-- {-# LANGUAGE NoImplicitPrelude #-} -- import qualified Prelude as P module Data.Internal ( Map(..), Variable(..), Bound(..), Bounds(..), Constraints(..), Optimization(..), Type(..), MIPSolution(..), LPSolution(..), ) where import Data.List (intercalate) import qualified Data.Vector as V import qualified Data.HashMap.Strict as M import Data.Hashable import Data.Monoid import qualified Data.HashSet as S type Map k v = M.HashMap k v data Variable a = Double :# a data Bound x = x :< Double | x :> Double | x := Double deriving Show newtype Constraints a = Constraints [ Bound [Variable a] ] simplifyVars :: (Eq a, Hashable a) => [Variable a] -> [Variable a] simplifyVars vars = map (\(v,c) -> c :# v) \$ M.toList \$ foldr (\(c :# v) m -> M.insertWith (+) v c m) M.empty vars simplifyBounds (xs :< b) = (simplifyVars xs) :< b simplifyBounds (xs := b) = (simplifyVars xs) := b simplifyBounds (xs :> b) = (simplifyVars xs) :> b simplifyConstraints :: (Eq a, Hashable a) => Constraints a -> Constraints a simplifyConstraints (Constraints cs) = Constraints \$ map simplifyBounds cs removeEmptyConstraints :: (Eq a, Hashable a) => Constraints a -> Constraints a removeEmptyConstraints (Constraints cs) = Constraints \$ filter isNonEmpty cs where isNonEmpty ([] :< b) = False isNonEmpty ([] := b) = False isNonEmpty ([] :> b) = False isNonEmpty _ = True data Optimization a = Maximize [Variable a] | Minimize [Variable a] data Type = TContinuous | TInteger | TBinary instance (Show a) => Show (Variable a) where show (d :# v) | d == (-1) = "-" ++ (show v) | d == 1 = (show v) | otherwise = (show d) ++ "x" ++ (show v) instance Show a => Show (Optimization a) where show (Minimize xs) = "Minimize\n\t" ++ (intercalate "+" \$ map show xs) show (Maximize xs) = "Maximize\n\t" ++ (intercalate "+" \$ map show xs) showVars xs = intercalate " + " \$ map show \$ zipWith (:#) xs [0..] instance (Show a) => Show (Constraints a) where show (Constraints bounds) = "\nSubject to\n" ++ (unlines \$ map (\a -> "\t" ++ a) \$ map getVarSigns bounds) printVars xs = intercalate " + " \$ map show xs getVarSigns (x :< v) = (printVars x) ++ " <= " ++ (show v) getVarSigns (x :> v) = (printVars x) ++ " >= " ++ (show v) getVarSigns (x := v) = (printVars x) ++ " == " ++ (show v) instance Show Type where show TContinuous = "Continous" show TInteger = "Integer" show TBinary = "Binary" type Bounds = [Bound Int] data MIPSolution a = MIPSolution { mipOptimalSol :: Bool, mipObjVal :: Double, mipVars :: Map a Double } deriving (Show) data LPSolution a = LPSolution { lpOptimalSol :: Bool, lpObjVal :: Double, lpVars :: Map a Double, lpDualVars :: V.Vector Double, lpBasisVars :: Maybe (S.HashSet a)} deriving (Show)