Merge pull request #3441 from input-output-hk/KtorZ/IsScriptWitnessInCtx

Add 'IsScriptWitnessInCtx'

Author: newhoggy

cardano-api/src/Cardano/Api.hs

@@ -368,6 +368,7 @@ module Cardano.Api (
     Witness(..),
     KeyWitnessInCtx(..),
     ScriptWitnessInCtx(..),
+    IsScriptWitnessInCtx(..),
     ScriptDatum(..),
     ScriptRedeemer,
     scriptWitnessScript,

cardano-api/src/Cardano/Api/Script.hs

@@ -51,6 +51,7 @@ module Cardano.Api.Script (
     Witness(..),
     KeyWitnessInCtx(..),
     ScriptWitnessInCtx(..),
+    IsScriptWitnessInCtx(..),
     ScriptDatum(..),
     ScriptRedeemer,
     scriptWitnessScript,
@@ -803,6 +804,17 @@ deriving instance Show (KeyWitnessInCtx witctx)
 deriving instance Eq   (ScriptWitnessInCtx witctx)
 deriving instance Show (ScriptWitnessInCtx witctx)
 
+class IsScriptWitnessInCtx ctx where
+  scriptWitnessInCtx :: ScriptWitnessInCtx ctx
+
+instance IsScriptWitnessInCtx WitCtxTxIn where
+  scriptWitnessInCtx = ScriptWitnessForSpending
+
+instance IsScriptWitnessInCtx WitCtxMint where
+  scriptWitnessInCtx = ScriptWitnessForMinting
+
+instance IsScriptWitnessInCtx WitCtxStake where
+  scriptWitnessInCtx = ScriptWitnessForStakeAddr
 
 -- ----------------------------------------------------------------------------
 -- Script execution units