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sourcecode:
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module FlatCurry.Show
( showFlatProg, showFlatType, showFlatFunc
, showCurryType, isClassContext
, showCurryExpr, showCurryId, showCurryVar
)
where
import FlatCurry.Types
import Data.List
import Data.Char
--- Shows a FlatCurry program term as a string (with some pretty printing).
showFlatProg :: Prog -> String
showFlatProg (Prog modname imports types funcs ops) =
" (Prog " ++ show modname
++ (if null imports then "\n []" else
"\n [" ++ showFlatListElems show imports ++ "]")
++ (if null types then "\n []" else
"\n [" ++ showFlatListElems showFlatType types ++ "\n ]")
++ "\n [" ++ showFlatListElems showFlatFunc funcs ++ "\n ]"
++ "\n " ++ showFlatList showFlatOp ops
++ "\n )\n"
showFlatVisibility :: Visibility -> String
showFlatVisibility Public = " Public "
showFlatVisibility Private = " Private "
showFlatFixity :: Fixity -> String
showFlatFixity InfixOp = " InfixOp "
showFlatFixity InfixlOp = " InfixlOp "
showFlatFixity InfixrOp = " InfixrOp "
showFlatOp :: OpDecl -> String
showFlatOp (Op name fix prec) =
"(Op " ++ show name ++ showFlatFixity fix ++ show prec ++ ")"
showFlatType :: TypeDecl -> String
showFlatType (Type name vis tpars consdecls) =
"\n (Type " ++ show name ++ showFlatVisibility vis
++ showFlatList show tpars
++ showFlatList showFlatCons consdecls ++ ")"
showFlatType (TypeSyn name vis tpars texp) =
"\n (TypeSyn " ++ show name ++ showFlatVisibility vis
++ showFlatList show tpars
++ showFlatTypeExpr texp ++ ")"
showFlatType (TypeNew name vis tpars consdecl) =
"\n (TypeNew " ++ show name ++ showFlatVisibility vis
++ showFlatList show tpars
++ showFlatNewCons consdecl ++ ")"
showFlatCons :: ConsDecl -> String
showFlatCons (Cons cname arity vis types) =
"(Cons " ++ show cname ++ " " ++ show arity
++ showFlatVisibility vis
++ showFlatList showFlatTypeExpr types ++ ")"
showFlatNewCons :: NewConsDecl -> String
showFlatNewCons (NewCons cname vis texp) =
"(NewCons " ++ show cname
++ showFlatVisibility vis
++ showFlatTypeExpr texp ++ ")"
showFlatFunc :: FuncDecl -> String
showFlatFunc (Func name arity vis ftype rl) =
"\n (Func " ++ show name ++ " " ++ show arity ++ " "
++ showFlatVisibility vis ++
"\n " ++ showFlatTypeExpr ftype ++
"\n " ++ showFlatRule rl ++ ")"
showFlatRule :: Rule -> String
showFlatRule (Rule params expr) =
" (Rule " ++ showFlatList show params
++ showFlatExpr expr ++ ")"
showFlatRule (External name) =
" (External " ++ show name ++ ")"
showFlatTypeExpr :: TypeExpr -> String
showFlatTypeExpr (FuncType t1 t2) =
"(FuncType " ++ showFlatTypeExpr t1 ++ " " ++ showFlatTypeExpr t2 ++ ")"
showFlatTypeExpr (TCons tc ts) =
"(TCons " ++ show tc
++ showFlatList showFlatTypeExpr ts ++ ")"
showFlatTypeExpr (TVar n) = "(TVar " ++ show n ++ ")"
showFlatTypeExpr (ForallType tvs te) =
"(ForallType " ++ showFlatList show tvs ++ showFlatTypeExpr te ++ ")"
showFlatCombType :: CombType -> String
showFlatCombType FuncCall = "FuncCall"
showFlatCombType ConsCall = "ConsCall"
showFlatCombType (FuncPartCall n) = "(FuncPartCall " ++ show n ++ ")"
showFlatCombType (ConsPartCall n) = "(ConsPartCall " ++ show n ++ ")"
showFlatExpr :: Expr -> String
showFlatExpr (Var n) = "(Var " ++ show n ++ ")"
showFlatExpr (Lit l) = "(Lit " ++ showFlatLit l ++ ")"
showFlatExpr (Comb ctype cf es) =
"(Comb " ++ showFlatCombType ctype ++ " "
++ show cf ++ showFlatList showFlatExpr es ++ ")"
showFlatExpr (Let bindings exp) =
"(Let " ++ showFlatList showFlatBinding bindings ++ showFlatExpr exp ++ ")"
where showFlatBinding (x,e) = "("++show x++","++showFlatExpr e++")"
showFlatExpr (Free xs e) =
"(Free " ++ showFlatList show xs ++ showFlatExpr e ++ ")"
showFlatExpr (Or e1 e2) =
"(Or " ++ showFlatExpr e1 ++ " " ++ showFlatExpr e2 ++ ")"
showFlatExpr (Case Rigid e bs) =
"(Case Rigid " ++ showFlatExpr e ++ showFlatList showFlatBranch bs ++ ")"
showFlatExpr (Case Flex e bs) =
"(Case Flex " ++ showFlatExpr e ++ showFlatList showFlatBranch bs ++ ")"
showFlatExpr (Typed e ty) =
"(Typed " ++ showFlatExpr e ++ ' ' : showFlatTypeExpr ty ++ ")"
showFlatLit :: Literal -> String
showFlatLit (Intc i) = "(Intc " ++ show i ++ ")"
showFlatLit (Floatc f) = "(Floatc " ++ show f ++ ")"
showFlatLit (Charc c) = "(Charc " ++ show c ++ ")"
showFlatBranch :: BranchExpr -> String
showFlatBranch (Branch p e) = "(Branch " ++ showFlatPattern p
++ showFlatExpr e ++ ")"
showFlatPattern :: Pattern -> String
showFlatPattern (Pattern qn xs) =
"(Pattern " ++ show qn
++ showFlatList show xs ++ ")"
showFlatPattern (LPattern lit) = "(LPattern " ++ showFlatLit lit ++ ")"
-- format a finite list of elements:
showFlatList :: (a->String) -> [a] -> String
showFlatList format elems = " [" ++ showFlatListElems format elems ++ "] "
showFlatListElems :: (a->String) -> [a] -> String
showFlatListElems format elems = intercalate "," (map format elems)
------------------------------------------------------------------------------
--- Shows a FlatCurry type in Curry syntax.
---
--- @param trans - a translation function from qualified type names
--- to external type names
--- @param nested - True iff brackets must be written around complex types
--- @param texpr - the FlatCurry type expression to be formatted
--- @return the String representation of the formatted type expression
showCurryType :: (QName -> String) -> Bool -> TypeExpr -> String
showCurryType tf nested = showTypeWithClass []
where
showTypeWithClass cls texp = case texp of
ForallType _ te -> showTypeWithClass cls te -- strip forall quantifiers
FuncType t1 t2 -> maybe (showClassedType cls texp)
(\ (cn,cvs) ->
showTypeWithClass (cls ++ [(cn,cvs)]) t2)
(isClassContext t1)
_ -> showClassedType cls texp
showClassedType cls texp
| null cls
= showCurryType_ tf nested texp
| otherwise
= showBracketsIf nested $
showBracketsIf (length cls > 1)
(intercalate ", "
(map (\ (cn,cvs) -> unwords $
cn : map (\cv -> showCurryType_ tf True cv) cvs)
cls)) ++
" => " ++ showCurryType_ tf False texp
--- Tests whether a FlatCurry type is a class context.
--- If it is the case, return the class name and the type parameters
--- of the class context.
isClassContext :: TypeExpr -> Maybe (String,[TypeExpr])
isClassContext texp = case texp of
TCons (_,tc) ts -> checkDictCons tc ts
-- a class context might be represented as function `() -> Dict`:
FuncType (TCons unit []) (TCons (_,tc) ts) | unit == ("Prelude","()")
-> checkDictCons tc ts
_ -> Nothing
where
checkDictCons tc ts | take 6 tc == "_Dict#" = Just (drop 6 tc, ts)
| otherwise = Nothing
------------------------------
showCurryType_ :: (QName -> String) -> Bool -> TypeExpr -> String
showCurryType_ _ _ (TVar i) = if i<5 then [chr (97+i)] else 't':show i
showCurryType_ tf nested (FuncType t1 t2) =
showBracketsIf nested
(showCurryType_ tf (isFuncType t1) t1 ++ " -> " ++
showCurryType_ tf False t2)
showCurryType_ tf nested (TCons tc ts)
| null ts = tf tc
| tc==("Prelude","[]") && (head ts == TCons ("Prelude","Char") [])
= "String"
| tc==("Prelude","[]")
= "[" ++ showCurryType_ tf False (head ts) ++ "]" -- list type
| take 2 (snd tc) == "(," -- tuple type
= "(" ++ intercalate "," (map (showCurryType_ tf False) ts) ++ ")"
| otherwise
= showBracketsIf nested
(tf tc ++ concatMap (\t->' ':showCurryType_ tf True t) ts)
showCurryType_ tf nested (ForallType tvs te) =
showBracketsIf nested
(unwords ("forall" : map (showCurryType_ tf False . TVar . fst) tvs) ++ " . " ++
showCurryType_ tf False te)
isFuncType :: TypeExpr -> Bool
isFuncType (TVar _) = False
isFuncType (FuncType _ _) = True
isFuncType (TCons _ _) = False
isFuncType (ForallType _ te) = isFuncType te
------------------------------------------------------------------------------
--- Shows a FlatCurry expressions in (almost) Curry syntax.
---
--- @param trans - a translation function from qualified functions names
--- to external function names
--- @param nested - True iff brackets must be written around complex terms
--- @param indent - the indentation used in case expressions and if-then-else
--- @param expr - the FlatCurry expression to be formatted
--- @return the String representation of the formatted expression
showCurryExpr :: (QName -> String) -> Bool -> Int -> Expr -> String
showCurryExpr _ _ _ (Var n) = showCurryVar n
showCurryExpr _ _ _ (Lit l) = showCurryLit l
showCurryExpr tf _ _ (Comb _ cf []) = showCurryId (tf cf)
showCurryExpr tf nested b (Comb _ cf [e]) =
showBracketsIf nested (showCurryId (tf cf) ++ " "
++ showCurryExpr tf True b e)
showCurryExpr tf nested b (Comb ct cf [e1,e2])
| cf==("Prelude","apply")
= showBracketsIf nested
(showCurryExpr tf True b e1 ++ " " ++ showCurryExpr tf True b e2)
| isAlpha (head (snd cf))
= showBracketsIf nested
(tf cf ++" "++ showCurryElems (showCurryExpr tf True b) [e1,e2])
| isFiniteList (Comb ct cf [e1,e2])
= if isStringConstant (Comb ct cf [e1,e2])
then "\"" ++ showCurryStringConstant (Comb ct cf [e1,e2]) ++ "\""
else "[" ++
intercalate "," (showCurryFiniteList tf b (Comb ct cf [e1,e2]))
++ "]"
| snd cf == "(,)" -- pair constructor?
= "(" ++ showCurryExpr tf False b e1 ++ "," ++
showCurryExpr tf False b e2 ++ ")"
| otherwise
= showBracketsIf nested
(showCurryExpr tf True b e1 ++ " " ++ tf cf ++ " " ++
showCurryExpr tf True b e2 )
showCurryExpr tf nested b (Comb _ cf (e1:e2:e3:es))
| cf==("Prelude","if_then_else") && null es
= showBracketsIf nested
("\n" ++
sceBlanks b ++ " if " ++ showCurryExpr tf False (b+2) e1 ++ "\n" ++
sceBlanks b ++ " then " ++ showCurryExpr tf False (b+2) e2 ++ "\n" ++
sceBlanks b ++ " else " ++ showCurryExpr tf False (b+2) e3)
| take 2 (snd cf) == "(," -- tuple constructor?
= "(" ++
intercalate "," (map (showCurryExpr tf False b) (e1:e2:e3:es))
++ ")"
| otherwise
= showBracketsIf nested
(showCurryId (tf cf) ++ " "
++ showCurryElems (showCurryExpr tf True b) (e1:e2:e3:es))
showCurryExpr tf nested b (Let bindings exp) =
showBracketsIf nested
("\n" ++ sceBlanks b ++ "let " ++
intercalate ("\n " ++ sceBlanks b)
(map (\ (x,e) -> showCurryVar x ++ " = " ++
showCurryExpr tf False (b+4) e) bindings) ++
("\n" ++ sceBlanks b ++ " in ") ++ showCurryExpr tf False (b+4) exp)
showCurryExpr tf nested b (Free [] e) = showCurryExpr tf nested b e
showCurryExpr tf nested b (Free (x:xs) e) =
showBracketsIf nested
("let " ++ intercalate "," (map showCurryVar (x:xs)) ++
" free in " ++ showCurryExpr tf False b e)
showCurryExpr tf nested b (Or e1 e2) =
showBracketsIf nested
(showCurryExpr tf True b e1 ++ " ? " ++ showCurryExpr tf True b e2)
showCurryExpr tf nested b (Case ctype e cs) =
showBracketsIf nested
((case ctype of Rigid -> "case "
Flex -> "fcase ") ++
showCurryExpr tf True b e ++ " of\n " ++
showCurryElems (showCurryCase tf (b+2)) cs ++ sceBlanks b)
showCurryExpr tf nested b (Typed e ty) =
showBracketsIf nested
(showCurryExpr tf True b e ++ " :: " ++ showCurryType tf False ty)
showCurryVar :: Show a => a -> String
showCurryVar i = "v" ++ show i
--- Shows an identifier in Curry form. Thus, operators are enclosed in brackets.
showCurryId :: String -> String
showCurryId name | isAlpha (head name) = name
| name == "[]" = name
| otherwise = ('(':name)++")"
showCurryLit :: Literal -> String
showCurryLit (Intc i) = show i
showCurryLit (Floatc f) = show f
showCurryLit (Charc c) = show c
showCurryCase :: (QName -> String) -> Int -> BranchExpr -> String
showCurryCase tf b (Branch (Pattern l vs) e) =
sceBlanks b ++ showPattern (tf l) vs
++ " -> " ++ showCurryExpr tf False b e ++ "\n"
where
showPattern c [] = c
showPattern c [x] = c ++ " " ++ showCurryVar x
showPattern c [x1,x2] =
if isAlpha (head c)
then c ++ " " ++ showCurryVar x1 ++ " " ++ showCurryVar x2
else if c=="(,)" -- pair constructor?
then "(" ++ showCurryVar x1 ++ "," ++ showCurryVar x2 ++ ")"
else showCurryVar x1 ++ " " ++ c ++ " " ++ showCurryVar x2
showPattern c (x1:x2:x3:xs) =
if take 2 c == "(," -- tuple constructor?
then "(" ++ intercalate "," (map showCurryVar (x1:x2:x3:xs)) ++ ")"
else c ++ " " ++ showCurryElems showCurryVar (x1:x2:x3:xs)
showCurryCase tf b (Branch (LPattern l) e) =
sceBlanks b ++ showCurryLit l ++ " "
++ " -> " ++ showCurryExpr tf False b e ++ "\n"
showCurryFiniteList :: (QName -> String) -> Int -> Expr -> [String]
showCurryFiniteList tf b exp = case exp of
Comb _ ("Prelude","[]") [] -> []
Comb _ ("Prelude",":") [e1,e2] ->
showCurryExpr tf False b e1 : showCurryFiniteList tf b e2
_ -> error "Internal error in FlatCurry.Show.showCurryFiniteList"
-- show a string constant
showCurryStringConstant :: Expr -> String
showCurryStringConstant exp = case exp of
Comb _ ("Prelude","[]") [] -> []
Comb _ ("Prelude",":") [Lit (Charc c), e2] ->
showChar c ++ showCurryStringConstant e2
_ -> error "Internal error in FlatCurry.Show.showCurryStringConstant"
where
showChar c
| c=='"' = "\\\""
| c=='\'' = "\\\'"
| c=='\n' = "\\n"
| o < 32 || o > 126
= ['\\', chr (o `div` 100 + 48), chr (((o `mod` 100) `div` 10 + 48)),
chr(o `mod` 10 + 48)]
| otherwise = [c]
where
o = ord c
showCurryElems :: (a -> String) -> [a] -> String
showCurryElems format elems = intercalate " " (map format elems)
showBracketsIf :: Bool -> String -> String
showBracketsIf nested s = if nested then '(' : s ++ ")" else s
sceBlanks :: Int -> String
sceBlanks b = take b (repeat ' ')
-- Is the expression a finite list (with an empty list at the end)?
isFiniteList :: Expr -> Bool
isFiniteList (Var _) = False
isFiniteList (Lit _) = False
isFiniteList (Comb _ name args)
| name==("Prelude","[]") && null args = True
| name==("Prelude",":") && length args == 2 = isFiniteList (args!!1)
| otherwise = False
isFiniteList (Let _ _) = False
isFiniteList (Free _ _) = False
isFiniteList (Or _ _) = False
isFiniteList (Case _ _ _) = False
isFiniteList (Typed e _) = isFiniteList e
-- Is the expression a string constant?
isStringConstant :: Expr -> Bool
isStringConstant e = case e of
Comb _ name args -> (name==("Prelude","[]") && null args) ||
(name==("Prelude",":") && length args == 2 &&
isCharConstant (head args) && isStringConstant (args!!1))
_ -> False
-- Is the expression a character constant?
isCharConstant :: Expr -> Bool
isCharConstant e = case e of
Lit (Charc _) -> True
_ -> False
------------------------------------------------------------------------------
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