{-# LANGUAGE NoImplicitPrelude #-}

-- | An efficient implementation of ordered maps from keys to values
-- (dictionaries).
--
-- API of this module is strict in both the keys and the values.
-- If you need value-lazy maps, use "Data.Map.Lazy" instead.
-- The 'Map' type is shared between the lazy and strict modules,
-- meaning that the same 'Map' value can be passed to functions in
-- both modules (although that is rarely needed).
--
-- These modules are intended to be imported qualified, to avoid name
-- clashes with Prelude functions, e.g.
--
-- >  import qualified Data.Map.Strict as Map
--
-- The implementation of 'Map' is based on /size balanced/ binary trees (or
-- trees of /bounded balance/) as described by:
--
--    * Stephen Adams, \"/Efficient sets: a balancing act/\",
--     Journal of Functional Programming 3(4):553-562, October 1993,
--     <http://www.swiss.ai.mit.edu/~adams/BB/>.
--    * J. Nievergelt and E.M. Reingold,
--      \"/Binary search trees of bounded balance/\",
--      SIAM journal of computing 2(1), March 1973.
--
--  Bounds for 'union', 'intersection', and 'difference' are as given
--  by
--
--    * Guy Blelloch, Daniel Ferizovic, and Yihan Sun,
--      \"/Just Join for Parallel Ordered Sets/\",
--      <https://arxiv.org/abs/1602.02120v3>.
--
-- Note that the implementation is /left-biased/ -- the elements of a
-- first argument are always preferred to the second, for example in
-- 'union' or 'insert'.
--
-- /Warning/: The size of the map must not exceed @maxBound::Int@. Violation of
-- this condition is not detected and if the size limit is exceeded, its
-- behaviour is undefined.
--
-- Operation comments contain the operation time complexity in
-- the Big-O notation (<http://en.wikipedia.org/wiki/Big_O_notation>).
--
-- Be aware that the 'Functor', 'Traversable' and 'Data' instances
-- are the same as for the "Data.Map.Lazy" module, so if they are used
-- on strict maps, the resulting maps will be lazy.

module Precursor.Data.Map
  ( Map
  , lookup
  , insert
  , delete
  ) where

import Data.Map.Strict