@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998 Free Software Foundation, Inc.
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999
+@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/sequences
-@node Sequences Arrays Vectors, Symbols, Lists, Top
+@node Sequences Arrays Vectors, Hash Tables, Lists, Top
@chapter Sequences, Arrays, and Vectors
@cindex sequence
sequence.
@defun sequencep object
-Returns @code{t} if @var{object} is a list, vector, or
-string, @code{nil} otherwise.
+Returns @code{t} if @var{object} is a list, vector,
+string, bool-vector, or char-table, @code{nil} otherwise.
@end defun
@defun length sequence
@cindex list length
@cindex vector length
@cindex sequence length
+@cindex char-table length
This function returns the number of elements in @var{sequence}. If
@var{sequence} is a cons cell that is not a list (because the final
@sc{cdr} is not @code{nil}), a @code{wrong-type-argument} error is
-signaled.
+signaled. For a char-table, the value returned is always one more
+than the maximum Emacs character code.
@xref{List Elements}, for the related function @code{safe-length}.
@end example
@end defun
+@defun string-bytes string
+@cindex string, number of bytes
+This function returns the number of bytes in @var{string}.
+If @var{string} is a multibyte string, this is greater than
+@code{(length @var{string})}.
+@end defun
+
@defun elt sequence index
@cindex elements of sequences
This function returns the element of @var{sequence} indexed by
@xref{Text Properties}.
See also @code{append} in @ref{Building Lists}, @code{concat} in
-@ref{Creating Strings}, and @code{vconcat} in @ref{Vectors}, for others
-ways to copy sequences.
+@ref{Creating Strings}, and @code{vconcat} in @ref{Vector Functions},
+for other ways to copy sequences.
@example
@group
Emacs defines four types of array, all one-dimensional: @dfn{strings},
@dfn{vectors}, @dfn{bool-vectors} and @dfn{char-tables}. A vector is a
general array; its elements can be any Lisp objects. A string is a
-specialized array; its elements must be characters (i.e., integers
-between 0 and 255). Each type of array has its own read syntax.
+specialized array; its elements must be characters. Each type of array
+has its own read syntax.
@xref{String Type}, and @ref{Vector Type}.
All four kinds of array share these characteristics:
@end group
@group
(aref "abcdefg" 1)
- @result{} 98 ; @r{@samp{b} is @sc{ASCII} code 98.}
+ @result{} 98 ; @r{@samp{b} is @acronym{ASCII} code 98.}
@end group
@end example
@end example
If @var{array} is a string and @var{object} is not a character, a
-@code{wrong-type-argument} error results. If @var{array} is a string
-and @var{object} is character, but @var{object} does not use the same
-number of bytes as the character currently stored in @code{(aref
-@var{object} @var{index})}, that is also an error. @xref{Splitting
-Characters}.
+@code{wrong-type-argument} error results. The function converts a
+unibyte string to multibyte if necessary to insert a character.
@end defun
@defun fillarray array object
arguments. This is a special feature to make it easy to access the entire
contents of a byte-code function object. @xref{Byte-Code Objects}.
-The @code{vconcat} function also allows integers as arguments. It
-converts them to strings of digits, making up the decimal print
-representation of the integer, and then uses the strings instead of the
-original integers. @strong{Don't use this feature; we plan to eliminate
-it. If you already use this feature, change your programs now!} The
-proper way to convert an integer to a decimal number in this way is with
-@code{format} (@pxref{Formatting Strings}) or @code{number-to-string}
-(@pxref{String Conversion}).
+In Emacs versions before 21, the @code{vconcat} function allowed
+integers as arguments, converting them to strings of digits, but that
+feature has been eliminated. The proper way to convert an integer to
+a decimal number in this way is with @code{format} (@pxref{Formatting
+Strings}) or @code{number-to-string} (@pxref{String Conversion}).
For other concatenation functions, see @code{mapconcat} in @ref{Mapping
Functions}, @code{concat} in @ref{Creating Strings}, and @code{append}
@dfn{extra slots} in the char-table.
@cindex parent of char-table
- A char-table can have a @dfn{parent}. which is another char-table. If
+ A char-table can have a @dfn{parent}, which is another char-table. If
it does, then whenever the char-table specifies @code{nil} for a
particular character @var{c}, it inherits the value specified in the
parent. In other words, @code{(aref @var{char-table} @var{c})} returns
whenever the char-table does not specify any other non-@code{nil} value.
@defun make-char-table subtype &optional init
-@tindex make-char-table
Return a newly created char-table, with subtype @var{subtype}. Each
element is initialized to @var{init}, which defaults to @code{nil}. You
cannot alter the subtype of a char-table after the char-table is
@end defun
@defun char-table-p object
-@tindex char-table-p
This function returns @code{t} if @var{object} is a char-table,
otherwise @code{nil}.
@end defun
@defun char-table-subtype char-table
-@tindex char-table-subtype
This function returns the subtype symbol of @var{char-table}.
@end defun
@defun set-char-table-default char-table new-default
-@tindex set-char-table-default
This function sets the default value of @var{char-table} to
@var{new-default}.
@end defun
@defun char-table-parent char-table
-@tindex char-table-parent
This function returns the parent of @var{char-table}. The parent is
always either @code{nil} or another char-table.
@end defun
@defun set-char-table-parent char-table new-parent
-@tindex set-char-table-parent
This function sets the parent of @var{char-table} to @var{new-parent}.
@end defun
@defun char-table-extra-slot char-table n
-@tindex char-table-extra-slot
This function returns the contents of extra slot @var{n} of
@var{char-table}. The number of extra slots in a char-table is
determined by its subtype.
@end defun
@defun set-char-table-extra-slot char-table n value
-@tindex set-char-table-extra-slot
This function stores @var{value} in extra slot @var{n} of
@var{char-table}.
@end defun
it can also specify a value for an entire character set.
@defun char-table-range char-table range
-@tindex char-table-range
This returns the value specified in @var{char-table} for a range of
characters @var{range}. Here are the possibilities for @var{range}:
@end defun
@defun set-char-table-range char-table range value
-@tindex set-char-table-range
-This function set the value in @var{char-table} for a range of
+This function sets the value in @var{char-table} for a range of
characters @var{range}. Here are the possibilities for @var{range}:
@table @asis
@end defun
@defun map-char-table function char-table
-@tindex map-char-table
This function calls @var{function} for each element of @var{char-table}.
@var{function} is called with two arguments, a key and a value. The key
is a possible @var{range} argument for @code{char-table-range}---either
here is how to examine each element of the syntax table:
@example
-(map-char-table
- #'(lambda (key value)
- (setq accumulator
- (cons (list key value) accumulator)))
- (syntax-table))
+(let (accumulator)
+ (map-char-table
+ #'(lambda (key value)
+ (setq accumulator
+ (cons (list key value) accumulator)))
+ (syntax-table))
+ accumulator)
@result{}
((475008 nil) (474880 nil) (474752 nil) (474624 nil)
... (5 (3)) (4 (3)) (3 (3)) (2 (3)) (1 (3)) (0 (3)))
of arrays.
@defun make-bool-vector length initial
-@tindex make-bool-vector
-Return a new book-vector of @var{length} elements,
+Return a new bool-vector of @var{length} elements,
each one initialized to @var{initial}.
@end defun
@defun bool-vector-p object
-@tindex bool-vector-p
This returns @code{t} if @var{object} is a bool-vector,
and @code{nil} otherwise.
@end defun
+ Here is an example of creating, examining, and updating a
+bool-vector. Note that the printed form represents up to 8 boolean
+values as a single character.
+
+@example
+(setq bv (make-bool-vector 5 t))
+ @result{} #&5"^_"
+(aref bv 1)
+ @result{} t
+(aset bv 3 nil)
+ @result{} nil
+bv
+ @result{} #&5"^W"
+@end example
+
+@noindent
+These results make sense because the binary codes for control-_ and
+control-W are 11111 and 10111, respectively.
+
+@ignore
+ arch-tag: fcf1084a-cd29-4adc-9f16-68586935b386
+@end ignore
HCoop / bpt / emacs.git / blobdiff