-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Simple interface to the Concorde solver for the Traveling Salesperson Problem
--   
--   This package provides a simple interface to Concorde, a solver for the
--   Traveling Salesperson Problem (TSP). Concorde is available from
--   <a>http://www.tsp.gatech.edu/concorde/index.html</a>.
--   
--   This library uses the Lin–Kernighan heuristic via Concorde's
--   <tt>linkern</tt> program. It quickly produces good tours, which may
--   not be optimal. You can directly control the tradeoff between run time
--   and solution quality.
--   
--   An example program is included.
--   
--   Currently, only problems in two-dimensional Euclidean space are
--   supported.
--   
--   More features of Concorde can be added on request. Feature requests
--   and patches are always welcome.
@package concorde
@version 0.1


-- | Approximate a solution to 2D Euclidean TSP using the Lin-Kernighan
--   heuristic.
module Algorithms.Concorde.LinKern

-- | Approximate a solution to the two-dimensional Euclidean Traveling
--   Salesperson Problem, using the Lin-Kernighan heuristic.
--   
--   Invokes Concorde's <tt>linkern</tt> executable as an external process.
--   
--   Note: <tt>linkern</tt> uses Euclidean distance rounded to the nearest
--   integer. You may need to scale up coordinates in the function passed
--   to <tt><a>tsp</a></tt>.
tsp :: Config -> (a -> R2) -> [a] -> IO [a]

-- | A point in Euclidean two-dimensional space.
type R2 = (Double, Double)

-- | Configuration for <tt><a>tsp</a></tt>.
data Config
Config :: FilePath -> Bool -> Maybe Double -> Maybe Int -> Int -> [String] -> Config

-- | Path to the <tt>linkern</tt> executable. Searches <tt>$PATH</tt> by
--   default.
executable :: Config -> FilePath

-- | If set, write progress information to standard output.
verbose :: Config -> Bool

-- | Stop looking for better solutions after this many seconds.
timeBound :: Config -> Maybe Double

-- | Run this many optimization steps. Default is the number of points.
steps :: Config -> Maybe Int

-- | Run this many separate optimizations. Default is 1.
runs :: Config -> Int

-- | Other command-line arguments to the <tt>linkern</tt> executable.
otherArgs :: Config -> [String]

-- | Default configuration.
defConfig :: Config
instance Eq Config
instance Ord Config
instance Read Config
instance Show Config