basic python support working

README.md

@@ -145,7 +145,7 @@ Charlie
 We can describe the inputs using Templatespiler like so 
 ```js
 prices: list (sep-by " " [item : String, price : Float])
-orders: list (sep-by " " [
+orders: list ([
   name: String,
   order: list (sep-by " " [quantity : Integer, item : String])
 ])

templatespiler-bnf/src/Language/Templatespiler/Abs.hs

@@ -45,6 +45,7 @@ data BindingGroup' a = BindingGroup a [Binding' a]
 type BindingOrCombinator = BindingOrCombinator' BNFC'Position
 data BindingOrCombinator' a
     = NamedBinding a (Binding' a)
+    | GroupBinding a (BindingGroup' a)
     | ParenBinding a (Binding' a)
     | UnnamedBinding a (Combinator' a)
   deriving (C.Eq, C.Ord, C.Show, C.Read, C.Functor, C.Foldable, C.Traversable, C.Data, C.Typeable, C.Generic)
@@ -101,6 +102,7 @@ instance HasPosition BindingGroup where
 instance HasPosition BindingOrCombinator where
   hasPosition = \case
     NamedBinding p _ -> p
+    GroupBinding p _ -> p
     ParenBinding p _ -> p
     UnnamedBinding p _ -> p
 

templatespiler-bnf/src/Language/Templatespiler/Doc.txt

@@ -58,6 +58,7 @@ All other symbols are terminals.
   |  |  **|**  | **eps**
   |  |  **|**  | //Binding// //[Binding]//
   | //BindingOrCombinator// | -> | //Binding//
+  |  |  **|**  | //BindingGroup//
   |  |  **|**  | ``(`` //Binding// ``)``
   |  |  **|**  | //Combinator//
   | //Combinator// | -> | ``(`` //Combinator// ``)``

templatespiler-bnf/src/Language/Templatespiler/Par.y

@@ -77,6 +77,7 @@ ListBinding
 BindingOrCombinator :: { (Language.Templatespiler.Abs.BNFC'Position, Language.Templatespiler.Abs.BindingOrCombinator) }
 BindingOrCombinator
   : Binding { (fst $1, Language.Templatespiler.Abs.NamedBinding (fst $1) (snd $1)) }
+  | BindingGroup { (fst $1, Language.Templatespiler.Abs.GroupBinding (fst $1) (snd $1)) }
   | '(' Binding ')' { (uncurry Language.Templatespiler.Abs.BNFC'Position (tokenLineCol $1), Language.Templatespiler.Abs.ParenBinding (uncurry Language.Templatespiler.Abs.BNFC'Position (tokenLineCol $1)) (snd $2)) }
   | Combinator { (fst $1, Language.Templatespiler.Abs.UnnamedBinding (fst $1) (snd $1)) }
 

templatespiler-bnf/src/Language/Templatespiler/Print.hs

@@ -168,6 +168,7 @@ instance Print [Language.Templatespiler.Abs.Binding' a] where
 instance Print (Language.Templatespiler.Abs.BindingOrCombinator' a) where
   prt i = \case
     Language.Templatespiler.Abs.NamedBinding _ binding -> prPrec i 0 (concatD [prt 0 binding])
+    Language.Templatespiler.Abs.GroupBinding _ bindinggroup -> prPrec i 0 (concatD [prt 0 bindinggroup])
     Language.Templatespiler.Abs.ParenBinding _ binding -> prPrec i 0 (concatD [doc (showString "("), prt 0 binding, doc (showString ")")])
     Language.Templatespiler.Abs.UnnamedBinding _ combinator -> prPrec i 0 (concatD [prt 0 combinator])
 

templatespiler-bnf/src/Language/Templatespiler/Skel.hs

@@ -39,6 +39,7 @@ transBindingGroup x = case x of
 transBindingOrCombinator :: Show a => Language.Templatespiler.Abs.BindingOrCombinator' a -> Result
 transBindingOrCombinator x = case x of
   Language.Templatespiler.Abs.NamedBinding _ binding -> failure x
+  Language.Templatespiler.Abs.GroupBinding _ bindinggroup -> failure x
   Language.Templatespiler.Abs.ParenBinding _ binding -> failure x
   Language.Templatespiler.Abs.UnnamedBinding _ combinator -> failure x
 

templatespiler-converter/src/Main.hs

@@ -4,18 +4,23 @@ import Control.Monad.Writer (execWriter, runWriter)
 import Language.Templatespiler.Par
 import Main.Utf8 qualified as Utf8
 import Prettyprinter.Render.Text
-import Shower (shower)
+import Shower (printer, shower)
+import Templatespiler.Convert (toImperative)
 import Templatespiler.Convert.Python (convertToPython)
 
 main :: IO ()
 main = do
   Utf8.withUtf8 $ do
-    file <- readFileText "./test.tmpspl"
+    file <- readFileText "../test.tmpspl"
     let tokens = myLexer file
     case pBindingList tokens of
       Left err -> putStrLn $ shower err
       Right bs -> do
-        putStrLn "Parsed:"
-        putStrLn $ shower bs
-        putDoc $ execWriter $ convertToPython bs
+        -- putStrLn "Parsed:"
+        -- putStrLn $ shower bs
+        putStrLn ""
+        let imp = toImperative bs
+        printer imp
+        putStrLn ""
+        putDoc $ execWriter $ convertToPython imp
     putStrLn ""

templatespiler-converter/src/Templatespiler/Convert.hs

@@ -2,7 +2,9 @@ module Templatespiler.Convert where
 
 import Control.Monad.Writer
 import Language.Templatespiler.Abs
-import Templatespiler.IR.Imperative as Imp
+import Shower (shower)
+import Templatespiler.IR.Imperative (withSuffix)
+import Templatespiler.IR.Imperative qualified as Imp
 
 toImperative :: BindingList -> [Imp.Statement]
 toImperative (BindingList _ bs) = foldMap toImperativeBinding bs
@@ -11,14 +13,43 @@ toImperative (BindingList _ bs) = foldMap toImperativeBinding bs
     toImperativeBinding (Binding _ n t) = execWriter $ do
       case t of
         StringType _ -> do
-          tell [Decl n (Read n [ReadString])]
+          tell [Imp.Assign (toVarName n) Imp.StringType (Imp.ReadAtom Imp.ReadString)]
         IntegerType _ -> do
-          tell [Decl n (Read n [ReadInt])]
+          tell [Imp.Assign (toVarName n) Imp.IntType (Imp.ReadAtom Imp.ReadInt)]
         FloatType _ -> do
-          tell [Decl n (Read n [ReadFloat])]
+          tell [Imp.Assign (toVarName n) Imp.FloatType (Imp.ReadAtom Imp.ReadFloat)]
         CombinatorType _ combin -> do
           toImperativeCombinator n combin
 
-    toImperativeCombinator :: Ident -> Combinator' BNFC'Position -> Writer [Statement] ()
-    toImperativeCombinator n (ListCombinator b) = do
-      tell [Decl ()]
+    toImperativeBindingOrCombinator :: BindingOrCombinator -> Writer [Imp.Statement] ()
+    toImperativeBindingOrCombinator (NamedBinding _ b) = tell $ toImperativeBinding b
+    toImperativeBindingOrCombinator (ParenBinding _ b) = tell $ toImperativeBinding b
+    toImperativeBindingOrCombinator (UnnamedBinding _ c) = toImperativeCombinator (Ident "unnamed") c
+    toImperativeBindingOrCombinator (GroupBinding _ (BindingGroup _ bs)) = do
+      tell $ foldMap toImperativeBinding bs
+
+    toImperativeCombinator :: Ident -> Combinator' BNFC'Position -> Writer [Imp.Statement] ()
+    toImperativeCombinator n (ParenCombinator _ c) = toImperativeCombinator n c
+    toImperativeCombinator n (SepByCombinator _ sep c) = do
+      let (BindingGroup _ bs) = c
+      let toReadAssign (Binding _ n t) =
+            ( toVarName n
+            , case t of
+                StringType _ -> Imp.ReadString
+                IntegerType _ -> Imp.ReadInt
+                FloatType _ -> Imp.ReadFloat
+                CombinatorType _ c -> error ("CombinatorType in toReadAssign: " <> toText (shower c))
+            )
+      tell [Imp.MultiReadAssign (toText sep) (toReadAssign <$> bs)]
+    toImperativeCombinator n (ListCombinator _ b) = do
+      let lenName = toVarName n `withSuffix` "len"
+      tell [Imp.Assign lenName Imp.IntType (Imp.ReadAtom Imp.ReadInt)]
+      tell [Imp.Decl (toVarName n) (Imp.ArrayType Imp.UnknownType)]
+      let (_, b') = runWriter $ toImperativeBindingOrCombinator b
+      tell [Imp.For (toVarName "i") (Imp.ConstInt 0) (Imp.Var lenName) b']
+
+toVarName :: Ident -> Imp.VarName
+toVarName (Ident n) = toVarName' n
+
+toVarName' :: (ToText s) => s -> Imp.VarName
+toVarName' s = Imp.VarName (toText s :| [])

templatespiler-converter/src/Templatespiler/Convert/Common.hs

@@ -1,11 +1,13 @@
-module Templatespiler.Convert.Common (tell, identToText, identToDoc, indented, indentDepth, DocBuilder) where
+module Templatespiler.Convert.Common (tell, identToText, identToDoc, indented, indentDepth, Doc', DocBuilder, write) where
 
 import Control.Monad.Writer
 import Language.Templatespiler.Abs (Ident (..))
 import Prettyprinter (Doc, Pretty (pretty), indent)
 
 type Ann = ()
 
+type Doc' = Doc Ann
+
 type DocBuilder a = Writer (Doc Ann) a
 
 identToText :: Ident -> Text
@@ -23,3 +25,6 @@ indented b = do
   let (d, a) = runWriter b
   tell (indent indentDepth a)
   pure d
+
+write :: Doc Ann -> DocBuilder ()
+write = tell

templatespiler-converter/src/Templatespiler/Convert/Python.hs

@@ -1,48 +1,75 @@
 module Templatespiler.Convert.Python where
 
 import Control.Monad (foldM)
-import Language.Templatespiler.Abs as Abs
 import Prettyprinter (Pretty (pretty))
 import Templatespiler.Convert.Common
+import Templatespiler.IR.Imperative as IR
 
-convertToPython :: BindingList -> DocBuilder ()
-convertToPython (BindingList _ bindings) = foldM (\_ b -> writeBinding b) () bindings
-
-writeBinding :: Binding -> DocBuilder ()
-writeBinding (Binding _ n t) = do
-  tell (identToDoc n)
-  tell " = "
-  writeType t
-  tell "\n"
-
-writeType :: Abs.Type -> DocBuilder ()
-writeType (Abs.StringType _) = tell "input()"
-writeType (Abs.IntegerType _) = tell "int(input())"
-writeType (Abs.FloatType _) = tell "float(input())"
-writeType (Abs.CombinatorType _ combin) = writeCombinator combin
-
-writeCombinator :: Combinator -> DocBuilder ()
-writeCombinator (ParenCombinator _ c) = writeCombinator c
-writeCombinator (ArrayCombinator _ len c) = do
-  tell "for i"
-  tell " in range(0, "
-
-  writeVarOrConstInt len
-  tell "):\n"
-  indented $ do
-    writeBindingOrCombinator c
-writeCombinator (ListCombinator _ c) = do
-  tell "length = int(input())\n"
-  tell "for i in range(0, length):\n"
-  indented $ do
-    writeBindingOrCombinator c
-writeCombinator other = error ("writeCombinator: " <> show other)
-
-writeBindingOrCombinator :: BindingOrCombinator -> DocBuilder ()
-writeBindingOrCombinator (NamedBinding _ b) = writeBinding b
-writeBindingOrCombinator (ParenBinding _ b) = writeBinding b
-writeBindingOrCombinator (UnnamedBinding _ c) = writeCombinator c
-
-writeVarOrConstInt :: VarOrConstInt -> DocBuilder ()
-writeVarOrConstInt (ConstInt _ v) = tell (pretty v)
-writeVarOrConstInt (ConstVar _ v) = tell (identToDoc v)
+convertToPython :: [Statement] -> DocBuilder ()
+convertToPython = foldM (\_ b -> writeBinding b) ()
+
+writeBinding :: Statement -> DocBuilder ()
+writeBinding (Decl name t) = do
+  writeVarName name
+  write " = "
+  writeDefaultVarType t
+  write "\n"
+writeBinding (Assign name t val) = do
+  writeVarName name
+  write " = "
+  writeExpr val
+  write "\n"
+writeBinding (For name start end body) = do
+  write "for "
+  writeVarName name
+  write " in range("
+  writeExpr start
+  write ", "
+  writeExpr end
+  write "):\n"
+  indented $ mapM_ writeBinding body
+  write "\n"
+writeBinding (MultiReadAssign sep parts) = do
+  write "line = input()\n"
+  write "parts = line.split("
+  write (pretty $ toPyStrLit sep)
+  write ")\n"
+  mapM_ writeMultiReadAssignPart (zip [0 ..] parts)
+  where
+    writeMultiReadAssignPart :: (Int, (VarName, ReadType)) -> DocBuilder ()
+    writeMultiReadAssignPart (idx, (name, rt)) = do
+      writeVarName name
+      write " = "
+      writeReadAtom ("parts[" <> pretty idx <> "]") rt
+      write "\n"
+
+writeExpr :: Expr -> DocBuilder ()
+writeExpr (ConstInt i) = write (pretty i)
+writeExpr (Var name) = writeVarName name
+writeExpr (ReadAtom rt) = writeReadAtom "input()" rt
+
+toPyStrLit :: Text -> Text
+toPyStrLit s = "'" <> s <> "'"
+
+writeReadAtom :: Doc' -> ReadType -> DocBuilder ()
+writeReadAtom source ReadInt = write ("int(" <> source <> ")")
+writeReadAtom source ReadFloat = write ("float(" <> source <> ")")
+writeReadAtom source ReadString = write source
+
+writeDefaultVarType :: VarType -> DocBuilder ()
+writeDefaultVarType IntType = write "0"
+writeDefaultVarType FloatType = write "0.0"
+writeDefaultVarType StringType = write "''"
+writeDefaultVarType (ArrayType t) = do
+  write "[]"
+
+writeVarName :: VarName -> DocBuilder ()
+writeVarName (VarName ns) = writeVarName' (toList ns)
+  where
+    writeVarName' :: [Text] -> DocBuilder ()
+    writeVarName' [] = pass
+    writeVarName' [n] = write (pretty n)
+    writeVarName' (n : ns) = do
+      write (pretty n)
+      write "_"
+      writeVarName' ns

templatespiler-converter/src/Templatespiler/IR/Imperative.hs

@@ -7,26 +7,47 @@ module Templatespiler.IR.Imperative where
 newtype VarName
   = VarName
       (NonEmpty Text)
+  deriving (Show)
 
 withSuffix :: VarName -> Text -> VarName
 withSuffix (VarName (n :| ns)) suffix = VarName (n :| (ns <> [suffix]))
 
 data Statement
-  = Decl VarName Expr
+  = -- | Variable declaration. This may be a C-style declaration (@int x@) or an assignment (@x = 0@) depending on the target language.
+    Decl
+      VarName
+      -- ^ The variable name
+      VarType
+      -- ^ The type
+  | Assign VarName VarType Expr
+  | MultiReadAssign
+      Text -- Separator
+      [(VarName, ReadType)]
   | For
       VarName -- variable name
       Expr -- start
       Expr -- end
       [Statement] -- body
+  deriving (Show)
+
+data VarType
+  = IntType
+  | FloatType
+  | StringType
+  | ArrayType VarType
+  | UnknownType
+  deriving (Show)
 
 data Expr
   = ConstInt Int
   | Var VarName
-  | Read VarName [ReadType]
+  | ReadAtom ReadType
   | TupleOrStruct (Maybe VarName) (NonEmpty Expr)
+  deriving (Show)
 
 data ReadType
   = ReadInt
   | ReadFloat
   | ReadString
   | ReadConst Text
+  deriving (Show)

templatespiler.cf

@@ -13,6 +13,7 @@ BindingGroup. BindingGroup ::= "[" [Binding] "]" ;
 separator Binding "," ;
 
 NamedBinding. BindingOrCombinator ::= Binding;
+GroupBinding. BindingOrCombinator ::= BindingGroup;
 ParenBinding . BindingOrCombinator ::= "(" Binding ")" ;
 UnnamedBinding. BindingOrCombinator ::= Combinator;
 

test.tmpspl

@@ -1,5 +1,5 @@
 prices: list (sep-by " " [item : String, price : Float])
-orders: list (sep-by " " [
+orders: list [
   name: String,
   order: list (sep-by " " [quantity : Integer, item : String])
-])
+]