ogma-core: Replace uses of awhen with uses of for_. Refs #150.

The dependency on IfElse is quite unnecessary: it seems like the only
function we use from that library is awhen :: Monad m => Maybe a -> (a
-> m ()) -> m (), which is a type-specialized version of
Data.Foldable.for_.. Since the latter is in base, we can simplify Ogma
by removing the dependency on IfElse.

This commit replaces uses of awhen with uses of for_.

ogma-core/src/Command/FRETComponentSpec2Copilot.hs

@@ -41,9 +41,9 @@ module Command.FRETComponentSpec2Copilot
   where
 
 -- External imports
-import Control.Monad.IfElse ( awhen )
 import Data.Aeson           ( eitherDecode, decode )
 import Data.ByteString.Lazy (fromStrict)
+import Data.Foldable        (for_)
 
 -- External imports: auxiliary
 import Data.ByteString.Extra as B ( safeReadFile )
@@ -91,7 +91,7 @@ fretComponentSpec2Copilot fp options = do
   let (mOutput, result) =
         fretComponentSpec2CopilotResult options fp copilot
 
-  awhen mOutput putStrLn
+  for_ mOutput putStrLn
   return result
 
 -- | Print the contents of a Copilot module that implements the Past-time TL

ogma-core/src/Command/FRETReqsDB2Copilot.hs

@@ -39,9 +39,9 @@ module Command.FRETReqsDB2Copilot
   where
 
 -- External imports
-import Control.Monad.IfElse ( awhen )
-import Data.Aeson           ( eitherDecode )
-import Data.List            ( nub, (\\) )
+import Data.Aeson    (eitherDecode)
+import Data.Foldable (for_)
+import Data.List     (nub, (\\))
 
 -- External imports: auxiliary
 import Data.ByteString.Extra as B ( safeReadFile )
@@ -88,7 +88,7 @@ fretReqsDB2Copilot fp options = do
   let (mOutput, result) =
         fretReqsDB2CopilotResult options fp copilot
 
-  awhen mOutput putStrLn
+  for_ mOutput putStrLn
   return result
 
 -- | Print the contents of a Copilot module that implements the Past-time TL