[ refactor ] lift partitionEithers to toplevel

src/Idris/ModTree.idr

@@ -23,6 +23,8 @@ import Data.StringMap
 import System.Directory
 import System.File
 
+import Utils.Either
+
 %default covering
 
 record ModTree where
@@ -162,7 +164,7 @@ buildMod loc num len mod
         -- We'd expect any errors in nsToPath to have been caught by now
         -- since the imports have been built! But we still have to check.
         depFilesE <- traverse (nsToPath loc) (imports mod)
-        let (ferrs, depFiles) = getEithers depFilesE
+        let (ferrs, depFiles) = partitionEithers depFilesE
         ttcTime <- catch (do t <- fnameModified mttc
                              pure (Just t))
                          (\err => pure Nothing)
@@ -193,16 +195,6 @@ buildMod loc num len mod
            else do emitWarnings
                    traverse_ emitError ferrs
                    pure ferrs
-  where
-    getEithers : List (Either a b) -> (List a, List b)
-    getEithers [] = ([], [])
-    getEithers (Left x :: es)
-        = let (ls, rs) = getEithers es in
-              (x :: ls, rs)
-    getEithers (Right y :: es)
-        = let (ls, rs) = getEithers es in
-              (ls, y :: rs)
-
 
 buildMods : {auto c : Ref Ctxt Defs} ->
             {auto s : Ref Syn SyntaxInfo} ->

src/Utils/Either.idr

@@ -5,3 +5,13 @@ module Utils.Either
 export
 mapError : (a -> c) -> Either a b -> Either c b
 mapError f e = either (Left . f) (Right . id) e
+
+export
+partitionEithers : List (Either a b) -> (List a, List b)
+partitionEithers [] = ([], [])
+partitionEithers (Left x :: es)
+        = let (ls, rs) = partitionEithers es in
+              (x :: ls, rs)
+partitionEithers (Right y :: es)
+        = let (ls, rs) = partitionEithers es in
+              (ls, y :: rs)