Language/Symantic/Lib/Monoid.hs

   1 {-# LANGUAGE UndecidableInstances #-}
   2 {-# OPTIONS_GHC -fno-warn-orphans #-}
   3 -- | Symantic for 'Monoid'.
   4 module Language.Symantic.Lib.Monoid where
   5
   6 import Control.Monad
   7 import qualified Data.Function as Fun
   8 import Data.Monoid (Monoid)
   9 import qualified Data.Monoid as Monoid
  10 import Data.Proxy
  11 import Data.Type.Equality ((:~:)(Refl))
  12 import Prelude hiding (Monoid(..))
  13
  14 import Language.Symantic.Parsing
  15 import Language.Symantic.Typing
  16 import Language.Symantic.Compiling
  17 import Language.Symantic.Interpreting
  18 import Language.Symantic.Transforming
  19 import Language.Symantic.Lib.Lambda
  20
  21 -- * Class 'Sym_Monoid'
  22 class Sym_Monoid term where
  23         mempty  :: Monoid a => term a
  24         mappend :: Monoid a => term a -> term a -> term a
  25         default mempty  :: (Trans t term, Monoid a) => t term a
  26         default mappend :: (Trans t term, Monoid a) => t term a -> t term a -> t term a
  27         mempty  = trans_lift mempty
  28         mappend = trans_map2 mappend
  29
  30 type instance Sym_of_Iface (Proxy Monoid) = Sym_Monoid
  31 type instance Consts_of_Iface (Proxy Monoid) = Proxy Monoid ': Consts_imported_by Monoid
  32 type instance Consts_imported_by Monoid = '[]
  33
  34 instance Sym_Monoid HostI where
  35         mempty  = HostI Monoid.mempty
  36         mappend = liftM2 Monoid.mappend
  37 instance Sym_Monoid TextI where
  38         mempty  = textI0 "mempty"
  39         mappend = textI2 "mappend"
  40 instance (Sym_Monoid r1, Sym_Monoid r2) => Sym_Monoid (DupI r1 r2) where
  41         mempty  = dupI0 (Proxy @Sym_Monoid) mempty
  42         mappend = dupI2 (Proxy @Sym_Monoid) mappend
  43
  44 -- | 'mappend' alias.
  45 --
  46 -- TODO: move to Semigroup
  47 (<>) ::
  48  ( Sym_Monoid term
  49  , Monoid a )
  50  => term a -> term a -> term a
  51 (<>) = mappend
  52 infixr 6 <>
  53
  54 instance
  55  ( Read_TypeNameR Type_Name cs rs
  56  , Inj_Const cs Monoid
  57  ) => Read_TypeNameR Type_Name cs (Proxy Monoid ': rs) where
  58         read_typenameR _cs (Type_Name "Monoid") k = k (ty @Monoid)
  59         read_typenameR _rs raw k = read_typenameR (Proxy @rs) raw k
  60 instance Show_Const cs => Show_Const (Proxy Monoid ': cs) where
  61         show_const ConstZ{} = "Monoid"
  62         show_const (ConstS c) = show_const c
  63
  64 instance Proj_ConC cs (Proxy Monoid)
  65 data instance TokenT meta (ts::[*]) (Proxy Monoid)
  66  = Token_Term_Monoid_mempty  (EToken meta '[Proxy Token_Type])
  67  | Token_Term_Monoid_mappend (EToken meta ts)
  68 deriving instance (Eq meta, Eq_Token meta ts) => Eq (TokenT meta ts (Proxy Monoid))
  69 deriving instance (Show meta, Show_Token meta ts) => Show (TokenT meta ts (Proxy Monoid))
  70 instance -- CompileI
  71  ( Read_TypeName Type_Name (Consts_of_Ifaces is)
  72  , Inj_Const  (Consts_of_Ifaces is) Monoid
  73  , Inj_Const  (Consts_of_Ifaces is) (->)
  74  , Proj_Con   (Consts_of_Ifaces is)
  75  , Compile is
  76  ) => CompileI is (Proxy Monoid) where
  77         compileI tok ctx k =
  78                 case tok of
  79                  Token_Term_Monoid_mempty tok_ty_a ->
  80                         -- mempty :: Monoid a => a
  81                         compile_type tok_ty_a $ \(ty_a::Type (Consts_of_Ifaces is) a) ->
  82                         check_kind
  83                          (At Nothing SKiType)
  84                          (At (Just tok_ty_a) $ kind_of ty_a) $ \Refl ->
  85                         check_con (At (Just tok_ty_a) (ty @Monoid :$ ty_a)) $ \Con ->
  86                         k ty_a $ TermO $ Fun.const mempty
  87                  Token_Term_Monoid_mappend tok_a ->
  88                         -- mappend :: Monoid a => a -> a -> a
  89                         compileO tok_a ctx $ \ty_a (TermO x) ->
  90                         check_con (At (Just tok_a) (ty @Monoid :$ ty_a)) $ \Con ->
  91                         k (ty_a ~> ty_a) $ TermO $
  92                          \c -> lam $ \y -> mappend (x c) y
  93 instance -- TokenizeT
  94  Inj_Token meta ts Monoid =>
  95  TokenizeT meta ts (Proxy Monoid) where
  96         tokenizeT _t = Monoid.mempty
  97          { tokenizers_infix = tokenizeTMod []
  98                  [ (Term_Name "mempty",) Term_ProTok
  99                          { term_protok = \meta -> ProTokPi $ \a ->
 100                                 ProTok $ inj_etoken meta $ Token_Term_Monoid_mempty a
 101                          , term_fixity = infixN5
 102                          }
 103                  , tokenize1 "mappend" infixN5 Token_Term_Monoid_mappend
 104                  , tokenize1 "<>" (infixR 6) Token_Term_Monoid_mappend
 105                  ]
 106          }
 107 instance Gram_Term_AtomsT meta ts (Proxy Monoid) g