diff options
| author | Marvin Borner | 2022-07-16 23:36:46 +0200 |
|---|---|---|
| committer | Marvin Borner | 2022-07-16 23:36:46 +0200 |
| commit | 4c7d4174a2fcdea74d332cf7b407d6234c06bb2d (patch) | |
| tree | 60e068ff6bbd9f3c9b3b109ea3488fb386ef1b31 /src/Helper.hs | |
| parent | 88b0f7ed4e9580956f3be1eb50ce7cb10668207e (diff) | |
Got some things working
Diffstat (limited to 'src/Helper.hs')
| -rw-r--r-- | src/Helper.hs | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/src/Helper.hs b/src/Helper.hs index d45a02b..76a1f83 100644 --- a/src/Helper.hs +++ b/src/Helper.hs @@ -24,23 +24,25 @@ instance Show Expression where type Environment = [(String, Expression)] type Program = State Environment -decimalToBinary :: Integer -> Expression -decimalToBinary n = Abstraction $ Abstraction $ Abstraction $ Abstraction $ gen - n - where -- TODO: Consider switching 0 and 1 for better readability - fix 0 = 1 - fix 1 = 0 +likeTernary :: Expression -> Bool +likeTernary (Abstraction (Abstraction (Abstraction (Abstraction _)))) = True +likeTernary _ = False + +-- Dec to Bal3 in Bruijn encoding: reversed application with 0=>0; 1=>1; T=>2; end=>3 +-- e.g. 0=0=[[[[3]]]]; 2=1T=[[[[2 (0 3)]]]] -5=T11=[[[[0 (0 (2 3))]]]] +decimalToTernary :: Integer -> Expression +decimalToTernary n = + Abstraction $ Abstraction $ Abstraction $ Abstraction $ gen n + where gen 0 = Bruijn 3 - gen 1 = Application (Bruijn 0) (gen 0) - gen n | n < 0 = Application (Bruijn 2) (gen (-n)) - | otherwise = Application (Bruijn $ fix $ mod n 2) (gen $ div n 2) + gen n = Application (Bruijn $ fromIntegral $ mod n 3) (gen $ div (n + 1) 3) -binaryToDecimal :: Expression -> Integer -binaryToDecimal exp = sum $ zipWith (*) (resolve exp) (iterate (* 2) 1) +ternaryToDecimal :: Expression -> Integer +ternaryToDecimal exp = sum $ zipWith (*) (resolve exp) (iterate (* 3) 1) where - multiplier (Bruijn 0) = 1 - multiplier (Bruijn 1) = 0 - multiplier (Bruijn 2) = -1 -- TODO + multiplier (Bruijn 0) = 0 + multiplier (Bruijn 1) = 1 + multiplier (Bruijn 2) = (-1) resolve' (Application x@(Bruijn _) (Bruijn 3)) = [multiplier x] resolve' (Application fst@(Bruijn _) rst@(Application _ _)) = (multiplier fst) : (resolve' rst) |