display matrix values in GUI workspace viewer (bug #40499) * pr-output.h, pr-output.cc (octave_print_internal): Provide dummy versions for char and octave_value objects. (octave_print_internal (ostream&, double, bool), octave_print_internal (ostream&, const Complex&, bool)): Handle print_as_read_syntax. * ov-base-mat.h, ov-base-mat.cc (octave_base_mat<MT>::short_disp): New function. * ov-cell.h, ov-cell.cc (octave_cell::short_disp): New function.

--- a/libinterp/octave-value/ov-base-mat.h
+++ b/libinterp/octave-value/ov-base-mat.h
@@ -157,6 +157,8 @@
 
   void print_info (std::ostream& os, const std::string& prefix) const;
 
+  std::string short_disp (void) const;
+
   MT& matrix_ref (void)
   {
     clear_cached_info ();