Re: Q: Escapes in jsonpath Idents

On 18.03.24 01:09, Erik Wienhold wrote:
>>> The error message 'syntax error at or near "$oo" of jsonpath input' for
>>> the second case ($.f$oo), however, looks as if the scanner identifies
>>> '$oo' as a variable instead of contiuing the scan of identifier (f$oo)
>>> for the member accessor. Looks like a bug to me because a variable
>>> doesn't even make sense in that place.
>> Right. Maybe the docs should be updated to say that a literal dollar
>> sign isn’t supported in identifiers, unlike in JavaScript, except
>> through escapes like this:
> Unfortunately, I don't have access to that part of the SQL spec. So I
> don't know how the jsonpath grammar is specified.

The SQL spec says that <JSON path identifier> corresponds to Identifier
in ECMAScript.

But it also says,

A <JSON path identifier> is classified as follows.

Case:

a) A <JSON path identifier> that is a <dollar sign> is a <JSON path
context variable>.

b) A <JSON path identifier> that begins with <dollar sign> is a
<JSON path named variable>.

c) Otherwise, a <JSON path identifier> is a <JSON path key name>.

Does this help? I wasn't following all the discussion to see if there
is anything wrong with the implementation.