JSON Parsing Edge Case

JSON Parsing Edge Case

[T.V Raman]

The following happens with both json-read  -- the elisp implementation
as well as json-parse-string  implemented in C --

Try this json fragment --  by typing it into an empty buffer:

{"quote": "1"}

The above is a json dict with one key -- "quote" -- with value 1.

Parsing this into an emacs alist -- either with (json-read) or
(json-parse-buffer)
yields  the following lisp structure -- 

('. "1")

the list structure is really 

(quote . "1")

but the elisp reader has turned that symbol "quote" into an "'"
-- 

Re: JSON Parsing Edge Case

[Noam Postavsky]

On 10 May 2018 at 19:48, T.V Raman <raman@google.com> wrote:
> The following happens with both json-read  -- the elisp implementation
> as well as json-parse-string  implemented in C --
>
> Try this json fragment --  by typing it into an empty buffer:
>
> {"quote": "1"}
>
> The above is a json dict with one key -- "quote" -- with value 1.
>
> Parsing this into an emacs alist -- either with (json-read) or
> (json-parse-buffer)
> yields  the following lisp structure --
>
> ('. "1")

With json-read, and (json-read-from-string "{\"quote\": \"1\"}"), I get

 ((quote . "1"))

json-parse-string and json-parse-buffer don't seem to exist for me
(using the latest master branch).

Re: JSON Parsing Edge Case

[T.V Raman]

Noam Postavsky <npostavs@gmail.com> writes:

I meant  json-read-string --apologies. json-parse-buffer needs the
underlying emacs to be compiled with the json C module.
> On 10 May 2018 at 19:48, T.V Raman <raman@google.com> wrote:
>> The following happens with both json-read  -- the elisp implementation
>> as well as json-parse-string  implemented in C --
>>
>> Try this json fragment --  by typing it into an empty buffer:
>>
>> {"quote": "1"}
>>
>> The above is a json dict with one key -- "quote" -- with value 1.
>>
>> Parsing this into an emacs alist -- either with (json-read) or
>> (json-parse-buffer)
>> yields  the following lisp structure --
>>
>> ('. "1")
>
> With json-read, and (json-read-from-string "{\"quote\": \"1\"}"), I get
>
>  ((quote . "1"))
>
> json-parse-string and json-parse-buffer don't seem to exist for me
> (using the latest master branch).
>

-- 

Re: JSON Parsing Edge Case

[Basil L. Contovounesios]

"T.V Raman" <raman@google.com> writes:

> Noam Postavsky <npostavs@gmail.com> writes:
>
> I meant  json-read-string --apologies. json-parse-buffer needs the
> underlying emacs to be compiled with the json C module.
>> On 10 May 2018 at 19:48, T.V Raman <raman@google.com> wrote:
>>> The following happens with both json-read  -- the elisp implementation
>>> as well as json-parse-string  implemented in C --
>>>
>>> Try this json fragment --  by typing it into an empty buffer:
>>>
>>> {"quote": "1"}
>>>
>>> The above is a json dict with one key -- "quote" -- with value 1.
>>>
>>> Parsing this into an emacs alist -- either with (json-read) or
>>> (json-parse-buffer)
>>> yields  the following lisp structure --
>>>
>>> ('. "1")
>>
>> With json-read, and (json-read-from-string "{\"quote\": \"1\"}"), I get
>>
>>  ((quote . "1"))
>>
>> json-parse-string and json-parse-buffer don't seem to exist for me
>> (using the latest master branch).
>>

FWIW, after emacs -Q and (require 'json), the following four forms all
evaluate to ((quote . "1")) on my end:

(with-temp-buffer
  (insert "{\"quote\": \"1\"}")
  (goto-char (point-min))
  (json-read))

(with-temp-buffer
  (insert "{\"quote\": \"1\"}")
  (goto-char (point-min))
  (json-parse-buffer :object-type 'alist))

(json-read-from-string "{\"quote\": \"1\"}")

(json-parse-string "{\"quote\": \"1\"}" :object-type 'alist)

AFAICT the json.el function json-read-string is for reading a single
JSON string at point, not a whole object.

-- 
Basil

In GNU Emacs 27.0.50 (build 20, x86_64-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2018-05-10 built on thunk
Repository revision: 766b057e41df7316808ec7658836fda75facda75
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description: Debian GNU/Linux buster/sid

Configured using:
 'configure 'CC=ccache gcc' 'CFLAGS=-march=native -O2 -pipe'
 --config-cache --prefix=/home/blc/.local --with-mailutils
 --with-x-toolkit=lucid --with-modules --with-file-notification=yes
 --with-x'

Configured features:
XAW3D XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS LUCID X11 MODULES THREADS LIBSYSTEMD JSON LCMS2