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{-# 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 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 . showString "." . rend i ts
t : ")" :ts -> showString t . showChar ')' . 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
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 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])
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