)

func (f *File) walkUnexpected(x interface{}, context astContext, visit func(*File, interface{}, astContext)) {
	error_(token.NoPos, "unexpected type %T in walk", x)
	panic("unexpected type")
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return nil
}

func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
	return nil

	default:
		error_(token.NoPos, "unexpected type %T in walk", x)
		panic("unexpected type")

	case *ast.IndexListExpr:
		f.walk(&n.X, ctxExpr, visit)
		f.walk(n.Indices, ctxExpr, visit)
	}
}

func funcTypeTypeParams(n *ast.FuncType) *ast.FieldList {
	return n.TypeParams
}

func typeSpecTypeParams(n *ast.TypeSpec) *ast.FieldList {
	return n.TypeParams

	case *ast.ArrayType:
		f.walk(&n.Len, ctxExpr, visit)
		f.walk(&n.Elt, ctxType, visit)
	case *ast.StructType:
		f.walk(n.Fields, ctxField, visit)
	case *ast.FuncType:
		if tparams := funcTypeTypeParams(n); tparams != nil {
			f.walk(tparams, ctxParam, visit)
		}
		f.walk(n.Params, ctxParam, visit)
		if n.Results != nil {
			f.walk(n.Results, ctxParam, visit)
		}
	case *ast.InterfaceType: