aug '09

10 Aug '09

Hello all, CL-JSON does not allow the user to customize the means used to decode the keys for object literals. It may be important to avoid interning in a web setting, for example, since interns of many unique symbols could potentially use a lot of memory. An attack could exploit this by submitting something that is passed through cl-json that has many very large, unique symbols. There used to be a way to get around this with the factory method customization, but the current library does not include a means of changing the decoding behavior for a key to avoid interning it. Unless I am missing something, could this functionality be added? Red

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[cl-json-devel] Javascript parser for Common Lisp
by Red Daly 01 Jul '09

01 Jul '09

Dear CL-JSON and Parenscript developers, I have cloned a functional Javascript parser (from JWACS) and turned it into its own project, which is fully functional but comes with a few annoyances. However, I would appreciate some help coding to make js-parser into a clean package. There are two main issues that need addressing: 1. There are a bunch of warnings about reduce/reduce conflicts in the parser. I couldn't immediately get them out, but I'm sure somebody with more parsing experience should be able to fix the grammar. 2. The project does not use the official, supported version of cl-yacc available here http://www.pps.jussieu.fr/~jch/software/cl-yacc/ Instead it packages its own version, which causes problems if you need the official version of cl-yacc (e.g. closure xml). Theoretically this is a simple change but I don't know for sure. Hopefully this project catches your fancy. I have found a need for a JavaScript parser a bunch of times, from a javascript-to-parenscript converter to screen scraping. Let me know if you would like to contribute. The code is available here: http://github.com/gonzojive/js-parser/tree/master git clone git://github.com/gonzojive/js-parser.git Very truly yours, Red Daly

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[cl-json-devel] (encode-json-to-string "</div>") => "\"<\\/div>\"" ?
by Leslie P. Polzer 17 Jun '09

17 Jun '09

Where do those two extra backslashes in front of the slash come from? Is this intended? Thanks, Leslie -- http://www.linkedin.com/in/polzer

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[cl-json-devel] cl-json 0.4.0
by Henrik Hjelte 25 May '09

25 May '09

A new release of CL-JSON packed with new features is now available, thanks to Boris Smilga and Hans Hübner. * Flexible CLOS decoder * Greatly improved flexibility in customizing both the decoder and encoder. * Various other improvements * Backwards compatible * Good supply of testcases * Precise documentation (online) http://common-lisp.net/project/cl-json Big thanks to Boris! Enjoy, Henrik Hjelte

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[cl-json-devel] cl-json 0.4
by Boris Smilga 03 May '09

03 May '09

Good day to everyone. The bundle attached herewith contains patches to upgrade CL-JSON to the new version 0.4.0 which incorporates changes we have been discussing of late. The changes are rather wide-scale (the sheer size of the patches is 415k), almost every aspect of the implementation differs from what we had in version 0.3.1 and earlier. The most important points are: 1. The decoder now has the customization mechanism from decoder- vars.lisp, with imperative handlers and aggregate-scope variables. 2. The encoder provides a streaming API (borrowed from YASON). The standard encode methods are re-implemented using that API. 3. The CLOS decoder has undergone serious modifications to address the issue of degrading performance in some Lisp implementations. It shall be possible to use anonymous “fluid” objects created by the decoder in a way which makes for a “poor man's JavaScript”. The CLOS encoder does not emit prototype metadata anymore (unless specifically requested). 4. I have written a new pair of matching functions to convert between camel case and Lisp names. 5. There is an improved exception signalling mechanism. Some things which previously were handled by callbacks now use conditions / restarts. 6. JSON-BIND now uses the event-based decoder API with dynamic customization. This has the advantage that the user may choose the semantics with which to decode interior values. However, I had to forego the support for Lisp trees as arguments to JSON-BIND. 7. Some exported names were changed: Condition JSON-PARSE-ERROR → JSON-SYNTAX-ERROR Macro WITH-LIST-DECODER-SEMANTICS → WITH-DECODER-SIMPLE- LIST-SEMANTICS Macro WITH-CLOS-DECODER-SEMANTICS → WITH-DECODER-SIMPLE- CLOS-SEMANTICS I have made sure the tests pass in Clozure CL, SBCL, CMUCL, CLisp, and ECL. There is a new User's Manual in doc/cl-json.html (I have also uploaded a copy to http://dpworks.net/smilga/cl-json.html) And here I would like to humbly ask someone on this mailing list who is a native speaker of English to proof-read it. Russian, my natural idiom, is quite unlike English in grammar, conventional style, and punctuation. Though I am more or less fluent in the latter, I never fully trust myself, especially with the choice of articles, “which” / “that”, and modal and causative constructions. Also, if you think some passages confused or inarticulate, by all means do not hesitate to point me to them. Thank you in advance. Sincerely, - B. Smilga.

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[cl-json-devel] Problem with latest sbcl
by Henrik Hjelte 16 Apr '09

16 Apr '09

Trying the latest patches on todays cvs version of sbcl, 1.0.27.9, totally breaks the testcases. Whereas the old version works. So be a bit careful to use the darcs version for a while in a stable environment. Otherwise, It seems there are lots of cool new features, and the documentation is great. I've put it online here: http://common-lisp.net/project/cl-json/cl-json.html Boris, one thing I am not sure about, the security implications of the clos decoder. How do you make sure that an evil user doesn't create a lispClass ticking-bomb in the lispPackage not-so-secret? Or do I read the docs to bad? Regards, Henrik

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