{-# LANGUAGE TemplateHaskell #-}
-- | Types used in Normalize modules
module CLaSH.Normalize.Types where

import Control.Monad.State (State)
import Data.HashMap.Strict (HashMap)
import Data.Map            (Map)

import CLaSH.Core.Term     (Term, TmName)
import CLaSH.Core.Type     (Type)
import CLaSH.Rewrite.Types (Rewrite, RewriteSession)
import CLaSH.Util

-- | State of the 'NormalizeMonad'
data NormalizeState
  = NormalizeState
  { _normalized          :: HashMap TmName (Type,Term)
  -- ^ Global binders
  , _specialisationCache :: Map (TmName,Int,Either Term Type) (TmName,Type)
  -- ^ Cache of previously specialised functions:
  --
  -- * Key: (name of the original function, argument position, specialised term/type)
  --
  -- * Elem: (name of specialised function,type of specialised function)
  , _specialisationHistory :: HashMap TmName Int
  -- ^ Cache of how many times a function was specialized
  , _specialisationLimit :: Int
  -- ^ Number of time a function 'f' can be specialized
  , _inlineHistory   :: HashMap TmName (HashMap TmName Int)
  -- ^ Cache of function where inlining took place:
  --
  -- * Key: function where inlining took place
  --
  -- * Elem: (functions which were inlined, number of times inlined)
  , _inlineLimit     :: Int
  -- ^ Number of times a function 'f' can be inlined in a function 'g'
  , _curFun          :: TmName
  -- ^ Function which is currently normalized
  }

makeLenses ''NormalizeState

-- | State monad that stores specialisation and inlining information
type NormalizeMonad = State NormalizeState

-- | RewriteSession with extra Normalisation information
type NormalizeSession = RewriteSession NormalizeMonad

-- | A 'Transform' action in the context of the 'RewriteMonad' and 'NormalizeMonad'
type NormRewrite = Rewrite NormalizeMonad
