Re: method-lambda and apply-method-lambda

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: Mon, 11 Apr 88 08:58:35 -0700
    From: kempf@Sun.COM

    >    APPLY-METHOD method next-method-info &REST arguments

    I don't think this generic function is really necessary, 
    since APPLY, being itself
    implementation dependent, could be modified to do the right thing given
    a method function. 

Jim, I think you must have missed the point.  The problem isn't that what
APPLY does is implementation-dependent, but that the arguments to be passed
to APPLY are implementation-dependent.  The most obvious case is the
next-method-info info; there is no way for APPLY to deduce this from the
other arguments, is there?  If there is a way, I might change my mind on
suggesting a separate APPLY-METHOD primitive, but if there isn't a way,
we have to have that primitive so that the caller can supply the information.

		       Some implementations of APPLY 
    already must differentiate based on whether the function object is a closure
    or not, since in the former case, the lexical environment must be
    modified to reflect the lexical environment of the closure, so the
    additional case of a method function is probably nothing new.
    However, it might be useful for metaobject programmers who want a hook
    for a metaclass specific way of applying a method. In that case, I think
    the NEXT-METHOD-INFO argument could be dropped, since the concept of
    a next method is specific to STANDARD-METHOD. 

I disagree.  I think CALL-NEXT-METHOD should be available to all classes
of methods that want it; I don't think it should be something magic for
standard-method.

						  The method metaclass method
    for this generic function would then implement any special processing
    for changing control flow.

I don't think I understand this last sentence; do you have a specific proposal?