This gives better coverage and consistency with the scripting APIs, by
whitelisting the primary search scripting API classes and using them instead
of only Map and List methods.
For example, accessing fields can now be done with `.value` instead of `.0`
because `getValue()` is whitelisted. For now, access to a document's fields in
this way (loads) are fast-pathed in the code, to avoid dynamic overhead.
Access to geo fields and geo distance functions is now supported.
TODO: date support (e.g. whitelist ReadableDateTime methods as a start)
TODO: improve docs (like expressions and groovy have for document's fields)
TODO: remove fast-path hack
Closes#18169
Squashed commit of the following:
commit ec9f24b2424891a7429bb4c0a03f9868cba0a213
Author: Robert Muir <rmuir@apache.org>
Date: Thu May 5 17:59:37 2016 -0400
cutover to <Def> instead of <Object> here
commit 9edb1550438acd209733bc36f0d2e0aecf190ecb
Author: Robert Muir <rmuir@apache.org>
Date: Thu May 5 17:03:02 2016 -0400
add fast-path for docvalues field loads
commit f8e38c0932fccc0cfa217516130ad61522e59fe5
Author: Robert Muir <rmuir@apache.org>
Date: Thu May 5 16:47:31 2016 -0400
Painless: add fielddata accessors (.value/.values/.distance()/etc)
e3ce6c9048