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| author | Alec Theriault <alec.theriault@gmail.com> | 2020-03-28 12:04:16 -0400 |
|---|---|---|
| committer | Alec Theriault <alec.theriault@gmail.com> | 2020-03-28 13:36:25 -0400 |
| commit | 730a2163245cf7aaf389458113e6fa338eca7865 (patch) | |
| tree | 8822a3ed69620eb56e01f185d46787d280f51032 /haddock-api/src/Haddock/GhcUtils.hs | |
| parent | e68cc0f05c102193660466d611640aec922bc9a9 (diff) | |
Use TTG empty extensions to remove some `error`'s
None of these error cases should ever have been reachable, so this is
just a matter of leveraging the type system to assert this.
* Use the `NoExtCon` and `noExtCon` to handle case matches for no
extension constructors, instead of throwing an `error`.
* Use the extension field of `HsSpliceTy` to ensure that this variant
of `HsType` cannot exist in an `HsType DocNameI`.
Diffstat (limited to 'haddock-api/src/Haddock/GhcUtils.hs')
| -rw-r--r-- | haddock-api/src/Haddock/GhcUtils.hs | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/haddock-api/src/Haddock/GhcUtils.hs b/haddock-api/src/Haddock/GhcUtils.hs index 77d6ec39..f600997a 100644 --- a/haddock-api/src/Haddock/GhcUtils.hs +++ b/haddock-api/src/Haddock/GhcUtils.hs @@ -165,18 +165,17 @@ nubByName f ns = go emptyNameSet ns where y = f x + -- --------------------------------------------------------------------- -- These functions are duplicated from the GHC API, as they must be -- instantiated at DocNameI instead of (GhcPass _). -hsTyVarNameI :: HsTyVarBndr DocNameI -> DocName -hsTyVarNameI (UserTyVar _ (L _ n)) = n -hsTyVarNameI (KindedTyVar _ (L _ n) _) = n -hsTyVarNameI (XTyVarBndr nec) = noExtCon nec - -hsLTyVarNameI :: LHsTyVarBndr DocNameI -> DocName -hsLTyVarNameI = hsTyVarNameI . unLoc +-- | Like 'hsTyVarName' from GHC API, but not instantiated at (GhcPass _) +hsTyVarBndrName :: (XXTyVarBndr n ~ NoExtCon) => HsTyVarBndr n -> IdP n +hsTyVarBndrName (UserTyVar _ name) = unLoc name +hsTyVarBndrName (KindedTyVar _ (L _ name) _) = name +hsTyVarBndrName (XTyVarBndr nec) = noExtCon nec getConNamesI :: ConDecl DocNameI -> [Located DocName] getConNamesI ConDeclH98 {con_name = name} = [name] @@ -311,7 +310,7 @@ restrictDataDefn names defn@(HsDataDefn { dd_ND = new_or_data, dd_cons = cons }) [] -> defn { dd_ND = DataType, dd_cons = [] } [con] -> defn { dd_cons = [con] } _ -> error "Should not happen" -restrictDataDefn _ (XHsDataDefn _) = error "restrictDataDefn" +restrictDataDefn _ (XHsDataDefn nec) = noExtCon nec restrictCons :: [Name] -> [LConDecl GhcRn] -> [LConDecl GhcRn] restrictCons names decls = [ L p d | L p (Just d) <- map (fmap keep) decls ] |