NAME

       is - test argument to see if it is a class or an object

SYNOPSIS

       itcl::is option ?arg arg ...?
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DESCRIPTION

       The  is  command  is used to check if the argument given is a class or an object; depending on the option
       given. If the argument if a class or object, then 1 is  returned.  Otherwise,  0  is  returned.   The  is
       command also recognizes the commands wrapped in the itcl code command.

       The  option  argument determines what action is carried out by the command.  The legal options (which may
       be abbreviated) are:

       is class command
              Returns 1 if command is a class, and returns 0 otherwise.

              The fully qualified name of the class needs to be given as the command argument. So,  if  a  class
              resides in a namespace, then the namespace needs to be specified as well. So, if a class C resides
              in a namespace N, then the command should be called like:
              is N::C
                  or
              is ::N::C

       is object ?-class className? command
              Returns 1 if command is an object, and returns 0 otherwise.

              If the optional "-class" parameter is specified, then the  command  will  be  checked  within  the
              context of the class given. Note that className has to exist. If not, then an error will be given.
              So, if className is uncertain to be a class, then the programmer will need to check it's existance
              beforehand, or wrap it in a catch statement.

              So,  if c is an object in the class C, in namespace N then these are the possibilities (all return
              1):
              set obj [N::C c]
              itcl::is object N::c
              itcl::is object c
              itcl::is object $obj
              itcl::is object [itcl::code c]

KEYWORDS

       class, object