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[cl-json-devel] bug report
by Nicolas Martyanoff 05 Jun '11

05 Jun '11

Hi, The following form breaks when evaluated: (json:encode-json-to-string '((:a . ((:b . ((:c . 42))))))) Help! 11 nested errors. SB-KERNEL:*MAXIMUM-ERROR-DEPTH* exceeded. 0: (SB-DEBUG::MAP-BACKTRACE #<CLOSURE (LAMBDA (SB-DEBUG::FRAME)) {10032BDAF9}> :START 0 :COUNT 1152921504606846975) 1: (BACKTRACE 1152921504606846975 #<SYNONYM-STREAM :SYMBOL SB-SYS:*TTY* {100021E341}>) 2: ((LAMBDA NIL)) 3: (SB-IMPL::%WITH-STANDARD-IO-SYNTAX #<CLOSURE (LAMBDA NIL) {10032BDAB9}>) 4: (SB-IMPL::ERROR-ERROR "Help! " 11 " nested errors. " "SB-KERNEL:*MAXIMUM-ERROR-DEPTH* exceeded.") 5: (SB-IMPL::INFINITE-ERROR-PROTECTOR) 6: (ERROR JSON:UNENCODABLE-VALUE-ERROR :DATUM (:C . 42) :CONTEXT JSON:ENCODE-JSON) 7: (JSON:UNENCODABLE-VALUE-ERROR (:C . 42) JSON:ENCODE-JSON) 8: (SIGNAL #<TYPE-ERROR expected-type: LIST datum: 42>) 9: (ERROR TYPE-ERROR :DATUM 42 :EXPECTED-TYPE LIST) 10: (SB-KERNEL::OBJECT-NOT-LIST-ERROR-HANDLER #<unavailable argument> #.(SB-SYS:INT-SAP #X7FFFF6D8CC20) #<SB-ALIEN-INTERNALS:ALIEN-VALUE :SAP #X7FFFF6D8C600 :TYPE (* (STRUCT SB-VM::OS-CONTEXT-T-STRUCT))> (405)) 11: (SB-KERNEL:INTERNAL-ERROR #.(SB-SYS:INT-SAP #X7FFFF6D8C600) #<unavailable argument>) 12: ("foreign function: #x417860") debugger invoked on a SIMPLE-ERROR in thread #<THREAD "initial thread" RUNNING {1002990EE1}>: Maximum error nesting depth exceeded Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL. restarts (invokable by number or by possibly-abbreviated name): 0: [ABORT] Exit debugger, returning to top level. Regards, -- Nicolas Martyanoff http://codemore.org khaelin(a)gmail.com

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[cl-json-devel] jsonp
by Haris 13 Apr '11

13 Apr '11

Hi. Can someone give me an example of using jsonp ? For example, I have a lisp function: (defun add (x y) (+ x y)) and I want to call it from javascript: add (2, 2); How do I do that ? Thanks

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Re: [cl-json-devel] Newbie to Lisp question, trying to create JSON
by Henrik Hjelte 12 Apr '11

12 Apr '11

>> On Thu, Apr 7, 2011 at 4:07 PM, Jim Barrows <jim.barrows(a)gmail.com> wrote: >>> >>> I'm trying to encode a list of plists, and encode-json-plist-to-string >>> doesn't appear to do it. >> >> Yes, because the first list is a list and not a plist. > > > Am I incorrect in thinking this is a list of plists? I'm still in shock > over the difference in terminology between Java and Lisp... And I am often shocked when I need to do various things in the Java world, so I understand your reaction. No your right, it is a list of p-lists. But the encode-json-plist function is for p-lists, not necessarily lists of p-lists. It is an easy way to render a simple key-value object. Probably not the best choice if you want to have control over details, then I suggest the explicit encoder. The problem is for the encoder to guess what you intend to have as output. A p-list looks just like a list, so what do you want as output, an object or a list? How should a nested list (one of the values in the key-value pair) that looks like a p-list be converted, to a json-list or a json-object? It is slightly easier with a-lists, I think you will get a list of objects if you have a list of a-lists and encode-json-alist. Or if you don't like the unpredictable ways of some code trying to guess what you want, just use the explicit encoder or the streaming encoder, then you have full control. Look at the testcases for lots of examples. /Henrik

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[cl-json-devel] ajax
by Haris 08 Apr '11

08 Apr '11

Hi. How to do ajax with cl-json on Hunchentoot ? Can you give me a simple example, calling a lisp function from javascript ? Thanks

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[cl-json-devel] installation
by Haris 08 Apr '11

08 Apr '11

Hi. I did (asdf:oos 'asdf:load-op 'cl-json) but I get: Package not found error in Lispworks (when I write cl-json: and hit tab in repl) ? What do I write in command line (Windows) to get the Darcs version ? Thanks

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[cl-json-devel] Newbie to Lisp question, trying to create JSON
by Jim Barrows 07 Apr '11

07 Apr '11

I'm trying to encode a list of plists, and encode-json-plist-to-string doesn't appear to do it. My newbiness is not seeing a better answer then to loop through the list, and encode each plist separately, concatentate the strings together to form the array. That doesn't seem too lispy to me. Is there a better way? -- James A Barrows

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[cl-json-devel] Is cl-json thread-safe?
by Jianshi Huang 15 Nov '10

15 Nov '10

Hi, I'd like to ask if using `with-local-class-registry' will make the decoder thread-safe, is that correct (and tested)? Cheers, Jianshi

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[cl-json-devel] issue with encode-json-from-string when it comes to null
by Henrik Hjelte 19 Aug '10

19 Aug '10

Got a message from a non-member that was stuck in mailman, and I don't know how to retrieve my lost list administrator password. So I just yank it below: Hey Everyone, I have noticed a bit of weird behavior from the json package and was wondering if someone can help me by pointing out what is going on and more importantly why this behavior. - In the below you can see that decode the json string and encoding it results in the output equal to the input as is expected: CL-USER> (json:ENCODE-JSON-TO-STRING (json:decode-json-from-string "{\"available\":true}")) "{\"available\":true}" -Now the issue appears when one attempts to encode the false value as can be seen from the below. As you can see the problem from the second line the real issue is in the encoding of the nil value. CL-USER> (json:ENCODE-JSON-TO-STRING (json:decode-json-from-string "{\"available\":false}")) "[[\"available\"]]" CL-USER> (json:ENCODE-JSON-TO-STRING `((:available . nil))) "[[\"available\"]]" Can anyone point out how to fix this especially that the docs point out that nil will be transformed to null. Thanks to any help you can provide. Regards, Mackram Raydan And my answer is: cl-json has three encoders, for historical reasons the default is the guessing encoder. It has difficulties correctly guessing if nil is false or an empty list. If you want more control I suggest using the explicit encoder. Here are some samples, there are more examples in testencoder.lisp, in particular check the explicit-encoder-complex-objects test. This is in the darcs version, which is the latest version. Hope this helps, Henrik JSON> (json:decode-json-from-string "{\"available\":true}") ((:AVAILABLE . T)) JSON> (json:encode-json-to-string '((:AVAILABLE . T))) "{\"available\":true}" JSON> (json:encode-json-to-string '((:AVAILABLE . nil))) "[[\"available\"]]" JSON> (with-guessing-encoder (json:encode-json-to-string '((:AVAILABLE . nil)))) "[[\"available\"]]" (you see guessing encode is default) JSON> (with-explicit-encoder (json:encode-json-to-string '(:object (:avaliable . nil)))) "{\"avaliable\":null}" JSON> (with-explicit-encoder (json:encode-json-to-string '(:object (:avaliable . :false)))) "{\"avaliable\":\"false\"}" JSON> (with-explicit-encoder (json:encode-json-to-string '(:object (:avaliable . :true)))) "{\"avaliable\":\"true\"}" JSON> (with-explicit-encoder (encode-json-to-string `(:object :available ,(json-bool (if t t nil))))) "{\"available\":true}" JSON> (with-explicit-encoder (encode-json-to-string `(:object :available ,(json-bool (if nil t nil))))) "{\"available\":false}"

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[cl-json-devel] How to get a JS false from cl-json?
by Henrik Hjelte 20 May '10

20 May '10

This question got stuck in mailman, From: Kenneth Tilton <ktilton(a)franz.com> To: cl-json-devel(a)common-lisp.net Date: Wed, 19 May 2010 16:14:31 -0400 Subject: How to get a JS false from cl-json? t changes to unquoted true nicely, how about something that becomes false? I see there is a choice between null and false so we cannot just do false all the time. nice lib, btw. kt And the answer is: There are 3 different encoders. With the "streaming" encoder you have full control of the output. The guessing encoder (default) tries to make a decent json representation of a s-expression, it does not discriminate between null and false. The pretty new explicit encoder gives more control over the json representation, using a keyword in the first position of a list: (test explicit-encoder (is (string= "true" (with-explicit-encoder (encode-json-to-string '(:true)))) "True") (is (string= "false" (with-explicit-encoder (encode-json-to-string '(:false)))) "False") (is (string= "null" (with-explicit-encoder (encode-json-to-string '(:null)))) "False") There is a convenience function json-bool to make the keyword represenation: (test json-bool (is (equal (json-bool t) '(:true))) (is (equal (json-bool 1) '(:true))) (is (equal (json-bool nil) '(:false)))) Also a related question is how to encode an empty list. As an empty json object {}, empty json-list [] or as json-null? That can also be handled with the explicit encoder. Here is a sample how a complex json structure can be built (from testencoder.lisp) (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\"}]]}") /Henrik Hjelte

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[cl-json-devel] Problem encoding PLists on Clozure Common Lisp
by Ron Garret 26 Mar '10

26 Mar '10

Using cl-json-0.4.0 on the latest CCL trunk, encoding PLists results in a hard error: (encode-json-to-string '((x . 123))) > Error: Fault during read of memory address #x3DD

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