// 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 {

		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 {

}

// instance holds information that is only necessary for instantiated named
// types.
type instance struct {
	orig            *Named    // original, uninstantiated type
	targs           *TypeList // type arguments
	expandedMethods int       // number of expanded methods; expandedMethods <= len(orig.methods)
	ctxt            *Context  // local Context; set to nil after full expansion
}

}

// instance holds information that is only necessary for instantiated named
// types.
type instance struct {
	orig            *Named    // original, uninstantiated type
	targs           *TypeList // type arguments
	expandedMethods int       // number of expanded methods; expandedMethods <= len(orig.methods)
	ctxt            *Context  // local Context; set to nil after full expansion
}

	// targs and xlist are the type arguments and corresponding type expressions, or nil.
	var targs []Type
	var xlist []syntax.Expr
	if inst != nil {
		xlist = syntax.UnpackListExpr(inst.Index)
		targs = check.typeList(xlist)
		if targs == nil {
			x.mode = invalid
			return nil, nil
		}
		assert(len(targs) == len(xlist))
	}

	// Check the number of type arguments (got) vs number of type parameters (want).

	// targs and xlist are the type arguments and corresponding type expressions, or nil.
	var targs []Type
	var xlist []ast.Expr
	if ix != nil {
		xlist = ix.Indices
		targs = check.typeList(xlist)
		if targs == nil {
			x.mode = invalid
			return nil, nil
		}
		assert(len(targs) == len(xlist))
	}

	// Check the number of type arguments (got) vs number of type parameters (want).