Converter: Remove unnecessary parentheses from function applications

Author: jgrosso

src/Axel/AST.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE FlexibleContexts #-}
@@ -45,6 +46,7 @@ import Control.Lens.TH (makeFieldsNoPrefix, makePrisms)
 import Control.Lens.Wrapped (_Wrapped)
 import Control.Monad ((>=>))
 
+import Data.Data (Data)
 import Data.Semigroup ((<>))
 
 class ToHaskell a where
@@ -58,15 +60,15 @@ data CaseBlock ann =
     , _expr :: Expression ann
     , _matches :: [(Expression ann, Expression ann)]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data FunctionApplication ann =
   FunctionApplication
     { _ann :: ann
     , _function :: Expression ann
     , _arguments :: [Expression ann]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data IfBlock ann =
   IfBlock
@@ -75,35 +77,35 @@ data IfBlock ann =
     , _ifTrue :: Expression ann
     , _ifFalse :: Expression ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data TopLevel ann =
   TopLevel
     { _ann :: ann
     , _statements :: [Statement ann]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data TypeDefinition ann
   = ProperType ann Identifier
   | TypeConstructor ann (FunctionApplication ann)
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data DataDeclaration ann =
   DataDeclaration
     { _ann :: ann
     , _typeDefinition :: TypeDefinition ann
     , _constructors :: [FunctionApplication ann]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data NewtypeDeclaration ann =
   NewtypeDeclaration
     { _ann :: ann
     , _typeDefinition :: TypeDefinition ann
     , _constructor :: FunctionApplication ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data FunctionDefinition ann =
   FunctionDefinition
@@ -113,55 +115,55 @@ data FunctionDefinition ann =
     , _body :: Expression ann
     , _whereBindings :: [FunctionDefinition ann]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data Import ann
   = ImportItem ann Identifier
   | ImportType ann Identifier [Identifier]
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data ImportSpecification ann
   = ImportAll ann
   | ImportOnly ann [Import ann]
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data Lambda ann =
   Lambda
     { _ann :: ann
     , _arguments :: [Expression ann]
     , _body :: Expression ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data LetBlock ann =
   LetBlock
     { _ann :: ann
     , _bindings :: [(Expression ann, Expression ann)]
     , _body :: Expression ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data MacroDefinition ann =
   MacroDefinition
     { _ann :: ann
     , _functionDefinition :: FunctionDefinition ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data MacroImport ann =
   MacroImport
     { _ann :: ann
     , _moduleName :: Identifier
     , _imports :: [Identifier]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data Pragma ann =
   Pragma
     { _ann :: ann
     , _pragmaSpecification :: String
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data QualifiedImport ann =
   QualifiedImport
@@ -170,29 +172,29 @@ data QualifiedImport ann =
     , _alias :: Identifier
     , _imports :: ImportSpecification ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data RecordDefinition ann =
   RecordDefinition
     { _ann :: ann
     , _bindings :: [(Identifier, Expression ann)]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data RecordType ann =
   RecordType
     { _ann :: ann
     , _fields :: [(Identifier, Expression ann)]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data RestrictedImport ann =
   RestrictedImport
     { _ann :: ann
     , _moduleName :: Identifier
     , _imports :: ImportSpecification ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data TypeclassDefinition ann =
   TypeclassDefinition
@@ -201,31 +203,31 @@ data TypeclassDefinition ann =
     , _constraints :: [Expression ann]
     , _signatures :: [TypeSignature ann]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data TypeclassInstance ann =
   TypeclassInstance
     { _ann :: ann
     , _instanceName :: Expression ann
     , _definitions :: [FunctionDefinition ann]
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data TypeSignature ann =
   TypeSignature
     { _ann :: ann
     , _name :: Identifier
     , _typeDefinition :: Expression ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data TypeSynonym ann =
   TypeSynonym
     { _ann :: ann
     , _alias :: Expression ann
     , _definition :: Expression ann
     }
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data Expression ann
   = ECaseBlock (CaseBlock ann)
@@ -239,13 +241,13 @@ data Expression ann
   | ERawExpression ann String
   | ERecordDefinition (RecordDefinition ann)
   | ERecordType (RecordType ann)
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data Literal ann
   = LChar ann Char
   | LInt ann Int
   | LString ann String
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 data Statement ann
   = STopLevel (TopLevel ann)
@@ -264,7 +266,7 @@ data Statement ann
   | STypeSignature (TypeSignature ann)
   | STypeSynonym (TypeSynonym ann)
   | SUnrestrictedImport ann Identifier
-  deriving (Eq, Functor, Show)
+  deriving (Data, Eq, Functor, Show)
 
 type Program ann = [Statement ann]
 

src/Axel/Haskell/Convert.hs

@@ -29,6 +29,8 @@ import Control.Category ((>>>))
 import Control.Lens.Extras (is)
 import Control.Lens.Operators ((%~), (^.))
 
+import Data.Data.Lens (biplate, uniplate)
+
 import qualified Polysemy as Sem
 import qualified Polysemy.Error as Sem
 
@@ -585,10 +587,21 @@ convertFile path newPath = do
        HSE.ParseFailed _ err -> Sem.throw $ ConvertError path err)
   putStrLn $ "Writing " <> newPath <> "..."
   let newContents =
-        unlines $ map toAxel $ groupFunctionDefinitions $ toStmts parsedModule
+        unlines $
+        map toAxel $
+        groupFunctionDefinitions $
+        flattenFunctionApplications $ toStmts parsedModule
   FS.writeFile newPath newContents
   pure newPath
 
+flattenFunctionApplications :: [AST.SMStatement] -> [AST.SMStatement]
+flattenFunctionApplications = map (biplate %~ (uniplate %~ handleExpr))
+  where
+    handleExpr :: AST.SMExpression -> AST.SMExpression
+    handleExpr (AST.EFunctionApplication (AST.FunctionApplication ann (AST.EFunctionApplication (AST.FunctionApplication _ fn args)) args')) =
+      AST.EFunctionApplication $ AST.FunctionApplication ann fn (args <> args')
+    handleExpr x = x
+
 groupFunctionDefinitions :: [AST.SMStatement] -> [SM.Expression]
 groupFunctionDefinitions =
   let findFnName (AST.SFunctionDefinition fnDef) = Just $ fnDef ^. AST.name