Commit a9c498a5 authored by Stefan Monnier's avatar Stefan Monnier
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Remove obsolete warnings about use of memq for keyword args.

parent 4faaa994
......@@ -498,19 +498,6 @@ accepts other keyword arguments which are passed on to the
keep both @code{find-thing} and @code{member*} from complaining
about each others' keywords in the arguments.
As a (significant) performance optimization, this package
implements the scan for keyword arguments by calling @code{memq}
to search for keywords in a ``rest'' argument. Technically
speaking, this is incorrect, since @code{memq} looks at the
odd-numbered values as well as the even-numbered keywords.
The net effect is that if you happen to pass a keyword symbol
as the @emph{value} of another keyword argument, where that
keyword symbol happens to equal the name of a valid keyword
argument of the same function, then the keyword parser will
become confused. This minor bug can only affect you if you
use keyword symbols as general-purpose data in your program;
this practice is strongly discouraged in Emacs Lisp.
The fifth section of the argument list consists of @dfn{auxiliary
variables}. These are not really arguments at all, but simply
variables which are bound to @code{nil} or to the specified
......@@ -4991,13 +4978,7 @@ have built-in compiler macros to optimize them in common cases.
Common Lisp compliance has in general not been sacrificed for the
sake of efficiency. A few exceptions have been made for cases
where substantial gains were possible at the expense of marginal
incompatibility. One example is the use of @code{memq} (which is
treated very efficiently by the byte-compiler) to scan for keyword
arguments; this can become confused in rare cases when keyword
symbols are used as both keywords and data values at once. This
is extremely unlikely to occur in practical code, and the use of
@code{memq} allows functions with keyword arguments to be nearly
as fast as functions that use @code{&optional} arguments.
incompatibility.
The Common Lisp standard (as embodied in Steele's book) uses the
phrase ``it is an error if'' to indicate a situation which is not
......@@ -5057,13 +5038,6 @@ which understand full-featured argument lists. The @code{&whole}
keyword does not work in @code{defmacro} argument lists (except
inside recursive argument lists).
In order to allow an efficient implementation, keyword arguments use
a slightly cheesy parser which may be confused if a keyword symbol
is passed as the @emph{value} of another keyword argument.
(Specifically, @code{(memq :@var{keyword} @var{rest-of-arguments})}
is used to scan for @code{:@var{keyword}} among the supplied
keyword arguments.)
The @code{eql} and @code{equal} predicates do not distinguish
between IEEE floating-point plus and minus zero. The @code{equalp}
predicate has several differences with Common Lisp; @pxref{Predicates}.
......
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