Move the logic of getting ctor params to trees

Author: chengluyu

hkmc2/shared/src/main/scala/hkmc2/codegen/Lowering.scala

@@ -220,7 +220,7 @@ class Lowering(using TL, Raise, Elaborator.State):
                 subTerm(trm): st =>
                   val args = args0.getOrElse(Nil)
                   val clsParams = cls match
-                    case cls: ClassSymbol => cls.params
+                    case cls: ClassSymbol => cls.tree.params
                     case _: ModuleSymbol => Nil
                   assert(args0.isEmpty || clsParams.length === args.length)
                   def mkArgs(args: Ls[(LocalSymbol & NamedSymbol) -> BlockLocalSymbol])(using Subst): Case -> Block = args match

hkmc2/shared/src/main/scala/hkmc2/semantics/Symbol.scala

@@ -125,9 +125,7 @@ class TermSymbol(val k: TermDefKind, val owner: Opt[InnerSymbol], val id: Tree.I
   override def toString: Str = s"${owner.getOrElse("")}.${id.name}"
 
 
-sealed trait CtorSymbol extends Symbol:
-  /** Get parameter symbols. */
-  def params: Ls[LocalSymbol & NamedSymbol] = Nil
+sealed trait CtorSymbol extends Symbol
 
 case class Extr(isTop: Bool) extends CtorSymbol:
   def nme: Str = if isTop then "Top" else "Bot"
@@ -161,13 +159,6 @@ class ClassSymbol(val tree: Tree.TypeDef, val id: Tree.Ident)
   def arity: Int = defn match
     case S(d) => d.paramsOpt.fold(0)(_.length)
     case N => tree.paramLists.headOption.fold(0)(_.fields.length)
-  /** Get parameter symbols. Create new symbols if not elaborated. */
-  override lazy val params: Ls[LocalSymbol & NamedSymbol] = defn match
-    case S(d) => d.paramsOpt.fold(Nil)(_.map(_._2))
-    case N => tree.paramLists.headOption.fold(Nil): tup =>
-      tup.fields.iterator.flatMap(_.param).map:
-        case (id, _) => TermSymbol(ParamBind, S(this), id)
-      .toList
 
 class ModuleSymbol(val tree: Tree.TypeDef, val id: Tree.Ident)
     extends MemberSymbol[ModuleDef] with CtorSymbol with InnerSymbol:

hkmc2/shared/src/main/scala/hkmc2/syntax/Tree.scala

@@ -288,4 +288,9 @@ trait TypeDefImpl extends TypeOrTermDef:
     case _ =>
       Map.empty
 
+  lazy val params: Ls[semantics.TermSymbol] =
+    this.paramLists.headOption.fold(Nil): tup =>
+      tup.fields.iterator.flatMap(_.param).map:
+        case (id, _) => semantics.TermSymbol(ParamBind, symbol.asClsLike, id)
+      .toList