      \fitem{loadvalue}(\emph{file}:string) : read a file produced by a
      call to the function \atvar{savevalue} and returns the value that was
      saved. If something goes wrong, an undefined value is returned.
      See also function \atvar{dump}, \atvar{dumpvar} and \atvar{loadvar}.

      Because the variables are supposed to have their saved values right
      after the call to \atvar{loadvar}, we deliberately use a synchronous
      scheme where the function returns after having completed all the
      initializations.
      %% 
      A call to this function may take a noticeable time depending on the
      size of the values to store in the dump file. While this time is
      usually negligible, loading a tab of $10\,000$ integers represents a
      file of size about $60$\,Kb and takes between $2$\,ms and $3$\,ms.
      %% 
      This computational cost may have a negative impact on the audio
      processing in heavy cases. However, the intended use of
      \atvar{loadvalue} and \atvar{loadvar} functions is to restore a
      ``preset'' at isolated places like the beginning of the score or
      between musical sequences, a usage where this cost should have no
      impact.
      %% 
      Notice that saving a value or variables is done
      \emph{asynchronously} and does not disturb the ``main''
      computation. See the remarks of function \atvar{dump}. 



      %%% -------------------------------------------------------

