Re: [PATCH] Support custom 'null' and 'false' objects when parsing JSON

["João Távora" <joaotavora@gmail.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> the keyword :null, I have to explicitly check for non-`nil'ness *and*
>> non-`:null'ness, whereas before only one check was necessary.  Other
>
> IIUC this is a matter of changing things like
>
>     (null x)
> to
>     (memq x '(nil :null))
>
> right?  On this one example it doesn't look that bad

More like from

  x

to

  (not (memq x '(nil :null)))

or to

  (and (not (memq x '(nil :null))) x)

if you're planning on destructuring x

Not exactly pretty.  Sure, I could change `when's to `unless`es, or wrap
that in a macro, but still akward.

Also, I don't see why we shouldn't work towards some (or total) json.el
compatibility, presuming it's easy and cheap like in this case here.

>> -json_to_lisp (json_t *json, enum json_object_type object_type)
>> +json_to_lisp (json_t *json,
>> +              enum json_object_type object_type,
>> +              Lisp_Object null_object,
>> +              Lisp_Object false_object)
>
> Wouldn't it make sense to group those 3 parameters into a single object
> (presumably a pointer to a stack-allocated struct containing those
> 3 fields)?

Yes it would, good idea.

João