add cost estimates

1 files changed, 31 insertions, 3 deletions

diff --git a/Cost.hs b/Cost.hs
index 31f00a3..5aa349c 100644
--- a/Cost.hs
+++ b/Cost.hs
@@ -56,8 +56,8 @@ spotAWS = DataCenterPrice
 -- which is unlikely to be the case; typically there will be many more
 -- cores than GPUs. So, this underestimates the price to brute force
 -- operations which run faster on GPUs.
-estimateAttack :: DataCenterPrice -> Cost BruteForceOp -> Dollars
-estimateAttack dc opcost = centsToDollars $ costcents
+estimateAttackCost :: DataCenterPrice -> Cost BruteForceOp -> Dollars
+estimateAttackCost dc opcost = centsToDollars $ costcents
   where
 	(Seconds cpuseconds) = fst (totalCost opcost)
 	cpuyears = cpuseconds `div` (60*60*24*365)
@@ -70,7 +70,35 @@ newtype Cents = Cents Integer
 	deriving (Num, Integral, Enum, Real, Ord, Eq, Show)
 
 newtype Dollars = Dollars Integer
-	deriving (Num, Integral, Enum, Real, Ord, Eq, Show)
+	deriving (Num, Integral, Enum, Real, Ord, Eq)
+
+instance Show Dollars where
+	show (Dollars n) = go 
+		[ (1000000000000, "trillion")
+		, (1000000000, "billion")
+		, (1000000, "million")
+		, (1000, "thousand")
+		]
+	  where
+		go [] = "$" ++ show n
+		go ((d, u):us)
+			| n >= d = 
+				let n' = n `div` d
+				in "$" ++ show n' ++ " " ++ u
+			| otherwise = go us
 
 centsToDollars :: Cents -> Dollars
 centsToDollars (Cents c) = Dollars (c `div` 100)
+
+type Year = Integer
+
+-- | Apply Moore's law to show how a cost might vary over time.
+costOverTime :: Dollars -> Year -> [(Dollars, Year)]
+costOverTime (Dollars currcost) thisyear = 
+	(Dollars currcost, thisyear) : map calc otheryears
+  where
+	otheryears = [thisyear+1, thisyear+5, thisyear+10]
+	calc y = 
+		let monthdelta = (fromIntegral ((y * 12) - (thisyear * 12))) :: Double
+		    cost = floor $ fromIntegral currcost / 2 ** (monthdelta / 18)
+		in (Dollars cost, y)