import Logic
-Succ=\n.\f.\x.(f ((n f) x))
-Zero=\f.\x.x
+Succ=\n f x.(f ((n f) x))
+Zero=\f x.x
One=(Succ Zero)
Two=(Succ One)
Three=(Succ Two)
-Add=\n.\m.\f.\x.((n f) ((m f) x))
-Mult=\n.\m.\f.(n (m f))
-IsZero=\n.\x.\y.((n \z.y) x)
+Add=\n m f x.((n f) ((m f) x))
+Mult=\n m f.(n (m f))
+IsZero=\n x y.((n \z.y) x)
((Add Two) Three)
((Mult Two) Three)
(PrintBool (IsZero Zero))
parseLambda :: Parser Term
parseLambda = do
char '\\'
- vars <- many1 (parseVar <* char ' ')
+ vars <- sepBy1 parseVar (char ' ')
char '.'
t <- parseTerm
return $! createLambda vars t
parseApp :: Parser Term
parseApp = do
+ aps <- sepBy1 (parseBraces <|> parseLambda <|> parseVar) (char ' ')
+ return $! createApp aps
+
+createApp :: [Term] -> Term
+createApp [t] = t
+createApp (t:ts:tss) = createApp (App t ts : tss)
+createApp [] = error "empty createApp"
+
+parseBraces :: Parser Term
+parseBraces = do
char '('
t <- parseTerm
- char ' '
- r <- parseTerm
char ')'
- return $! App t r
+ return t
parseTerm :: Parser Term
-parseTerm = parseVar <|> parseLambda <|> parseApp
+parseTerm = parseApp <|>
+ parseBraces <|>
+ parseLambda <|>
+ parseVar
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