add 'makeEffect' template stub

agora/Agora/Effect.hs

@@ -5,4 +5,33 @@ Description: Helpers for constructing effects
 
 Helpers for constructing effects.
 -}
-module Agora.Effect () where
+module Agora.Effect (makeEffect) where
+
+import Plutarch.Api.V1 (PScriptPurpose (PSpending), PTxInfo, PTxOutRef, PValidator)
+import Plutarch.Internal (punsafeCoerce)
+import Plutarch.Monadic qualified as P
+
+--------------------------------------------------------------------------------
+
+-- | Helper 'template' for creating effect validator.
+makeEffect ::
+  forall (datum :: PType) (s :: S).
+  PIsData datum =>
+  (Term s datum -> Term s PTxOutRef -> Term s PTxInfo -> Term s POpaque) ->
+  Term s PValidator
+makeEffect f =
+  plam $ \datum _redeemer ctx' -> P.do
+    ctx <- pletFields @'["txInfo", "purpose"] ctx'
+    txInfo' <- plet ctx.txInfo
+
+    let datum' :: Term _ datum
+        datum' = pfromData $ punsafeCoerce datum
+
+    PSpending txOutRef <- pmatch $ pfromData ctx.purpose
+    txOutRef' <- plet (pfield @"_0" # txOutRef)
+
+    -- TODO: Here, check that a *single* GAT is burned.
+
+    f datum' txOutRef' txInfo'
+
+--------------------------------------------------------------------------------

agora/Agora/Governor.hs

@@ -5,7 +5,7 @@ Description: Governor entity scripts acting as authority of entire system.
 
 Governor entity scripts acting as authority of entire system.
 -}
-module Agora.Governor (GovernorDatum (..)) where
+module Agora.Governor (GovernorDatum (..), GovernorRedeemer (..)) where
 
 import Agora.Proposal (ProposalThresholds)
 

agora/PPrelude.hs

@@ -11,7 +11,8 @@ module PPrelude (
   module Plutarch,
 ) where
 
--- These are not exported by Plutarch.Prelude, for some reason. Maybe we can 'fix' this upstream?
-import Plutarch (ClosedTerm, compile)
+-- NOTE: These are not exported by Plutarch.Prelude, for some reason.
+-- Maybe we can 'fix' this upstream?
+import Plutarch (ClosedTerm, POpaque, compile)
 import Plutarch.Prelude
 import Prelude