コマンドに対して、そのエラボレータを教えてくれるコマンド

メタプロ本に載っている例: https://leanprover-community.github.io/lean4-metaprogramming-book/main/07_elaboration.html#mini-project

elab "#findCElab " c:command : command => do
  let macroRes ← liftMacroM <| expandMacroImpl? (←getEnv) c
  match macroRes with
  | some (name, _) => logInfo s!"Next step is a macro: {name.toString}"
  | none =>
    let kind := c.raw.getKind
    let elabs := commandElabAttribute.getEntries (←getEnv) kind
    match elabs with
    | [] => logInfo s!"There is no elaborators for your syntax, looks like its bad :("
    | _ => logInfo s!"Your syntax may be elaborated by: {elabs.map (fun el => el.declName.toString)}"

#findCElab def lala := 12 -- Your syntax may be elaborated by: [Lean.Elab.Command.elabDeclaration]
#findCElab abbrev lolo := 12 -- Your syntax may be elaborated by: [Lean.Elab.Command.elabDeclaration]
#findCElab #check foo -- even our own syntax!: Your syntax may be elaborated by: [mySpecialCheck, Lean.Elab.Command.elabCheck]
#findCElab open Hi -- Your syntax may be elaborated by: [Lean.Elab.Command.elabOpen]
#findCElab namespace Foo -- Your syntax may be elaborated by: [Lean.Elab.Command.elabNamespace]
#findCElab #findCElab open Bar -- even itself!: Your syntax may be elaborated by: [«_aux_lean_elaboration___elabRules_command#findCElab__1»]

Start with the linked Lean 4 metaprogramming-book mini-project and the shown #findCElab snippet. Trace expandMacroImpl?, commandElabAttribute, and getKind to understand the proposed lookup. Done means a command can report the macro or command elaborator for the supplied command syntax, including the examples shown in the issue.