diff options
Diffstat (limited to 'lambda-calcul/haskell/src/Minilang/Lambda')
| -rw-r--r-- | lambda-calcul/haskell/src/Minilang/Lambda/DeBruijn.hs | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/lambda-calcul/haskell/src/Minilang/Lambda/DeBruijn.hs b/lambda-calcul/haskell/src/Minilang/Lambda/DeBruijn.hs index de179ad..025fd39 100644 --- a/lambda-calcul/haskell/src/Minilang/Lambda/DeBruijn.hs +++ b/lambda-calcul/haskell/src/Minilang/Lambda/DeBruijn.hs @@ -47,14 +47,16 @@ eval (App f a) = f' -> App f' a eval term = term -eval' :: Show ann => Env ann -> DeBruijn ann -> DeBruijn ann +eval' :: (Show ann, Eq ann) => Env ann -> DeBruijn ann -> DeBruijn ann eval' env (FV v) = case lookup v env of Just term -> term Nothing -> FV v eval' env (App f a) = case eval' env f of Lam _ body -> eval' env (substitute env 0 a body) - f' -> eval' env $ App f' a + f' -> if f' /= f + then eval' env $ App f' a + else App f' a eval' _ term = term substitute :: Env ann -> Int -> DeBruijn ann -> DeBruijn ann -> DeBruijn ann |