Re: Qs on obarrays

[Kevin Rodgers <ihs_4664@yahoo.com>]

Pascal Bourguignon wrote:
 > "Drew Adams" <drew.adams@oracle.com> writes:
 >>However, this does not seem to work for me:
 >>
 >>(let ((my-obarray (make-vector 7 0)))
 >>  (dolist (name my-names) (intern name my-obarray))
 >>  (all-completions "" my-obarray 'commandp))
 >>
 >>Even if all of my-names are symbol-names of commands, this always returns
 >>nil. Any idea why?
 >
 > Because symbols are objects, they have their own identity.  When a
 > symbol is used to name a function or command, it's the symbol identity
 > that's used, not its name (otherwise we would use strings to name
 > functions!).
 >
 > Try this:
 >
 > (defmacro defun-with-symbol (name args &rest body)
 >    `(defun ,(eval name) ,args ,@body))
 >
 > (let ((my-obarray (make-vector 7 0)))
 >   (defun-with-symbol (intern "insert-hello" my-obarray) ()
 >      (interactive)
 >      (insert "Hello "))
 >   (defun-with-symbol (intern "insert-world" my-obarray) ()
 >      (interactive)
 >      (insert "World! "))
 >   (funcall (intern "insert-hello" my-obarray))
 >   (funcall (intern "insert-world" my-obarray))
 >   (all-completions "" my-obarray 'commandp))

An alternative is to change just the predicate to check the standard
obarray:

(let ((my-obarray (make-vector 7 0)))
   (dolist (name my-names) (intern name my-obarray))
   (all-completions "" my-obarray
                    (lambda (symbol)
                      (commandp (intern (symbol-name symbol))))))

-- 
Kevin