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(Advising Functions): Don't imply one part of Emacs

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should advise another part.  Markup changes.
(Defining Advice): Move transitional para.
(Activation of Advice): Cleanup.
Explain if COMPILE is nil or negative.
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Richard M. Stallman 2005-02-26 23:49:49 +00:00
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33
lispref/advice.texi
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@ -7,15 +7,15 @@
@chapter Advising Emacs Lisp Functions
@cindex advising functions
The @dfn{advice} feature lets you add to the existing definition of a
function, by @dfn{advising the function}. This is a clean method for a
library to customize functions defined by other parts of Emacs---cleaner
The @dfn{advice} feature lets you add to the existing definition of
a function, by @dfn{advising the function}. This is a clean method
for a library to customize functions defined within Emacs---cleaner
than redefining the whole function.
@cindex piece of advice
Each function can have multiple @dfn{pieces of advice}, separately
defined. Each defined piece of advice can be @dfn{enabled} or
disabled explicitly. All the enabled pieces of advice for any given
@dfn{disabled} explicitly. All the enabled pieces of advice for any given
function actually take effect when you @dfn{activate} advice for that
function, or when you define or redefine the function. Note that
enabling a piece of advice and activating advice for a function
@ -129,6 +129,9 @@ form) to be advised. From now on, we will write just ``function'' when
describing the entity being advised, but this always includes macros and
special forms.
In place of the argument list in an ordinary definition, an advice
definition calls for several different pieces of information.
@cindex class of advice
@cindex before-advice
@cindex after-advice
@ -154,9 +157,6 @@ the pieces of advice in a particular class for a particular
@var{function}. The name allows you to refer to the piece of
advice---to redefine it, or to enable or disable it.
In place of the argument list in an ordinary definition, an advice
definition calls for several different pieces of information.
The optional @var{position} specifies where, in the current list of
advice of the specified @var{class}, this new advice should be placed.
It should be either @code{first}, @code{last} or a number that specifies
@ -332,9 +332,9 @@ replaced with the new one.
@cindex advice, activating
By default, advice does not take effect when you define it---only when
you @dfn{activate} advice for the function that was advised. However
the advice will be automatically activated if the function is defined
or redefined later. You can request the activation of advice for a
you @dfn{activate} advice for the function that was advised. However,
the advice will be activated automatically if you define or redefine
the function later. You can request the activation of advice for a
function when you define the advice, by specifying the @code{activate}
flag in the @code{defadvice}. But normally you activate the advice
for a function by calling the function @code{ad-activate} or one of
@ -353,9 +353,11 @@ are combined with the original definition to make a new definition.
@ref{Enabling Advice}.) This definition is installed, and optionally
byte-compiled as well, depending on conditions described below.
In all of the commands to activate advice, if @var{compile} is @code{t},
the command also compiles the combined definition which implements the
advice.
In all of the commands to activate advice, if @var{compile} is
@code{t} (or anything but @code{nil} or a negative number), the
command also compiles the combined definition which implements the
advice. If it is @code{nil} or a negative number, what happens
depends on @code{ad-default-compilation-action} as described below.
@deffn Command ad-activate function &optional compile
This command activates all the advice defined for @var{function}.
@ -438,9 +440,8 @@ the advice if the original definition of the advised function is
compiled or a built-in function.
This variable takes effect only if the @var{compile} argument of
@code{ad-activate} (or any of the above functions) was supplied as
@code{nil}. If that argument is non-@code{nil}, that means
to compile the advice regardless.
@code{ad-activate} (or any of the above functions) did not force
compilation.
@end defopt
If the advised definition was constructed during ``preactivation''