// already instantiated
		// For each (existing) type argument determine if it needs
		// to be substituted; i.e., if it is or contains a type parameter
		// that has a type argument for it.
		targs, updated := subst.typeList(t.TypeArgs().list())
		if updated {
			return subst.check.newAliasInstance(subst.pos, t.orig, targs, subst.ctxt)
		}

	case *Array:
		elem := subst.typOrNil(t.elem)
		if elem != t.elem {

		// already instantiated
		// For each (existing) type argument determine if it needs
		// to be substituted; i.e., if it is or contains a type parameter
		// that has a type argument for it.
		targs, updated := subst.typeList(t.TypeArgs().list())
		if updated {
			return subst.check.newAliasInstance(subst.pos, t.orig, targs, subst.ctxt)
		}

	case *Array:
		elem := subst.typOrNil(t.elem)
		if elem != t.elem {

type Alias struct {
	obj     *TypeName      // corresponding declared alias object
	orig    *Alias         // original, uninstantiated alias
	tparams *TypeParamList // type parameters, or nil
	targs   *TypeList      // type arguments, or nil
	fromRHS Type           // RHS of type alias declaration; may be an alias
	actual  Type           // actual (aliased) type; never an alias
}

type Alias struct {
	obj     *TypeName      // corresponding declared alias object
	orig    *Alias         // original, uninstantiated alias
	tparams *TypeParamList // type parameters, or nil
	targs   *TypeList      // type arguments, or nil
	fromRHS Type           // RHS of type alias declaration; may be an alias
	actual  Type           // actual (aliased) type; never an alias
}

		if w.ctxt != nil {
			w.string(strconv.Itoa(w.ctxt.getID(t)))
		}
		w.typeName(t.obj) // when hashing written for readability of the hash only
		if t.inst != nil {
			// instantiated type
			w.typeList(t.inst.targs.list())
		} else if w.ctxt == nil && t.TypeParams().Len() != 0 { // For type hashing, don't need to format the TypeParams
			// parameterized type
			w.tParamList(t.TypeParams().list())
		}

		if w.ctxt != nil {
			w.string(strconv.Itoa(w.ctxt.getID(t)))
		}
		w.typeName(t.obj) // when hashing written for readability of the hash only
		if t.inst != nil {
			// instantiated type
			w.typeList(t.inst.targs.list())
		} else if w.ctxt == nil && t.TypeParams().Len() != 0 { // For type hashing, don't need to format the TypeParams
			// parameterized type
			w.tParamList(t.TypeParams().list())
		}

		msg = "array length %s must be integer"
	}
	check.errorf(&x, InvalidArrayLen, msg, &x)
	return -1
}

// typeList provides the list of types corresponding to the incoming expression list.
// If an error occurred, the result is nil, but all list elements were type-checked.
func (check *Checker) typeList(list []ast.Expr) []Type {
	res := make([]Type, len(list)) // res != nil even if len(list) == 0
	for i, x := range list {

		msg = "array length %s must be integer"
	}
	check.errorf(&x, InvalidArrayLen, msg, &x)
	return -1
}

// typeList provides the list of types corresponding to the incoming expression list.
// If an error occurred, the result is nil, but all list elements were type-checked.
func (check *Checker) typeList(list []syntax.Expr) []Type {
	res := make([]Type, len(list)) // res != nil even if len(list) == 0
	for i, x := range list {

	}
	return x
}

// typeList parses a non-empty, comma-separated list of types,
// optionally followed by a comma. If strict is set to false,
// the first element may also be a (non-type) expression.
// If there is more than one argument, the result is a *ListExpr.
// The comma result indicates whether there was a (separating or
// trailing) comma.
//
// typeList = arg { "," arg } [ "," ] .

pkg go/types, method (*Alias) Origin() *Alias #67143
pkg go/types, method (*Alias) Rhs() Type #66559
pkg go/types, method (*Alias) SetTypeParams([]*TypeParam) #67143
pkg go/types, method (*Alias) TypeArgs() *TypeList #67143
pkg go/types, method (*Alias) TypeParams() *TypeParamList #67143
pkg go/types, method (*Func) Signature() *Signature #65772