From: Tomas Musil <tomik.musil@gmail.com>
Date: Wed, 3 Dec 2014 15:15:42 +0000 (+0100)
Subject: multiple applications
X-Git-Url: http://git.tomasm.cz/fp.git/commitdiff_plain/494e6afee1f1c583a880fca4e1f234de6823271a?ds=inline;hp=e9fefc72cffd266f05269f87992606365f8bd57a

multiple applications
---

diff --git a/Arithmetic.lc b/Arithmetic.lc
index 5a30a17..6851970 100644
--- a/Arithmetic.lc
+++ b/Arithmetic.lc
@@ -1,12 +1,12 @@
 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))
diff --git a/Logic.lc b/Logic.lc
index 27b52fc..8193a34 100644
--- a/Logic.lc
+++ b/Logic.lc
@@ -1,5 +1,5 @@
-True=\x.\y.x
-False=\x.\y.y
-And=\a.\b.((a b) False)
+True=\x y.x
+False=\x y.y
+And=\a b.((a b) False)
 If=\x.x
 PrintBool=\x.(((If x) TRUE) FALSE)
diff --git a/src/Lambda.hs b/src/Lambda.hs
index f9fbe2b..54c4065 100644
--- a/src/Lambda.hs
+++ b/src/Lambda.hs
@@ -28,7 +28,7 @@ parseVar = do
 parseLambda :: Parser Term
 parseLambda = do
   char '\\'
-  vars <- many1 (parseVar <* char ' ')
+  vars <- sepBy1 parseVar (char ' ')
   char '.'
   t <- parseTerm
   return $! createLambda vars t
@@ -40,15 +40,26 @@ createLambda _ _ = error "createLambda failed"
 
 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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