Am Montag, dem 04.08.2025 um 18:37 -0400 schrieb Brandon Allbery:
And indeed, there is `Note [Uniques for wired-in prelude things and known tags]` in compiler/GHC/Builtin/Uniques.hs.
This doesn’t list which tags cause special compiler behavior, only which ones are used by GHC in general. Also, it is by no means clear that this list is comprehensive. It seems that its authors were partly even unsure about tag meaning: the entry for tag `a` has a question mark. Finally, this list leaves questions open. It sometimes only mentions compiler components to which certain tags are related but not for what kinds of uniques they are actually used (and not even whether said uniques are introduced or used by the mentioned compiler components). All the best, Wolfgang