add --yes option for --delete

eg on Stackage delete-work maybe requires 1000s of prompts

src/GHC.hs

@@ -68,9 +68,9 @@ removeGhcVersionInstallation deletion ghcver msystem = do
         if isMajorVersion ghcver
         then do
           yes <-
-            if isDelete deletion then
-              yesNo $ "Delete all stack ghc" +-+ showVersion ghcver +-+ "installations"
-              else return True
+            if deletePrompt deletion
+            then yesNo $ "Delete all stack ghc" +-+ showVersion ghcver +-+ "installations"
+            else return True
           when yes $
             mapM_ (doRemoveGhcVersion deletion) gs
         else error' "more than one match found!!"

src/GHCTarball.hs

@@ -63,9 +63,9 @@ removeGhcVersionTarball deletion ghcver msystem = do
         if isMajorVersion ghcver
         then do
           yes <-
-            if isDelete deletion then
-              yesNo $ "Delete all stack ghc" +-+ showVersion ghcver +-+ "tarballs"
-              else return True
+            if deletePrompt deletion
+            then yesNo $ "Delete all stack ghc" +-+ showVersion ghcver +-+ "tarballs"
+            else return True
           when yes $
             mapM_ (doRemoveGhcTarballVersion deletion) gs
         else error' "more than one match found!!"

src/Main.hs

@@ -82,7 +82,10 @@ main = do
       flagWith' Tarballs 'T' "tarballs" ("Act on" +-+ stackroot </> "programs/ tarballs") <|>
       flagWith Default Global 'G' "global" ("Act on both" +-+ stackroot </> "{programs,snapshots}/ [default outside project dir]")
 
-    deleteOpt = flagWith Dryrun Delete 'd' "delete" "Do deletion [default is dryrun]"
+    deleteOpt =
+      (flagWith' Delete 'd' "delete" "Do deletion [default is dryrun]" <*>
+      switchWith 'y' "yes" "Assume yes for all prompts") <|>
+      pure Dryrun
 
     recursionOpt =
       optional (

src/Snapshots.hs

@@ -111,7 +111,7 @@ cleanGhcSnapshots deletion cwd ghcver platform = do
     unless (null ghcs) $
       putStrLn (platform ++ ":")
     yes <-
-      if isMajorVersion ghcver && isDelete deletion
+      if isMajorVersion ghcver && deletePrompt deletion
       then yesNo $ "Delete all" +-+ showVersion ghcver +-+ "builds"
       else return True
     when yes $
@@ -181,7 +181,7 @@ printTotalGhcSize versnaps = do
 removeStackWork :: Deletion -> IO ()
 removeStackWork deletion = do
   yes <-
-    if isDelete deletion
+    if deletePrompt deletion
     then yesNo "Delete .stack-work"
     else return True
   when yes $

src/Types.hs

@@ -1,11 +1,16 @@
 module Types (
   Deletion (..),
-  isDelete
+  isDelete,
+  deletePrompt
   )
 where
 
-data Deletion = Dryrun | Delete
-  deriving Eq
+data Deletion = Dryrun | Delete Bool
 
 isDelete :: Deletion -> Bool
-isDelete = (== Delete)
+isDelete (Delete _) = True
+isDelete Dryrun = False
+
+deletePrompt :: Deletion -> Bool
+deletePrompt (Delete False) = True
+deletePrompt _ = False