1 files changed, 133 insertions, 0 deletions
diff --git a/src/GF/JavaScript/PrintJS.hs b/src/GF/JavaScript/PrintJS.hs
new file mode 100644
index 000000000..852cdb2e9
--- /dev/null
+++ b/src/GF/JavaScript/PrintJS.hs
@@ -0,0 +1,133 @@
+{-# OPTIONS -fno-warn-incomplete-patterns #-}
+module GF.JavaScript.PrintJS where
+
+-- pretty-printer generated by the BNF converter
+
+import GF.JavaScript.AbsJS
+import 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
+    "["      :ts -> showChar '[' . rend i ts
+    "("      :ts -> showChar '(' . rend i ts
+    "{"      :ts -> showChar '{' . new (i+1) . rend (i+1) ts
+    "}" : ";":ts -> new (i-1) . space "}" . showChar ';' . new (i-1) . rend (i-1) ts
+    "}"      :ts -> new (i-1) . showChar '}' . new (i-1) . rend (i-1) ts
+    ";"      :ts -> showChar ';' . new i . rend i ts
+    t  : "," :ts -> showString t . space "," . rend i ts
+    t  : ")" :ts -> showString t . showChar ')' . rend i ts
+    t  : "]" :ts -> showString t . showChar ']' . 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))
+
+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 Integer 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 , prt 0 xs])
+
+instance Print Stmt where
+  prt i e = case e of
+   Compound stmts -> prPrec i 0 (concatD [doc (showString "{") , prt 0 stmts , doc (showString "}")])
+   ReturnVoid  -> prPrec i 0 (concatD [doc (showString "return") , doc (showString ";")])
+   Return expr -> prPrec i 0 (concatD [doc (showString "return") , prt 0 expr , doc (showString ";")])
+
+  prtList es = case es of
+   [] -> (concatD [])
+   x:xs -> (concatD [prt 0 x , prt 0 xs])
+
+instance Print Expr where
+  prt i e = case e of
+   ENew id exprs -> prPrec i 14 (concatD [doc (showString "new") , prt 0 id , doc (showString "(") , prt 0 exprs , doc (showString ")")])
+   EMember expr0 expr -> prPrec i 15 (concatD [prt 15 expr0 , doc (showString ".") , prt 16 expr])
+   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")])
+
+  prtList es = case es of
+   [] -> (concatD [])
+   [x] -> (concatD [prt 0 x])
+   x:xs -> (concatD [prt 0 x , doc (showString ",") , prt 0 xs])
+
+