It seems to me, on the contrary, that the deficiency is in the pointer syntax, and I think it would be a mistake to try to work around that deficiency in JSON Patch. Because aren't there other things which one might do with JSON Pointer than use it with JSON Patch? There's been mention of having it registered as a URI fragment identifier syntax for JSON for example. JSON Pointers could then end up all over the place, outside of patches. IMHO JSON Pointer needs to be taken seriously as a technology in its own right.On 07/01/13 13:23, Matthew Morley wrote:
For me the deficiency is not in the pointer, but patch format being generated.
One approach is to push that *one* test, structure conformity, into the pointer syntax. Another is via the type operation.
If a vague patch is generated, vague results are to be expected.
Couldn't agree more about it being taken seriously in its own right. :)
JSON Pointer for me exists outside of JSON Patch, always has and will do the way we think about structures. As it represents both a resolution path and an identity string (both ends of the path concept). I see value from the identity view, in describing a location that is aware of being inside an array.
But JSON Pointer should not be changed just because of issues with JSON Patch, especially when JSON Patch is attempting to address those issues with other mechanisms within the specification. That is all I was trying to express. The syntax change should be for other reasons, if it is going to be made.
My personal experience (for what its worth): In the past I've tried a number of syntaxes like JSON Pointer. Mostly a.b.c.0 and even a.b.c:0 at times to address the same issues suggested here. Though my experiences pushed me towards a single syntax using a.b.c.0, and thus my support for /a/b/c/0 over /a/b/c:0.
The system at first used the . or : syntax, combined with dynamic tokens, being pointers themselves, to resolve other pointers. So it was not reasonable to know ahead of time if an end point was an array or an object. "a.b.c.{d.e.f}" could end up in an array or in an object, depending on the value at d.e.f at the time of resolution. Especially with many layers of tokens to resolve, and changing data structures.
I found in practice, it didn't really matter, so the choice of . or : was phased out. At the end of the day the two syntaxes point to mutually exclusive points within the data, so that `meta data` about the structure was removed from the syntax we used. It didn't add value, even if it added clarity at times. We also had functions at the end of paths, but that goes beyond the JSON focus of the JSON Pointer goals, so those points are not relevant here.
The system at first used the . or : syntax, combined with dynamic tokens, being pointers themselves, to resolve other pointers. So it was not reasonable to know ahead of time if an end point was an array or an object. "a.b.c.{d.e.f}" could end up in an array or in an object, depending on the value at d.e.f at the time of resolution. Especially with many layers of tokens to resolve, and changing data structures.
I found in practice, it didn't really matter, so the choice of . or : was phased out. At the end of the day the two syntaxes point to mutually exclusive points within the data, so that `meta data` about the structure was removed from the syntax we used. It didn't add value, even if it added clarity at times. We also had functions at the end of paths, but that goes beyond the JSON focus of the JSON Pointer goals, so those points are not relevant here.
This discussion thread seems to be getting overly complicated, but JSON Pointer changes should come from the JSON Pointer view point and that specifications goals, not from short comings in JSON Patch.
Matthew P. C. Morley