**''FUNCTION''**

Function form expects one argument, most typically a symbol. It will look up a function object associated with the symbol. The ''FUNCTION'' form is related to quoting and has the special character ''#'%%%%'' (sharp-quote). A symbol in LabLISP can name a variable and a function at the same time - like in Common LISP, there are separate namespaces for values and functions. A symbol in an expression is evaluated to the function if it stands first in the form, otherwise it is evaluated to the value as variable. With sharp-quoting a symbol, we force evalation to the function named by it.

Following example should make this more clear

<code lisp>
>(setq f 3)      ; we defined variable F, with value 3
3

>(defun f () 42)  ; we defined function F, with no parameters, returning 42
F
</code>

Now we have symbol F which has both value and function, let's see how it evaluates

<code lisp>
>f                ; we are evaluating just symbol outside of form
3

>(+ 1 f)          ; F will be evaluated to value 3
4

>(f)              ; function call to F
42

>'f               ; quoting F
F

>#'f              ; (FUNCTION F) call returns the function object itself
#<user-defined function F>
</code>

See also functions ''SYMBOL-VALUE'', ''SYMBOL-FUNCTION'' in the [[ch2_3_pack_sym|Package and symbol operations]] section, and the applicative functions ''FUNCALL'' and ''APPLY'' in [[ch2_3_manage|Management]] section.

See also the future section 1.3.4 for more details.