32 lines
1.1 KiB
Plaintext
32 lines
1.1 KiB
Plaintext
module Ast where
|
|
|
|
import Prelude
|
|
import Data.Tuple.Nested (type (/\), (/\))
|
|
|
|
|
|
newtype OutputNumber :: forall k. Type -> k -> Type
|
|
newtype OutputNumber number boolean = OutputNumber number
|
|
|
|
newtype OutputBoolean :: forall k. k -> Type -> Type
|
|
newtype OutputBoolean number boolean = OutputBoolean boolean
|
|
|
|
data Ast output
|
|
= Number (output Number Void)
|
|
| Boolean (output Void Number)
|
|
| Add (output (Ast output /\ Ast output) Void)
|
|
| And (output Void (Ast output /\ Ast output))
|
|
|
|
addition :: Ast OutputNumber
|
|
addition = Add $ OutputNumber ((Number $ OutputNumber 0.0) /\ (Number $ OutputNumber 1.1))
|
|
|
|
class ExtractFromOutput output where
|
|
extractLeft :: forall left. output left Void -> left
|
|
wrapLeft :: forall left right. left -> output left right
|
|
|
|
|
|
interpret :: forall output. Semiring (output Number Boolean) => ExtractFromOutput output => Ast output -> output Number Boolean
|
|
interpret (Add inner) = interpret left + interpret right
|
|
where
|
|
left /\ right = extractLeft inner
|
|
interpret (Number n) = wrapLeft $ extractLeft n
|
|
interpret a = interpret a |