maint: Refactor general/isXXX.m scripts to put input validation first. * general/isdir.m, general/isequal.m, general/isequalwithequalnans.m, general/isscalar.m, general/issquare.m, general/isvector.m: Refactor code to put input validation first. * general/iscolumn.m, general/isrow.m : Remove useless initialization of output variable. * general/isa.m: Add additional tests for various classes.

--- a/scripts/general/isscalar.m	Wed Apr 13 09:22:38 2011 -0700
+++ b/scripts/general/isscalar.m	Wed Apr 13 09:32:10 2011 -0700
@@ -26,12 +26,12 @@
 
 function retval = isscalar (x)
 
-  if (nargin == 1)
-    retval = numel (x) == 1;
-  else
+  if (nargin != 1)
     print_usage ();
   endif
 
+  retval = numel (x) == 1;
+
 endfunction
 
 %!assert(isscalar (1));