% $Id$
%
% Earth System Modeling Framework
% Copyright (c) 2002-2023, University Corporation for Atmospheric Research, 
% Massachusetts Institute of Technology, Geophysical Fluid Dynamics 
% Laboratory, University of Michigan, National Centers for Environmental 
% Prediction, Los Alamos National Laboratory, Argonne National Laboratory, 
% NASA Goddard Space Flight Center.
% Licensed under the University of Illinois-NCSA License.

%\subsubsection{Restrictions and Future Work}

\begin{enumerate}

\item {\bf No optional arguments.} User-written routines called by SetServices,
and registered for Initialize, Run and Finalize, {\em must not} declare any
of the arguments as optional.

\item {\bf No Transforms.}  Components must exchange data through 
{\tt ESMF\_State} objects.  The input data are available at the time 
the component code is called, and data to be returned to another 
component are available when that code returns.  

\item {\bf No automatic unit conversions.}  The ESMF framework does not 
currently contain tools for performing unit conversions, operations that 
are fairly standard within Coupler Components.

\item {\bf No accumulator.}  The ESMF does not have an accumulator tool, to
perform time averaging of fields for coupling.  This is likely to be developed
in the near term.

\end{enumerate}
