# HG changeset patch
# User Rik <rik@octave.org>
# Date 1682434229 25200
# Node ID d77b987a7e0d618820c421b1b8b171d5612f5a29
# Parent  17a09d2bbe0f98b7a6518ceddba234fceba3ccaf
Provide more informative error messages for various bad calling forms to set() (bug #64072)

* graphics.cc (graphics_object::set (const octave_value_list& args)): Clarify
summary of function.  Remove unnecessary FIXME.  Move BIST tests to below Fset
function.
* graphics.cc (Fset): Check if first argument is a string and process as
NAME/VALUE pair.  Provide explicit error message about what is wrong if only
NAME is given and no matching VALUE.  Directly call set_value_or_default()
rather than forming a 2-element octave_value_list and calling set() function
which accepts octave_value_list objects.  Provide explicit error message if
cell array of PROPERTIES is given with no following cell array of VALUES.
If input validation fails just report "invalid syntax" rather than trying
to suggest which input was at fault.

diff -r 17a09d2bbe0f -r d77b987a7e0d libinterp/corefcn/graphics.cc
--- a/libinterp/corefcn/graphics.cc	Sun Apr 23 11:08:16 2023 +0200
+++ b/libinterp/corefcn/graphics.cc	Tue Apr 25 07:50:29 2023 -0700
@@ -2550,7 +2550,7 @@
   return m;
 }
 
-// Set properties given as a cs-list of name, value pairs.
+// Set property given as either cs-list of name/value pairs or a struct.
 
 void
 graphics_object::set (const octave_value_list& args)
@@ -2562,9 +2562,6 @@
 
   for (int i = 0; i < nargin; )
     {
-      // FIXME: Should this if branch be eliminated and determination of
-      // struct input be determined earlier such that the correct set(...)
-      // function is invoked by the compiler?
       if (args(i).isstruct ())
         {
           set (args(i).map_value ());
@@ -2679,41 +2676,6 @@
 }
 
 /*
-## test set ticklabels for compatibility
-%!test
-%! hf = figure ("visible", "off");
-%! set (gca (), "xticklabel", [0, 0.2, 0.4, 0.6, 0.8, 1]);
-%! xticklabel = get (gca (), "xticklabel");
-%! close (hf);
-%! assert (class (xticklabel), "char");
-%! assert (size (xticklabel), [6, 3]);
-
-%!test
-%! hf = figure ("visible", "off");
-%! set (gca (), "xticklabel", "0|0.2|0.4|0.6|0.8|1");
-%! xticklabel = get (gca (), "xticklabel");
-%! close (hf);
-%! assert (class (xticklabel), "char");
-%! assert (size (xticklabel), [6, 3]);
-
-%!test
-%! hf = figure ("visible", "off");
-%! set (gca (), "xticklabel", ["0 "; "0.2"; "0.4"; "0.6"; "0.8"; "1 "]);
-%! xticklabel = get (gca (), "xticklabel");
-%! close (hf);
-%! assert (class (xticklabel), "char");
-%! assert (size (xticklabel), [6, 3]);
-
-%!test
-%! hf = figure ("visible", "off");
-%! set (gca (), "xticklabel", {"0", "0.2", "0.4", "0.6", "0.8", "1"});
-%! xticklabel = get (gca (), "xticklabel");
-%! close (hf);
-%! assert (class (xticklabel), "cell");
-%! assert (size (xticklabel), [6, 1]);
-*/
-
-/*
 ## test set with struct arguments
 %!test
 %! hf = figure ("visible", "off");
@@ -12261,8 +12223,19 @@
       // Loop over input arguments
       for (octave_idx_type i = 1; i < args.length (); )
         {
-          if ((i < nargin - 1) && args(i).iscellstr () && args(i+1).iscell ())
-            {
+          if (args(i).is_string ())
+            {
+              if (i == nargin - 1)
+                error ("set: PROPERTY name must be followed by a VALUE");
+              const caseless_str pname = args(i).string_value ();
+              const octave_value val = args(i+1);
+              go.set_value_or_default (pname, val);
+              i += 2;
+            }
+          else if (args(i).iscellstr ())
+            {
+              if ((i == nargin - 1) || ! args(i+1).iscell ())
+                error ("set: cell array of PROPERTIES must be followed by cell array of VALUES");
               if (args(i+1).cell_value ().rows () == 1)
                 go.set (args(i).cellstr_value (), args(i+1).cell_value (), 0);
               else if (hcv.numel () == args(i+1).cell_value ().rows ())
@@ -12275,17 +12248,12 @@
               i += 2;
             }
           else if (args(i).isstruct ())
-          {
-            go.set (args(i).map_value ());
-            i += 1;
-          }
-          else if (i < nargin - 1)
-          {
-            go.set (args.slice (i, 2));
-            i += 2;
-          }
+            {
+              go.set (args(i).map_value ());
+              i += 1;
+            }
           else
-            error ("set: invalid syntax at input #%" OCTAVE_IDX_TYPE_FORMAT, i+1);
+            error ("set: invalid syntax");
         }
 
       request_drawnow = true;
@@ -12297,6 +12265,41 @@
   return retval;
 }
 
+/*
+## test setting ticklabels for compatibility
+%!test
+%! hf = figure ("visible", "off");
+%! set (gca (), "xticklabel", [0, 0.2, 0.4, 0.6, 0.8, 1]);
+%! xticklabel = get (gca (), "xticklabel");
+%! close (hf);
+%! assert (class (xticklabel), "char");
+%! assert (size (xticklabel), [6, 3]);
+
+%!test
+%! hf = figure ("visible", "off");
+%! set (gca (), "xticklabel", "0|0.2|0.4|0.6|0.8|1");
+%! xticklabel = get (gca (), "xticklabel");
+%! close (hf);
+%! assert (class (xticklabel), "char");
+%! assert (size (xticklabel), [6, 3]);
+
+%!test
+%! hf = figure ("visible", "off");
+%! set (gca (), "xticklabel", ["0 "; "0.2"; "0.4"; "0.6"; "0.8"; "1 "]);
+%! xticklabel = get (gca (), "xticklabel");
+%! close (hf);
+%! assert (class (xticklabel), "char");
+%! assert (size (xticklabel), [6, 3]);
+
+%!test
+%! hf = figure ("visible", "off");
+%! set (gca (), "xticklabel", {"0", "0.2", "0.4", "0.6", "0.8", "1"});
+%! xticklabel = get (gca (), "xticklabel");
+%! close (hf);
+%! assert (class (xticklabel), "cell");
+%! assert (size (xticklabel), [6, 1]);
+*/
+
 static std::string
 get_graphics_object_type (double val)
 {