fix: Avoid generating names in constructor field which clash with params

Signed-off-by: George Thomas <[email protected]>

Author: georgefst

primer/src/Primer/Action/Available.hs

@@ -81,6 +81,7 @@ import Primer.Primitives (tChar, tInt)
 import Primer.Questions (
   generateNameExpr,
   generateNameTy,
+  generateNameTyAvoiding,
   variablesInScopeExpr,
   variablesInScopeTy,
  )
@@ -490,8 +491,8 @@ options typeDefs defs cxt level def0 sel0 = \case
             Left zE -> generateNameExpr typeOrKind zE
             Right zT -> generateNameTy typeOrKind zT
         SelectionTypeDef sel -> do
-          (_, zT) <- conField sel
-          pure $ generateNameTy typeOrKind zT
+          (def, zT) <- conField sel
+          pure $ generateNameTyAvoiding (unLocalName . fst <$> astTypeDefParameters def) typeOrKind zT
     varsInScope = case sel0 of
       SelectionDef sel -> do
         nodeSel <- sel.node

primer/src/Primer/Questions.hs

@@ -10,6 +10,7 @@ module Primer.Questions (
   ShadowedVarsTy (..), -- only exported for testing
   generateNameExpr,
   generateNameTy,
+  generateNameTyAvoiding,
   uniquify,
 ) where
 
@@ -100,9 +101,18 @@ generateNameTy ::
   Either (Maybe (Type' ())) (Maybe Kind) ->
   TypeZip ->
   m [Name]
+generateNameTy = generateNameTyAvoiding []
+
+generateNameTyAvoiding ::
+  MonadReader Cxt m =>
+  [Name] ->
+  Either (Maybe (Type' ())) (Maybe Kind) ->
+  TypeZip ->
+  m [Name]
 -- It doesn't really make sense to ask for a term variable (Left) here, but
 -- it doesn't harm to support it
-generateNameTy tk z = uniquifyMany <$> mkAvoidForFreshNameTy z <*> baseNames tk
+generateNameTyAvoiding avoiding tk z =
+  uniquifyMany <$> ((Set.fromList avoiding <>) <$> mkAvoidForFreshNameTy z) <*> baseNames tk
 
 baseNames ::
   MonadReader Cxt m =>