content: {-# OPTIONS -fno-warn-incomplete-patterns #-}
  module GF.JavaScript.PrintJS (printTree, Doc, Print(..)) where
  
  -- pretty-printer generated by the BNF converter
  
  import GF.JavaScript.AbsJS
  import Data.Char
  
  -- the top-level printing method
  printTree :: Print a => a -> String
  printTree = render . prt 0
  
  type Doc = [ShowS] -> [ShowS]
  
  doc :: ShowS -> Doc
  doc = (:)
  
  render :: Doc -> String
  render d = rend 0 (map ($ "") $ d []) "" where
    rend i ss = case ss of
      t:ts | not (spaceAfter t) -> showString t . rend i ts
      t:ts@(t':_) | not (spaceBefore t') -> showString t . rend i ts
      t:ts -> space t . rend i ts
      []   -> id
  --new i   = showChar '\n' . replicateS (2*i) (showChar ' ') . dropWhile isSpace
    space t = showString t . (\s -> if null s then "" else (' ':s))
  
  spaceAfter :: String -> Bool
  spaceAfter = (`notElem` [".","(","[","{","\n"])
  
  spaceBefore :: String -> Bool
  spaceBefore = (`notElem` [",",".",":",";","(",")","[","]","{","}","\n"])
  
  parenth :: Doc -> Doc
  parenth ss = doc (showChar '(') . ss . doc (showChar ')')
  
  concatS :: [ShowS] -> ShowS
  concatS = foldr (.) id
  
  concatD :: [Doc] -> Doc
  concatD = foldr (.) id
  {-
  replicateS :: Int -> ShowS -> ShowS
  replicateS n f = concatS (replicate n f)
  -}
  -- the printer class does the job
  class Print a where
    prt :: Int -> a -> Doc
    prtList :: [a] -> Doc
    prtList = concatD . map (prt 0)
  
  instance Print a => Print [a] where
    prt _ = prtList
  
  instance Print Char where
    prt _ s = doc (showChar '\'' . mkEsc '\'' s . showChar '\'')
    prtList s = doc (showChar '"' . concatS (map (mkEsc '"') s) . showChar '"')
  
  mkEsc :: Char -> Char -> ShowS
  mkEsc q s = case s of
    _ | s == q -> showChar '\\' . showChar s
    '\\'-> showString "\\\\"
    '\n' -> showString "\\n"
    '\t' -> showString "\\t"
    _ -> showChar s
  
  prPrec :: Int -> Int -> Doc -> Doc
  prPrec i j = if j<i then parenth else id
  
  
  instance Print Int where
    prt _ x = doc (shows x)
  
  
  instance Print Double where
    prt _ x = doc (shows x)
  
  
  instance Print Ident where
    prt _ (Ident i) = doc (showString i)
    prtList es = case es of
     [] -> (concatD [])
     [x] -> (concatD [prt 0 x])
     x:xs -> (concatD [prt 0 x , doc (showString ",") , prt 0 xs])
  
  
  
  instance Print Program where
    prt i e = case e of
     Program elements -> prPrec i 0 (concatD [prt 0 elements])
  
  
  instance Print Element where
    prt i e = case e of
     FunDef id ids stmts -> prPrec i 0 (concatD [doc (showString "function") , prt 0 id , doc (showString "(") , prt 0 ids , doc (showString ")") , doc (showString "{") , prt 0 stmts , doc (showString "}")])
     ElStmt stmt -> prPrec i 0 (concatD [prt 0 stmt])
  
    prtList es = case es of
     [] -> (concatD [])
     x:xs -> (concatD [prt 0 x , doc (showString "\n"), prt 0 xs]) -- HACKED!
  
  instance Print Stmt where
    prt i e = case e of
     SCompound stmts -> prPrec i 0 (concatD [doc (showString "{") , prt 0 stmts , doc (showString "}")])
     SReturnVoid  -> prPrec i 0 (concatD [doc (showString "return") , doc (showString ";")])
     SReturn expr -> prPrec i 0 (concatD [doc (showString "return") , prt 0 expr , doc (showString ";")])
     SDeclOrExpr declorexpr -> prPrec i 0 (concatD [prt 0 declorexpr , doc (showString ";")])
  
    prtList es = case es of
     [] -> (concatD [])
     x:xs -> (concatD [prt 0 x , prt 0 xs])
  
  instance Print DeclOrExpr where
    prt i e = case e of
     Decl declvars -> prPrec i 0 (concatD [doc (showString "var") , prt 0 declvars])
     DExpr expr -> prPrec i 0 (concatD [prt 1 expr])
  
  
  instance Print DeclVar where
    prt i e = case e of
     DVar id -> prPrec i 0 (concatD [prt 0 id])
     DInit id expr -> prPrec i 0 (concatD [prt 0 id , doc (showString "=") , prt 0 expr])
  
    prtList es = case es of
     [] -> (concatD [])
     [x] -> (concatD [prt 0 x])
     x:xs -> (concatD [prt 0 x , doc (showString ",") , prt 0 xs])
  
  instance Print Expr where
    prt i e = case e of
     EAssign expr0 expr -> prPrec i 13 (concatD [prt 14 expr0 , doc (showString "=") , prt 13 expr])
     ENew id exprs -> prPrec i 14 (concatD [doc (showString "new") , prt 0 id , doc (showString "(") , prt 0 exprs , doc (showString ")")])
     EMember expr id -> prPrec i 15 (concatD [prt 15 expr , doc (showString ".") , prt 0 id])
     EIndex expr0 expr -> prPrec i 15 (concatD [prt 15 expr0 , doc (showString "[") , prt 0 expr , doc (showString "]")])
     ECall expr exprs -> prPrec i 15 (concatD [prt 15 expr , doc (showString "(") , prt 0 exprs , doc (showString ")")])
     EVar id -> prPrec i 16 (concatD [prt 0 id])
     EInt n -> prPrec i 16 (concatD [prt 0 n])
     EDbl d -> prPrec i 16 (concatD [prt 0 d])
     EStr str -> prPrec i 16 (concatD [prt 0 str])
     ETrue  -> prPrec i 16 (concatD [doc (showString "true")])
     EFalse  -> prPrec i 16 (concatD [doc (showString "false")])
     ENull  -> prPrec i 16 (concatD [doc (showString "null")])
     EThis  -> prPrec i 16 (concatD [doc (showString "this")])
     EFun ids stmts -> prPrec i 16 (concatD [doc (showString "function") , doc (showString "(") , prt 0 ids , doc (showString ")") , doc (showString "{") , prt 0 stmts , doc (showString "}")])
     EArray exprs -> prPrec i 16 (concatD [doc (showString "[") , prt 0 exprs , doc (showString "]")])
     EObj propertys -> prPrec i 16 (concatD [doc (showString "{") , prt 0 propertys , doc (showString "}")])
     ESeq exprs -> prPrec i 16 (concatD [doc (showString "(") , prt 0 exprs , doc (showString ")")])
  
    prtList es = case es of
     [] -> (concatD [])
     [x] -> (concatD [prt 0 x])
     x:xs -> (concatD [prt 0 x , doc (showString ",") , prt 0 xs])
  
  instance Print Property where
    prt i e = case e of
     Prop propertyname expr -> prPrec i 0 (concatD [prt 0 propertyname , doc (showString ":") , prt 0 expr])
  
    prtList es = case es of
     [] -> (concatD [])
     [x] -> (concatD [prt 0 x])
     x:xs -> (concatD [prt 0 x , doc (showString ",") , prt 0 xs])
  
  instance Print PropertyName where
    prt i e = case e of
     IdentPropName id -> prPrec i 0 (concatD [prt 0 id])
     StringPropName str -> prPrec i 0 (concatD [prt 0 str])
     IntPropName n -> prPrec i 0 (concatD [prt 0 n])
  