F# RFC FS-1046 - Wildcard self identifiers

The design suggestion Wildcard self identifiers has been marked "approved in principle". This RFC covers the detailed proposal for this suggestion.

Summary

Allow single underscore character as ignored self identifier.

Makes underscore semantic more consistent across the language.

Current workaround for ignoring self identifier in instance members is to use double underscores:

type C() = 
   member __.P = 1

Suggestion is to enhance parse to allow single underscore::

type C() = 
   member _.P = 1

Currently above results in syntax error:

Unexpected symbol '.' in member definition. Expected 'with', '=' or other token."

Additional complexity in parsing rules.

Continue using double underscore workaround.

No compatibility issues identified.

None.