table: have fieldnames() expose the variable and dim names plus "Prop…

…erties", instead of internal object properties; properties() too

But not `isfield()` or `isprop()`, because I don't think they're defined to work that way in Matlab.

CHANGES.txt

@@ -13,6 +13,7 @@ Version 0.4.0 (in progress)
 * Add idempotent one-arg constructor forms for string, datetime, categorical. (But not table.)
 * Add `istable`, `istimetable`, and `istabular` functions.
 * Add `NaS`, `NaC`, and `todatetime` functions.
+* Have `fieldnames (table)` expose variable and dimension names and Properties, instead of the internal implementation properties.
 * Rename `+tablicious` package to `+tblish`; merge `+octave` package into `+tblish`.
 * Move `+table_examples` package to `+tblish/+examples`.
 * Make internal-use properties on the main classes Access = private, now that the code is a little more mature.

inst/table.m

@@ -446,6 +446,26 @@ function prettyprint (this)
 
     # Structural stuff
 
+    function out = fieldnames (this)
+      # fieldnames is customize to expose the variable and dimension names as fields, and
+      # hide the real fields inside "Properties".
+      out = [this.VariableNames'; {'Properties'}; this.DimensionNames'];
+    endfunction
+
+    function out = properties (this)
+      # properties, like fieldnames, is customize to expose the variable and dimension
+      # names as fields, and hide the real fields inside "Properties".
+      out = fieldnames (this);
+      if nargout == 0
+        fprintf('Properties for class %s:\n\n', class (this));
+        for i = 1:numel (out)
+          fprintf('  %s\n', out{i});
+        endfor
+        fprintf('\n');
+        clear out
+      endif
+    endfunction
+
     ## -*- texinfo -*-
     ## @node table.varnames
     ## @deftypefn {Method} {@var{out} =} varnames (@var{obj})