member* assoc* rassoc* get*
remove* delete* mapcar* sort*
floor* ceiling* truncate* round*
-mod* rem* random* last*
+mod* rem* random*
@end example
Internal function and variable names in the package are prefixed
@example
eql floatp-safe endp
evenp oddp plusp minusp
-butlast nbutlast caaar .. cddddr
+caaar .. cddddr
list* ldiff rest first .. tenth
copy-list subst mapcar* [2]
adjoin [3] acons pairlis pop [4]
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
@end defun
@defun mapc function seq &rest more-seqs
-This function is like @code{mapcar*}, except that the values
-returned by @var{function} are ignored and thrown away rather
-than being collected into a list. The return value of @code{mapc}
-is @var{seq}, the first sequence.
+This function is like @code{mapcar*}, except that the values returned
+by @var{function} are ignored and thrown away rather than being
+collected into a list. The return value of @code{mapc} is @var{seq},
+the first sequence. This function is more general than the Emacs
+primitive @code{mapc}.
@end defun
@defun mapl function list &rest more-lists
The functions described here operate on lists.
@menu
-* List Functions:: `caddr', `first', `last*', `list*', etc.
+* List Functions:: `caddr', `first', `list*', etc.
* Substitution of Expressions:: `subst', `sublis', etc.
* Lists as Sets:: `member*', `adjoin', `union', etc.
* Association Lists:: `assoc*', `rassoc*', `acons', `pairlis'
@code{length} function would get stuck if given a circular list.)
@end defun
-@defun last* x &optional n
-This function returns the last cons, or the @var{n}th-to-last cons,
-of the list @var{x}. If @var{n} is omitted it defaults to 1.
-The ``last cons'' means the first cons cell of the list whose
-@code{cdr} is not another cons cell. (For normal lists, the
-@code{cdr} of the last cons will be @code{nil}.) This function
-returns @code{nil} if @var{x} is @code{nil} or shorter than
-@var{n}. Note that the last @emph{element} of the list is
-@code{(car (last @var{x}))}.
-
-The Emacs function @code{last} does the same thing
-except that it does not handle the optional argument @var{n}.
-@end defun
-
-@defun butlast x &optional n
-This function returns the list @var{x} with the last element,
-or the last @var{n} elements, removed. If @var{n} is greater
-than zero it makes a copy of the list so as not to damage the
-original list. In general, @code{(append (butlast @var{x} @var{n})
-(last @var{x} @var{n}))} will return a list equal to @var{x}.
-@end defun
-
-@defun nbutlast x &optional n
-This is a version of @code{butlast} that works by destructively
-modifying the @code{cdr} of the appropriate element, rather than
-making a copy of the list.
-@end defun
-
@defun list* arg &rest others
This function constructs a list of its arguments. The final
argument becomes the @code{cdr} of the last cell constructed.
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
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}.
HCoop / bpt / emacs.git / blobdiff