diff options
Diffstat (limited to 'src/Reducer.hs')
| -rw-r--r-- | src/Reducer.hs | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/src/Reducer.hs b/src/Reducer.hs index 87d8859..ddf2439 100644 --- a/src/Reducer.hs +++ b/src/Reducer.hs @@ -34,14 +34,10 @@ step (Application e1 e2) = Application (step e1) (step e2) step (Abstraction e) = Abstraction (step e) step _ = error "invalid" -reduceable :: Expression -> Bool -reduceable (Bruijn _) = False -reduceable (Variable _) = True -reduceable (Application (Abstraction _) _) = True -reduceable (Application e1 e2) = reduceable e1 || reduceable e2 -reduceable (Abstraction e) = reduceable e -reduceable _ = error "invalid" +-- until eq +converge :: Eq a => (a -> a) -> a -> a +converge = until =<< ((==) =<<) -- alpha conversion is not needed with de bruijn indexing reduce :: Expression -> Expression -reduce = until (not . reduceable) step +reduce = converge step |