module Language.Lua.PrettyPrinter (pprint, LPretty) where
import Prelude hiding (EQ, GT, LT)
import Text.PrettyPrint.Leijen hiding ((<$>))
import Language.Lua.Types
intercalate :: Doc -> [Doc] -> Doc
intercalate s elems = sep (punctuate s elems)
infixr 5 <$>
(<$>) :: Doc -> Doc -> Doc
x <$> y | isEmpty y = x
| otherwise = x <> line <> y
class LPretty a where
pprint :: a -> Doc
instance LPretty [Char] where
pprint s = text s
instance LPretty Bool where
pprint True = text "true"
pprint False = text "false"
instance LPretty Exp where
pprint Nil = text "nil"
pprint (Bool s) = pprint s
pprint (Number n) = text n
pprint (String s) = dquotes (text s)
pprint Vararg = text "..."
pprint (EFunDef f) = pprint f
pprint (PrefixExp pe) = pprint pe
pprint (TableConst t) = pprint t
pprint (Binop op e1 e2) = pprint e1 <+> pprint op <+> pprint e2
pprint (Unop op e) = pprint op <> pprint e
instance LPretty Var where
pprint (Name n) = text n
pprint (Select pe e) = pprint pe <> brackets (pprint e)
pprint (SelectName pe name) = group (pprint pe <$$> (char '.' <> pprint name))
instance LPretty Binop where
pprint Add = char '+'
pprint Sub = char '-'
pprint Mul = char '*'
pprint Div = char '/'
pprint Exp = char '^'
pprint Mod = char '%'
pprint Concat = text ".."
pprint LT = char '<'
pprint LTE = text "<="
pprint GT = char '>'
pprint GTE = text ">="
pprint EQ = text "=="
pprint NEQ = text "~="
pprint And = text "and"
pprint Or = text "or"
instance LPretty Unop where
pprint Neg = char '-'
pprint Not = text "not "
pprint Len = char '#'
instance LPretty PrefixExp where
pprint (PEVar var) = pprint var
pprint (PEFunCall funcall) = pprint funcall
pprint (Paren e) = parens (pprint e)
instance LPretty Table where
pprint (Table fields) = braces (nest 4 (cat (punctuate comma (map pprint fields))))
instance LPretty TableField where
pprint (ExpField e1 e2) = brackets (pprint e1) <+> equals <+> pprint e2
pprint (NamedField name e) = pprint name <+> equals <+> pprint e
pprint (Field e) = pprint e
instance LPretty Block where
pprint (Block stats ret)
= case stats of
[] -> ret'
_ -> (foldr (<$>) empty (map pprint stats)) <$> ret'
where ret' = case ret of
Nothing -> empty
Just e -> nest 2 (text "return" </> (intercalate comma (map pprint e)))
instance LPretty FunName where
pprint (FunName name s methods) = text name <> s' <> (intercalate colon (map pprint methods))
where s' = case s of
Nothing -> empty
Just s' -> char '.' <> text s'
instance LPretty FunDef where
pprint (FunDef body) = pprint body
instance LPretty FunBody where
pprint funbody = pprintFunction Nothing funbody
pprintFunction :: Maybe Doc -> FunBody -> Doc
pprintFunction funname (FunBody args vararg block)
= group (nest 4 (funhead <$> funbody) <$> end)
where funhead = case funname of
Nothing -> nest 2 (text "function" </> args')
Just n -> nest 2 (text "function" </> n </> args')
args' = parens (align (cat (punctuate (comma <> space)
(map pprint (args ++ if vararg then ["..."] else [])))))
funbody = pprint block
end = text "end"
instance LPretty FunCall where
pprint (NormalFunCall pe arg) = group (nest 4 (pprint pe <$$> pprint arg))
pprint (MethodCall pe method arg) = group (nest 4 (pprint pe <$$> (colon <> text method) <$$> pprint arg))
instance LPretty FunArg where
pprint (Args exps) = parens (nest 4 (cat (punctuate (comma <> space) (map pprint exps))))
pprint (TableArg t) = pprint t
pprint (StringArg s) = dquotes (text s)
instance LPretty Stat where
pprint (Assign names vals)
= (intercalate comma (map pprint names))
<+> equals
<+> (intercalate comma (map pprint vals))
pprint (FunCall funcall) = pprint funcall
pprint (Label name) = text "::" <> text name <> text "::"
pprint Break = text "break"
pprint (Goto name) = text "goto" <+> text name
pprint (Do block) = group (nest 4 (text "do" <$> pprint block) <$> text "end")
pprint (While guard e)
= (nest 4 (text "while" <+> pprint guard <+> text "do"
</> indent 4 (pprint e)))
</> text "end"
pprint (Repeat block guard)
= nest 4 (text "repeat" </> pprint block) </> (nest 4 (text "until" </> pprint guard))
pprint (If cases elsePart) = group (printIf cases elsePart)
where printIf ((guard, block):xs) e
= group (nest 4 (text "if" <+> pprint guard <+> text "then"
<$> pprint block))
<$> printIf' xs e
printIf' [] Nothing = text "end"
printIf' [] (Just b) = group (nest 4 (text "else" </> pprint b)
<$> text "end")
printIf' ((guard, block):xs) e
= group (nest 4 (text "elseif" <+> pprint guard <+> text "then"
<$> pprint block))
<$> printIf' xs e
pprint (ForRange name e1 e2 e3 block)
= text "for" <+> text name <> equals <> pprint e1 <> comma <> pprint e2 <> e3' <+> text "do"
<$> indent 4 (pprint block)
<$> text "end"
where e3' = case e3 of
Nothing -> empty
Just e -> comma <> pprint e
pprint (ForIn names exps block)
= text "for" <+> (intercalate comma (map pprint names))
<+> text "in" <+> (intercalate comma (map pprint exps)) <+> text "do"
<$> indent 4 (pprint block)
<$> text "end"
pprint (FunAssign name body) = pprintFunction (Just (pprint name)) body
pprint (LocalFunAssign name body) = text "local" <+> pprintFunction (Just (pprint name)) body
pprint (LocalAssign names exps)
= text "local" <+> (intercalate comma (map pprint names)) <+> equals <+> exps'
where exps' = case exps of
Nothing -> empty
Just es -> intercalate comma (map pprint es)
pprint EmptyStat = empty