add _meta for all mapping fields

[kzwang]

add field level _meta support for all fields in mapping

closes #2857

[imotov]

Hi @kzwang,

Thanks for the pull request. I see that it adds _meta tag not only to document fields but also to all metadata fields (such as _id, _parent, _analyzer, etc.). While I can clearly see the value for having _meta tag on the field level, I am not sure I like the idea of having it (and need to maintain it) for the metadata fields. Is there a particular reason you need it there?

Igor

[clintongormley]

Hi @kzwang - I'd be interested in hearing the use case too.

I'm assuming that the intent is to use the _meta element for some object<->es mapper, and wondering if and why meta entries are necessary on the special fields.

[clintongormley]

Closing.

[mindbits]

I think having _meta on a field level is a great way to avoid lookup tables and use cases would range from comments to access control list information etc.