Some cleanup and optparse

.gitignore

@@ -1 +1,2 @@
 *.cabal
+result*

Main.hs

@@ -3,20 +3,39 @@
 module Main where
 
 import Data.Attoparsec.Text (parseOnly)
+import Data.Either (fromRight)
+import Options.Applicative
 import qualified Data.Text.IO as T
 
 import INAST
 import INSolver
 
+data FCInsurersOpt = FCInsurersOpt
+  { path :: FilePath
+  , intInput :: Int
+  }
+
+fCInsurersOpt :: Parser FCInsurersOpt
+fCInsurersOpt = FCInsurersOpt
+  <$> strOption
+      ( long "network"
+     <> metavar "PATH"
+     <> help "the path to a file that defines a network" )
+  <*> option auto
+      ( long "input"
+     <> metavar "INT"
+     <> help "an integer input to the network" )
+
 main :: IO ()
-main = do
-  inputNetwork <- T.readFile "./input.network"
-  T.putStrLn "Using the following input network:"
-  T.putStrLn inputNetwork
-  T.putStrLn "Parsed AST:"
-  let Right insnet = parseOnly insuranceNetworkParser inputNetwork
-  print insnet
-  T.putStrLn "Problem solution, input=3:"
-  print $ solve (3::Int) insnet
-  T.putStrLn "Problem solution, input=6:"
-  print $ solve (6::Int) insnet
+main = fcinsurers =<< execParser opts
+  where
+    opts = info (fCInsurersOpt <**> helper)
+      ( fullDesc
+     <> progDesc "A small command line program that outputs a list of the \
+                  \ fewest contributing insurers (by their integer ids)"
+     <> header "Fewest Contributing Insurers (in23)" )
+
+fcinsurers :: FCInsurersOpt -> IO ()
+fcinsurers (FCInsurersOpt p i) = do
+  inputNetwork <- T.readFile p
+  print $ fromRight [] $ solve i <$> parseOnly insuranceNetworkParser inputNetwork

package.yaml

@@ -5,8 +5,9 @@ ghc-options: -Wall -threaded
 dependencies:
   - base == 4.*
   - attoparsec
-  - text
   - mtl
+  - optparse-applicative
+  - text
 
 executables:
   in23: