[yang-doctors] YANG dialects?

[Andy Bierman <[e-mail]>]

Hi,

I noticed in the help output for pyang 2.1:

  --mef                 Validate the module(s) according to MEF rules.
  --ieee                Validate the module(s) according to IEEE rules.
  --ietf                Validate the module(s) according to IETF rules.
  --bbf                 Validate the module(s) according to BBF rules.
  --lint                Validate the module(s) according to RFC 8407rules.


I guess --openconfig is missing (since they have their own rules for YANG
as well)

I hope these different rules are for style only, and not redefining YANG.
I suspect it is more than that.

I am aware of at least 3 openconfig issues that do not follow YANG rules:
   - repurposing pattern-stmt to use a different syntax
   - referencing config=false nodes from config=true context node for
when-stmts
   - use of identity strings without prefixes in XPath, where the default
module does
     not contain the identity (it is in an imported module instead)

Should we just continue hacking the tools in proprietary ways to deal with
the inconsistencies? Are there any issues the IETF (or YANG doctors)
could or should address?

For starters, can somebody explain the different rules pyang is checking
here?


Andy