feat: include current file in default premise selector (#11168)

This PR changes the default library suggestions (e.g. for `grind
+suggestions` or `simp_all? +suggestions) to include the theorems from
the current file in addition to the output of Sine Qua Non.

src/Lean/LibrarySuggestions/Default.lean

@@ -11,15 +11,17 @@ import all Lean.LibrarySuggestions.SineQuaNon
 /-!
 # Default library suggestions engine
 
-This module sets the default library suggestions engine to Sine Qua Non.
+This module sets the default library suggestions engine to "Sine Qua Non",
+along with the theorems from the current file.
+.
 Any module that imports this (directly or transitively) will have library suggestions enabled.
 -/
 
 namespace Lean.LibrarySuggestions
 
-open Lean LibrarySuggestions SineQuaNon
-
--- Set the default library suggestions engine to Sine Qua Non
-set_library_suggestions Lean.LibrarySuggestions.sineQuaNonSelector
+-- Set the default library suggestions engine to
+-- a combination of "Sine Qua Non" and the theorems from the current file.
+-- For now we just intersperse the results, but in future we should re-rank them.
+set_library_suggestions open Lean.LibrarySuggestions in sineQuaNonSelector.intersperse currentFile
 
 end Lean.LibrarySuggestions

tests/lean/run/library_suggestions_persistent.lean

@@ -13,7 +13,11 @@ already be set from importing Lean.LibrarySuggestions (which imports Default).
 -/
 
 /--
-info: ✓ Selector found in imported state: `Lean.LibrarySuggestions.sineQuaNonSelector
+info: ✓ Selector found in imported state: (Term.open
+ "open"
+ (Command.openSimple [`Lean.LibrarySuggestions])
+ "in"
+ (Term.app `sineQuaNonSelector.intersperse [`currentFile]))
 ---
 info:   ✓ Successfully retrieved selector using getSelector!
 -/