Translator

[Reti@WESER.sreti.symbolics.com (Kalman Reti)]

    Date: Fri, 14 Sep 90 21:22 EDT
    From: barmar@Think.COM (Barry Margolin)

	Date: Fri, 14 Sep 90 20:20 EDT
	From: RWK@fuji.ila.com (Robert W. Kerns)

	APPLY does not use hash tables.  However, for maximum speed and
	minimum paging, you should pass actual functions, and not
	symbols, to apply.  I.e

	(setf (gethash name *name->function-table*) #'rewrite-function)
	not
	(setf (gethash name *name->function-table*) 'rewrite-function)

    However, you should note that this mechanism can be a pain during
    development.  If you redefine REWRITE-FUNCTION after storing the
    function in the table the first way, you will continue to call the old
    definition when you extract it, while the second form will cause the
    current function binding of the symbol always to be used.

    I campaigned (and won) for automatic coercion of symbols to functions by
    APPLY, FUNCALL, etc. in X3J13 for precisely this reason.  I've seen
    users burned many times when they store a function in a data structure,
    load a patch file that fixes a bug in the function, yet the bug still
    appears.
An intermediate strategy is to store the location of the function cell
(LOCF #'rewrite-function) and then use LOCATION-CONTENTS in conjunction with
the APPLY or FUNCALL.  This will get the new definition when a redefinition
occurs, but will avoid the paging overhead of having to reference the symbol
(which is likely to be far away from the function cell).

    I also applaud Genera 8.0's enhancement to the printed representation of
    functions: a function object that isn't the current binding of its name
    symbol has "(Superceded)" in the printed rep.
I hope, it has "(Superseded)" which is the correct spelling.  ;->  (I just checked,
it does.)

						    barmar