[yang-doctors] Design pattern: Reusable types in type specific modules

[Ebben Aries <[e-mail]>]

YANG Doctors,

I'd like to understand if there has ever been motivation or guidance to
model authors to question if any types (typedefs, identities or even
groupings) they are bringing into domain specific work are to be
used/leveraged outside of the scope of their immediate model work and if
it's best to choose an alternate pattern to create domain specific types
modules.

Outside of the obvious reusable global type modules (ietf-inet-types,
ietf-yang-types, ietf-routing-types, etc..), there are many published
modules that bring in reusable common types along side data-trees,
notifications, rpcs, actions.

If another module wants to leverage any such types but the
implementation may not support all other constructs, this is where the
YANG library implement vs. import-only comes in however to a consumer,
this is often not well understood or mandated for workflows.  Another
solution here is to produce deviations which give another common
misperception and perceived abuse that support is advertised for a model
(or set of models due to sometimes vast dependency chains) then
completely negated since only a small subset of a type is the
dependency.

Where do we stand on this topic and have we been nudging any authors to
question if their types should indeed get pulled back into specific
domain/global types modules?

Thx

/ebben