syntax: anonymous vs. named functions

[Matt Price <matt.price@utoronto.ca>]

I have working code for my tab-completion problem (again thanks to
everyone for answering my painfully stupid questions).  i don't
understand, though, why attempts to write my function as an unnamed
lambda fails, but the same function succeeds when named.  the "lambda"
line commented out in tab-complete-from-function below returns an error
"test-completion: Invalid function", while the uncommented call to a
different, trivial function is successful.  cna anyone advise me why?
thanks much!

matt


(defun tab-complete-from-function (stub)
"very simple tab completion function"
  (interactive (list (completing-read "Name: "
;;				     (lambda (string)  (split-string (shell-command-to-string (concat "/home/matt/mutt-eds-query "  string)) "\n" t)) 
				      (do-completion (string)) 
				      nil t)))
  (message stub))


(defun do-completion (stub)
"minimal function"
   (split-string (shell-command-to-string (concat "/home/matt/mutt-eds-query "  stub)) "\n" t))

> > -ap
-- 
Matt Price
matt.price@utoronto.ca