diff options
Diffstat (limited to 'src/Interpreter/Rep.hs')
| -rw-r--r-- | src/Interpreter/Rep.hs | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/src/Interpreter/Rep.hs b/src/Interpreter/Rep.hs index 1ded773..7add442 100644 --- a/src/Interpreter/Rep.hs +++ b/src/Interpreter/Rep.hs @@ -2,6 +2,8 @@ {-# LANGUAGE TypeFamilies #-} module Interpreter.Rep where +import Data.IORef +import qualified Data.Vector.Mutable as MV import GHC.TypeError import Array @@ -12,6 +14,22 @@ type family Rep t where Rep TNil = () Rep (TPair a b) = (Rep a, Rep b) Rep (TEither a b) = Either (Rep a) (Rep b) + Rep (TMaybe t) = Maybe (Rep t) Rep (TArr n t) = Array n (Rep t) Rep (TScal sty) = ScalRep sty - Rep (TAccum t) = TypeError (Text "Accumulator in Rep") + Rep (TAccum t) = IORef (RepAc t) + +type family RepAc t where + RepAc TNil = () + RepAc (TPair a b) = (RepAc a, RepAc b) + -- This is annoying when working with values of type 'RepAc t', because + -- failing a pattern match does not generate negative type information. + -- However, it works, saves us from having to defining a LEither type + -- first-class in the type system with + -- Rep (LEither a b) = Maybe (Either a b) + -- and it's not even incorrect, in a way. + RepAc (TMaybe (TEither a b)) = IORef (Maybe (Either (RepAc a) (RepAc b))) + RepAc (TMaybe t) = IORef (Maybe (RepAc t)) + RepAc (TArr n t) = (Shape n, MV.IOVector (RepAc t)) + RepAc (TScal sty) = IORef (ScalRep sty) + RepAc (TAccum t) = TypeError (Text "Nested accumulators") |