refactor(api): make typed dicts appear as types in the source code

problem: can we have Serde?
solution: we have Serde at home

This by itself is just a change of notation, that could be quickly
merged to avoid messy merge conflicts, but upcoming changes are planned:

- keysets no longer need to be defined in one single file. `keysets.h` is
  just the initial automatic conversion of the previous `keysets.lua`.
  keysets just used in a single api/{scope}.h can be moved to that file, later on.

- Typed dicts will have more specific types than Object. this will
  enable most of the existing manual typechecking boilerplate to be eliminated.
  We will need some annotation for missing value, i e a boolean will
  need to be represented as a TriState (none/false/true) in some cases.

- Eventually: optional parameters in form of a `Dict opts` final
  parameter will get added in some form to metadata. this will require
  a discussion/desicion about type forward compatibility.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/nvim/generators/c_grammar.lua b/src/nvim/generators/c_grammar.lua
index 3e89b60b4a..17a224fd22 100644
--- a/src/nvim/generators/c_grammar.lua
+++ b/src/nvim/generators/c_grammar.lua
@@ -55,5 +55,11 @@ local c_proto = Ct(
   fill * P(';')
   )
 
-local grammar = Ct((c_proto + c_comment + c_preproc + ws) ^ 1)
+local c_field = Ct(Cg(c_id, 'type') * ws * Cg(c_id, 'name') * fill * P(';') * fill)
+local c_keyset = Ct(
+   P('typedef') * ws * P('struct') * fill * P('{') * fill *
+   Cg(Ct(c_field ^ 1), 'fields') *
+   P('}') * fill * P('Dict') * fill * P('(') * Cg(c_id, 'keyset_name') * fill * P(')') * P(';'))
+
+local grammar = Ct((c_proto + c_comment + c_preproc + ws + c_keyset) ^ 1)
 return {grammar=grammar, typed_container=typed_container}