diff options
Diffstat (limited to 'Math/LinProg/LP.hs')
| -rw-r--r-- | Math/LinProg/LP.hs | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/Math/LinProg/LP.hs b/Math/LinProg/LP.hs index 5f9e168..1fc59e0 100644 --- a/Math/LinProg/LP.hs +++ b/Math/LinProg/LP.hs @@ -1,5 +1,18 @@ {-# LANGUAGE TemplateHaskell, FlexibleInstances, ScopedTypeVariables #-} +{-| +Module : Math.LinProg.LP +Description : Compiles LP monad and expressions to a intermediate form. +Copyright : (c) Justin Bedő, 2014 +License : BSD +Maintainer : cu@cua0.org +Stability : experimental +Linear programs that are specified using the monadic construction are compiled +to an intermediate data structure that's easier to work with. The compiled +state groups objective terms and splits (in)equality constraints into LHS and +RHS terms, with the LHS containing all variables and the RHS terms containing +fixed constants. +-} module Math.LinProg.LP ( compile ,Equation @@ -17,6 +30,7 @@ import Control.Monad.Free type Equation t v = (LinExpr t v, t) -- LHS and RHS +-- | Compiled state contatining the objective and (in)equality statements. data CompilerS t v = CompilerS { _objective :: LinExpr t v ,_equals :: [Equation t v] @@ -25,6 +39,7 @@ data CompilerS t v = CompilerS { $(makeLenses ''CompilerS) +-- | Compiles a linear programming monad to intermediate form which is easier to process compile :: (Num t, Show t, Ord t, Eq v) => LinProg t v () -> CompilerS t v compile ast = compile' ast initCompilerS where compile' (Free (Objective a c)) state = compile' c $ state & objective +~ a @@ -37,7 +52,7 @@ compile ast = compile' ast initCompilerS where [] [] --- Printing to LP format +-- | Shows a compiled state as LP format. Requires variable ids are strings. instance (Show t, Num t, Ord t) => Show (CompilerS t String) where show s = unlines $ catMaybes [ Just "Minimize" |