documentation

diff --git a/fp.cabal b/fp.cabal
index 4c137d1..363a35c 100644 (file)
--- a/fp.cabal
+++ b/fp.cabal
@@ -17,8 +17,8 @@ cabal-version:       >=1.10
 
 library 
   exposed-modules: Lambda
 
 library 
   exposed-modules: Lambda

-  other-modules:   Lambda.Term

                    Lambda.Parser.Fancy
                    Lambda.Parser.Fancy

+  other-modules:   Lambda.Term

   build-depends:       base >=4.7 && <4.8
                      , text >=1.2 && <1.3
                      , attoparsec >=0.12 && <0.13
   build-depends:       base >=4.7 && <4.8
                      , text >=1.2 && <1.3
                      , attoparsec >=0.12 && <0.13

diff --git a/src/Lambda.hs b/src/Lambda.hs
index b3a25ce..3026b75 100644 (file)
--- a/src/Lambda.hs
+++ b/src/Lambda.hs
@@ -14,6 +14,7 @@ module Lambda
   ( -- * Types
     VarName
   , Term(..)
   ( -- * Types
     VarName
   , Term(..)

+  , pattern RedEx

     -- * Reduction
   , alphaNorm
   , reduce
     -- * Reduction
   , alphaNorm
   , reduce


@@ -75,9 +76,9 @@ reduce (App t u) = app (reduce t) u
 
 data Strategy = Eager | Lazy
 
 
 data Strategy = Eager | Lazy
 

-reduceStep :: (Monad m) => Term -> m Term
-reduceStep (RedEx x s t) = return $ substitute x t s
-reduceStep t = return t
+reduceStep :: Term -> Term
+reduceStep (RedEx x s t) = substitute x t s
+reduceStep t = t

 
 data Z = R Term Z | L Z Term | ZL VarName Z | E
 data D = Up | Down
 
 data Z = R Term Z | L Z Term | ZL VarName Z | E
 data D = Up | Down


@@ -96,6 +97,8 @@ unmove :: TermZipper -> TermZipper
 unmove (t, L c r, Down) = (App t r, c, Down)
 unmove x = x
 
 unmove (t, L c r, Down) = (App t r, c, Down)
 unmove x = x
 

+-- getTerm :: TermZipper -> Term
+

 travPost :: (Monad m) => (Term -> m Term) -> Term -> m Term
 travPost fnc term = tr fnc (term, E, Down)
   where 
 travPost :: (Monad m) => (Term -> m Term) -> Term -> m Term
 travPost fnc term = tr fnc (term, E, Down)
   where 


@@ -130,12 +133,13 @@ travPre fnc term = tr fnc (term, E, Down)
 -- >>> toNormalForm Lazy 100 $ (App (App cK cI) cY)
 -- Just (λx.x)
 --
 -- >>> toNormalForm Lazy 100 $ (App (App cK cI) cY)
 -- Just (λx.x)
 --

--- prop> (\ t u -> t == u || t == Nothing || u == Nothing) (alphaNorm <$> toNormalForm Lazy 1000 x) (alphaNorm <$> toNormalForm Eager 1000 x)
+-- prop> within 10000000 $ (\ t u -> t == u || t == Nothing || u == Nothing) (alphaNorm <$> toNormalForm Lazy 1000 x) (alphaNorm <$> toNormalForm Eager 1000 x)

 
 

+-- inf = tRead "(\\d.a ((\\d c.c d c) (\\x y z.x z (y z)) (\\f.(\\x.f (x x)) (\\x.f (x x))) e))"

 
 toNormalForm :: Strategy -> Int -> Term -> Maybe Term
 
 toNormalForm :: Strategy -> Int -> Term -> Maybe Term

-toNormalForm Eager n = flip evalStateT 0 . travPost (cnt >=> short n >=> reduceStep)
-toNormalForm Lazy  n = flip evalStateT 0 . travPre  (cnt >=> short n >=> reduceStep)
+toNormalForm Eager n = flip evalStateT 0 . travPost (cnt >=> short n >=> return . reduceStep)
+toNormalForm Lazy  n = flip evalStateT 0 . travPre  (cnt >=> short n >=> return . reduceStep)

 
 cnt :: (Monad m) => Term -> StateT Int m Term
 cnt t@RedEx{} = do
 
 cnt :: (Monad m) => Term -> StateT Int m Term
 cnt t@RedEx{} = do

diff --git a/src/Lambda/Parser/Fancy.hs b/src/Lambda/Parser/Fancy.hs
index 48593dd..b0f0c2d 100644 (file)
--- a/src/Lambda/Parser/Fancy.hs
+++ b/src/Lambda/Parser/Fancy.hs
@@ -16,7 +16,10 @@
 
 -- TODO: proper documentation
 
 
 -- TODO: proper documentation
 

-module Lambda.Parser.Fancy where
+module Lambda.Parser.Fancy 
+  ( tRead
+  , parseTerm
+  )  where

 
 import Data.Text as T hiding (map)
 import Data.Attoparsec.Text
 
 import Data.Text as T hiding (map)
 import Data.Attoparsec.Text

diff --git a/src/Lambda/Term.hs b/src/Lambda/Term.hs
index e3682c1..a783a66 100644 (file)
--- a/src/Lambda/Term.hs
+++ b/src/Lambda/Term.hs
@@ -11,7 +11,15 @@
 -- Data types for λ terms.
 
 
 -- Data types for λ terms.
 
 

-module Lambda.Term where
+module Lambda.Term
+  ( -- * Types
+    VarName
+  , Term(..)
+    -- * Pattern synonyms
+  , pattern RedEx
+  , pattern AppApp
+  , pattern EmLambda
+  ) where

 
 type VarName = String
 
 
 type VarName = String
 


@@ -20,5 +28,3 @@ data Term = Var VarName | Lambda VarName Term | App Term Term deriving (Eq)
 pattern RedEx x t s = App (Lambda x t) s
 pattern AppApp a b c = App a (App b c)
 pattern EmLambda x y t = Lambda x (Lambda y t)
 pattern RedEx x t s = App (Lambda x t) s
 pattern AppApp a b c = App a (App b c)
 pattern EmLambda x y t = Lambda x (Lambda y t)

-
-