[Emacs-diffs] Changes to streams.texi

[Glenn Morris]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Glenn Morris <gm>       07/09/06 04:23:11

Index: streams.texi
===================================================================
RCS file: streams.texi
diff -N streams.texi
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ streams.texi        6 Sep 2007 04:23:11 -0000       1.1
@@ -0,0 +1,837 @@
address@hidden -*-texinfo-*-
address@hidden This is part of the GNU Emacs Lisp Reference Manual.
address@hidden Copyright (C) 1990, 1991, 1992, 1993, 1994, 1998, 1999, 2001, 
2002,
address@hidden   2003, 2004, 2005, 2006, 2007  Free Software Foundation, Inc.
address@hidden See the file elisp.texi for copying conditions.
address@hidden ../info/streams
address@hidden Read and Print, Minibuffers, Debugging, Top
address@hidden  node-name,  next,  previous,  up
address@hidden Reading and Printing Lisp Objects
+
+  @dfn{Printing} and @dfn{reading} are the operations of converting Lisp
+objects to textual form and vice versa.  They use the printed
+representations and read syntax described in @ref{Lisp Data Types}.
+
+  This chapter describes the Lisp functions for reading and printing.
+It also describes @dfn{streams}, which specify where to get the text (if
+reading) or where to put it (if printing).
+
address@hidden
+* Streams Intro::     Overview of streams, reading and printing.
+* Input Streams::     Various data types that can be used as input streams.
+* Input Functions::   Functions to read Lisp objects from text.
+* Output Streams::    Various data types that can be used as output streams.
+* Output Functions::  Functions to print Lisp objects as text.
+* Output Variables::  Variables that control what the printing functions do.
address@hidden menu
+
address@hidden Streams Intro
address@hidden Introduction to Reading and Printing
address@hidden Lisp reader
address@hidden printing
address@hidden reading
+
+  @dfn{Reading} a Lisp object means parsing a Lisp expression in textual
+form and producing a corresponding Lisp object.  This is how Lisp
+programs get into Lisp from files of Lisp code.  We call the text the
address@hidden syntax} of the object.  For example, the text @samp{(a .@: 5)}
+is the read syntax for a cons cell whose @sc{car} is @code{a} and whose
address@hidden is the number 5.
+
+  @dfn{Printing} a Lisp object means producing text that represents that
+object---converting the object to its @dfn{printed representation}
+(@pxref{Printed Representation}).  Printing the cons cell described
+above produces the text @samp{(a .@: 5)}.
+
+  Reading and printing are more or less inverse operations: printing the
+object that results from reading a given piece of text often produces
+the same text, and reading the text that results from printing an object
+usually produces a similar-looking object.  For example, printing the
+symbol @code{foo} produces the text @samp{foo}, and reading that text
+returns the symbol @code{foo}.  Printing a list whose elements are
address@hidden and @code{b} produces the text @samp{(a b)}, and reading that
+text produces a list (but not the same list) with elements @code{a}
+and @code{b}.
+
+  However, these two operations are not precisely inverse to each other.
+There are three kinds of exceptions:
+
address@hidden @bullet
address@hidden
+Printing can produce text that cannot be read.  For example, buffers,
+windows, frames, subprocesses and markers print as text that starts
+with @samp{#}; if you try to read this text, you get an error.  There is
+no way to read those data types.
+
address@hidden
+One object can have multiple textual representations.  For example,
address@hidden and @samp{01} represent the same integer, and @samp{(a b)} and
address@hidden(a .@: (b))} represent the same list.  Reading will accept any of
+the alternatives, but printing must choose one of them.
+
address@hidden
+Comments can appear at certain points in the middle of an object's
+read sequence without affecting the result of reading it.
address@hidden itemize
+
address@hidden Input Streams
address@hidden Input Streams
address@hidden stream (for reading)
address@hidden input stream
+
+  Most of the Lisp functions for reading text take an @dfn{input stream}
+as an argument.  The input stream specifies where or how to get the
+characters of the text to be read.  Here are the possible types of input
+stream:
+
address@hidden @asis
address@hidden @var{buffer}
address@hidden buffer input stream
+The input characters are read from @var{buffer}, starting with the
+character directly after point.  Point advances as characters are read.
+
address@hidden @var{marker}
address@hidden marker input stream
+The input characters are read from the buffer that @var{marker} is in,
+starting with the character directly after the marker.  The marker
+position advances as characters are read.  The value of point in the
+buffer has no effect when the stream is a marker.
+
address@hidden @var{string}
address@hidden string input stream
+The input characters are taken from @var{string}, starting at the first
+character in the string and using as many characters as required.
+
address@hidden @var{function}
address@hidden function input stream
+The input characters are generated by @var{function}, which must support
+two kinds of calls:
+
address@hidden @bullet
address@hidden
+When it is called with no arguments, it should return the next character.
+
address@hidden
+When it is called with one argument (always a character), @var{function}
+should save the argument and arrange to return it on the next call.
+This is called @dfn{unreading} the character; it happens when the Lisp
+reader reads one character too many and wants to ``put it back where it
+came from.''  In this case, it makes no difference what value
address@hidden returns.
address@hidden itemize
+
address@hidden @code{t}
address@hidden @code{t} input stream
address@hidden used as a stream means that the input is read from the
+minibuffer.  In fact, the minibuffer is invoked once and the text
+given by the user is made into a string that is then used as the
+input stream.  If Emacs is running in batch mode, standard input is used
+instead of the minibuffer.  For example,
address@hidden
+(message "%s" (read t))
address@hidden example
+will read a Lisp expression from standard input and print the result
+to standard output.
+
address@hidden @code{nil}
address@hidden @code{nil} input stream
address@hidden supplied as an input stream means to use the value of
address@hidden instead; that value is the @dfn{default input
+stream}, and must be a address@hidden input stream.
+
address@hidden @var{symbol}
+A symbol as input stream is equivalent to the symbol's function
+definition (if any).
address@hidden table
+
+  Here is an example of reading from a stream that is a buffer, showing
+where point is located before and after:
+
address@hidden
address@hidden
+---------- Buffer: foo ----------
address@hidden is the contents of foo.
+---------- Buffer: foo ----------
address@hidden group
+
address@hidden
+(read (get-buffer "foo"))
+     @result{} is
address@hidden group
address@hidden
+(read (get-buffer "foo"))
+     @result{} the
address@hidden group
+
address@hidden
+---------- Buffer: foo ----------
+This is address@hidden contents of foo.
+---------- Buffer: foo ----------
address@hidden group
address@hidden example
+
address@hidden
+Note that the first read skips a space.  Reading skips any amount of
+whitespace preceding the significant text.
+
+  Here is an example of reading from a stream that is a marker,
+initially positioned at the beginning of the buffer shown.  The value
+read is the symbol @code{This}.
+
address@hidden
address@hidden
+
+---------- Buffer: foo ----------
+This is the contents of foo.
+---------- Buffer: foo ----------
address@hidden group
+
address@hidden
+(setq m (set-marker (make-marker) 1 (get-buffer "foo")))
+     @result{} #<marker at 1 in foo>
address@hidden group
address@hidden
+(read m)
+     @result{} This
address@hidden group
address@hidden
+m
+     @result{} #<marker at 5 in foo>   ;; @r{Before the first space.}
address@hidden group
address@hidden example
+
+  Here we read from the contents of a string:
+
address@hidden
address@hidden
+(read "(When in) the course")
+     @result{} (When in)
address@hidden group
address@hidden example
+
+  The following example reads from the minibuffer.  The
+prompt is: @address@hidden expression: }}.  (That is always the prompt
+used when you read from the stream @code{t}.)  The user's input is shown
+following the prompt.
+
address@hidden
address@hidden
+(read t)
+     @result{} 23
+---------- Buffer: Minibuffer ----------
+Lisp expression: @kbd{23 @key{RET}}
+---------- Buffer: Minibuffer ----------
address@hidden group
address@hidden example
+
+  Finally, here is an example of a stream that is a function, named
address@hidden  Before we use the stream, we initialize the
+variable @code{useless-list} to a list of characters.  Then each call to
+the function @code{useless-stream} obtains the next character in the list
+or unreads a character by adding it to the front of the list.
+
address@hidden
address@hidden
+(setq useless-list (append "XY()" nil))
+     @result{} (88 89 40 41)
address@hidden group
+
address@hidden
+(defun useless-stream (&optional unread)
+  (if unread
+      (setq useless-list (cons unread useless-list))
+    (prog1 (car useless-list)
+           (setq useless-list (cdr useless-list)))))
+     @result{} useless-stream
address@hidden group
address@hidden example
+
address@hidden
+Now we read using the stream thus constructed:
+
address@hidden
address@hidden
+(read 'useless-stream)
+     @result{} XY
address@hidden group
+
address@hidden
+useless-list
+     @result{} (40 41)
address@hidden group
address@hidden example
+
address@hidden
+Note that the open and close parentheses remain in the list.  The Lisp
+reader encountered the open parenthesis, decided that it ended the
+input, and unread it.  Another attempt to read from the stream at this
+point would read @samp{()} and return @code{nil}.
+
address@hidden get-file-char
+This function is used internally as an input stream to read from the
+input file opened by the function @code{load}.  Don't use this function
+yourself.
address@hidden defun
+
address@hidden Input Functions
address@hidden Input Functions
+
+  This section describes the Lisp functions and variables that pertain
+to reading.
+
+  In the functions below, @var{stream} stands for an input stream (see
+the previous section).  If @var{stream} is @code{nil} or omitted, it
+defaults to the value of @code{standard-input}.
+
address@hidden end-of-file
+  An @code{end-of-file} error is signaled if reading encounters an
+unterminated list, vector, or string.
+
address@hidden read &optional stream
+This function reads one textual Lisp expression from @var{stream},
+returning it as a Lisp object.  This is the basic Lisp input function.
address@hidden defun
+
address@hidden read-from-string string &optional start end
address@hidden string to object
+This function reads the first textual Lisp expression from the text in
address@hidden  It returns a cons cell whose @sc{car} is that expression,
+and whose @sc{cdr} is an integer giving the position of the next
+remaining character in the string (i.e., the first one not read).
+
+If @var{start} is supplied, then reading begins at index @var{start} in
+the string (where the first character is at index 0).  If you specify
address@hidden, then reading is forced to stop just before that index, as if
+the rest of the string were not there.
+
+For example:
+
address@hidden
address@hidden
+(read-from-string "(setq x 55) (setq y 5)")
+     @result{} ((setq x 55) . 11)
address@hidden group
address@hidden
+(read-from-string "\"A short string\"")
+     @result{} ("A short string" . 16)
address@hidden group
+
address@hidden
+;; @r{Read starting at the first character.}
+(read-from-string "(list 112)" 0)
+     @result{} ((list 112) . 10)
address@hidden group
address@hidden
+;; @r{Read starting at the second character.}
+(read-from-string "(list 112)" 1)
+     @result{} (list . 5)
address@hidden group
address@hidden
+;; @r{Read starting at the seventh character,}
+;;   @r{and stopping at the ninth.}
+(read-from-string "(list 112)" 6 8)
+     @result{} (11 . 8)
address@hidden group
address@hidden example
address@hidden defun
+
address@hidden standard-input
+This variable holds the default input stream---the stream that
address@hidden uses when the @var{stream} argument is @code{nil}.
+The default is @code{t}, meaning use the minibuffer.
address@hidden defvar
+
address@hidden Output Streams
address@hidden Output Streams
address@hidden stream (for printing)
address@hidden output stream
+
+  An output stream specifies what to do with the characters produced
+by printing.  Most print functions accept an output stream as an
+optional argument.  Here are the possible types of output stream:
+
address@hidden @asis
address@hidden @var{buffer}
address@hidden buffer output stream
+The output characters are inserted into @var{buffer} at point.
+Point advances as characters are inserted.
+
address@hidden @var{marker}
address@hidden marker output stream
+The output characters are inserted into the buffer that @var{marker}
+points into, at the marker position.  The marker position advances as
+characters are inserted.  The value of point in the buffer has no effect
+on printing when the stream is a marker, and this kind of printing
+does not move point (except that if the marker points at or before the
+position of point, point advances with the surrounding text, as
+usual).
+
address@hidden @var{function}
address@hidden function output stream
+The output characters are passed to @var{function}, which is responsible
+for storing them away.  It is called with a single character as
+argument, as many times as there are characters to be output, and
+is responsible for storing the characters wherever you want to put them.
+
address@hidden @code{t}
address@hidden @code{t} output stream
+The output characters are displayed in the echo area.
+
address@hidden @code{nil}
address@hidden @code{nil} output stream
address@hidden specified as an output stream means to use the value of
address@hidden instead; that value is the @dfn{default output
+stream}, and must not be @code{nil}.
+
address@hidden @var{symbol}
+A symbol as output stream is equivalent to the symbol's function
+definition (if any).
address@hidden table
+
+  Many of the valid output streams are also valid as input streams.  The
+difference between input and output streams is therefore more a matter
+of how you use a Lisp object, than of different types of object.
+
+  Here is an example of a buffer used as an output stream.  Point is
+initially located as shown immediately before the @samp{h} in
address@hidden  At the end, point is located directly before that same
address@hidden
+
address@hidden print example
address@hidden
address@hidden
+---------- Buffer: foo ----------
+This is address@hidden contents of foo.
+---------- Buffer: foo ----------
address@hidden group
+
+(print "This is the output" (get-buffer "foo"))
+     @result{} "This is the output"
+
address@hidden
+---------- Buffer: foo ----------
+This is t
+"This is the output"
address@hidden contents of foo.
+---------- Buffer: foo ----------
address@hidden group
address@hidden example
+
+  Now we show a use of a marker as an output stream.  Initially, the
+marker is in buffer @code{foo}, between the @samp{t} and the @samp{h} in
+the word @samp{the}.  At the end, the marker has advanced over the
+inserted text so that it remains positioned before the same @samp{h}.
+Note that the location of point, shown in the usual fashion, has no
+effect.
+
address@hidden
address@hidden
+---------- Buffer: foo ----------
+This is the @point{}output
+---------- Buffer: foo ----------
address@hidden group
+
address@hidden
+(setq m (copy-marker 10))
+     @result{} #<marker at 10 in foo>
address@hidden group
+
address@hidden
+(print "More output for foo." m)
+     @result{} "More output for foo."
address@hidden group
+
address@hidden
+---------- Buffer: foo ----------
+This is t
+"More output for foo."
+he @point{}output
+---------- Buffer: foo ----------
address@hidden group
+
address@hidden
+m
+     @result{} #<marker at 34 in foo>
address@hidden group
address@hidden example
+
+  The following example shows output to the echo area:
+
address@hidden
address@hidden
+(print "Echo Area output" t)
+     @result{} "Echo Area output"
+---------- Echo Area ----------
+"Echo Area output"
+---------- Echo Area ----------
address@hidden group
address@hidden example
+
+  Finally, we show the use of a function as an output stream.  The
+function @code{eat-output} takes each character that it is given and
+conses it onto the front of the list @code{last-output} (@pxref{Building
+Lists}).  At the end, the list contains all the characters output, but
+in reverse order.
+
address@hidden
address@hidden
+(setq last-output nil)
+     @result{} nil
address@hidden group
+
address@hidden
+(defun eat-output (c)
+  (setq last-output (cons c last-output)))
+     @result{} eat-output
address@hidden group
+
address@hidden
+(print "This is the output" 'eat-output)
+     @result{} "This is the output"
address@hidden group
+
address@hidden
+last-output
+     @result{} (10 34 116 117 112 116 117 111 32 101 104
+    116 32 115 105 32 115 105 104 84 34 10)
address@hidden group
address@hidden example
+
address@hidden
+Now we can put the output in the proper order by reversing the list:
+
address@hidden
address@hidden
+(concat (nreverse last-output))
+     @result{} "
+\"This is the output\"
+"
address@hidden group
address@hidden example
+
address@hidden
+Calling @code{concat} converts the list to a string so you can see its
+contents more clearly.
+
address@hidden Output Functions
address@hidden Output Functions
+
+  This section describes the Lisp functions for printing Lisp
+objects---converting objects into their printed representation.
+
address@hidden @samp{"} in printing
address@hidden @samp{\} in printing
address@hidden quoting characters in printing
address@hidden escape characters in printing
+  Some of the Emacs printing functions add quoting characters to the
+output when necessary so that it can be read properly.  The quoting
+characters used are @samp{"} and @samp{\}; they distinguish strings from
+symbols, and prevent punctuation characters in strings and symbols from
+being taken as delimiters when reading.  @xref{Printed Representation},
+for full details.  You specify quoting or no quoting by the choice of
+printing function.
+
+  If the text is to be read back into Lisp, then you should print with
+quoting characters to avoid ambiguity.  Likewise, if the purpose is to
+describe a Lisp object clearly for a Lisp programmer.  However, if the
+purpose of the output is to look nice for humans, then it is usually
+better to print without quoting.
+
+  Lisp objects can refer to themselves.  Printing a self-referential
+object in the normal way would require an infinite amount of text, and
+the attempt could cause infinite recursion.  Emacs detects such
+recursion and prints @address@hidden instead of recursively printing
+an object already being printed.  For example, here @samp{#0} indicates
+a recursive reference to the object at level 0 of the current print
+operation:
+
address@hidden
+(setq foo (list nil))
+     @result{} (nil)
+(setcar foo foo)
+     @result{} (#0)
address@hidden example
+
+  In the functions below, @var{stream} stands for an output stream.
+(See the previous section for a description of output streams.)  If
address@hidden is @code{nil} or omitted, it defaults to the value of
address@hidden
+
address@hidden print object &optional stream
address@hidden Lisp printer
+The @code{print} function is a convenient way of printing.  It outputs
+the printed representation of @var{object} to @var{stream}, printing in
+addition one newline before @var{object} and another after it.  Quoting
+characters are used.  @code{print} returns @var{object}.  For example:
+
address@hidden
address@hidden
+(progn (print 'The\ cat\ in)
+       (print "the hat")
+       (print " came back"))
+     @print{}
+     @print{} The\ cat\ in
+     @print{}
+     @print{} "the hat"
+     @print{}
+     @print{} " came back"
+     @result{} " came back"
address@hidden group
address@hidden example
address@hidden defun
+
address@hidden prin1 object &optional stream
+This function outputs the printed representation of @var{object} to
address@hidden  It does not print newlines to separate output as
address@hidden does, but it does use quoting characters just like
address@hidden  It returns @var{object}.
+
address@hidden
address@hidden
+(progn (prin1 'The\ cat\ in)
+       (prin1 "the hat")
+       (prin1 " came back"))
+     @print{} The\ cat\ in"the hat"" came back"
+     @result{} " came back"
address@hidden group
address@hidden example
address@hidden defun
+
address@hidden princ object &optional stream
+This function outputs the printed representation of @var{object} to
address@hidden  It returns @var{object}.
+
+This function is intended to produce output that is readable by people,
+not by @code{read}, so it doesn't insert quoting characters and doesn't
+put double-quotes around the contents of strings.  It does not add any
+spacing between calls.
+
address@hidden
address@hidden
+(progn
+  (princ 'The\ cat)
+  (princ " in the \"hat\""))
+     @print{} The cat in the "hat"
+     @result{} " in the \"hat\""
address@hidden group
address@hidden example
address@hidden defun
+
address@hidden terpri &optional stream
address@hidden newline in print
+This function outputs a newline to @var{stream}.  The name stands
+for ``terminate print.''
address@hidden defun
+
address@hidden write-char character &optional stream
+This function outputs @var{character} to @var{stream}.  It returns
address@hidden
address@hidden defun
+
address@hidden prin1-to-string object &optional noescape
address@hidden object to string
+This function returns a string containing the text that @code{prin1}
+would have printed for the same argument.
+
address@hidden
address@hidden
+(prin1-to-string 'foo)
+     @result{} "foo"
address@hidden group
address@hidden
+(prin1-to-string (mark-marker))
+     @result{} "#<marker at 2773 in strings.texi>"
address@hidden group
address@hidden example
+
+If @var{noescape} is address@hidden, that inhibits use of quoting
+characters in the output.  (This argument is supported in Emacs versions
+19 and later.)
+
address@hidden
address@hidden
+(prin1-to-string "foo")
+     @result{} "\"foo\""
address@hidden group
address@hidden
+(prin1-to-string "foo" t)
+     @result{} "foo"
address@hidden group
address@hidden example
+
+See @code{format}, in @ref{Formatting Strings}, for other ways to obtain
+the printed representation of a Lisp object as a string.
address@hidden defun
+
address@hidden with-output-to-string address@hidden
+This macro executes the @var{body} forms with @code{standard-output} set
+up to feed output into a string.  Then it returns that string.
+
+For example, if the current buffer name is @samp{foo},
+
address@hidden
+(with-output-to-string
+  (princ "The buffer is ")
+  (princ (buffer-name)))
address@hidden example
+
address@hidden
+returns @code{"The buffer is foo"}.
address@hidden defmac
+
address@hidden Output Variables
address@hidden Variables Affecting Output
address@hidden output-controlling variables
+
address@hidden standard-output
+The value of this variable is the default output stream---the stream
+that print functions use when the @var{stream} argument is @code{nil}.
+The default is @code{t}, meaning display in the echo area.
address@hidden defvar
+
address@hidden print-quoted
+If this is address@hidden, that means to print quoted forms using
+abbreviated reader syntax.  @code{(quote foo)} prints as @code{'foo},
address@hidden(function foo)} as @code{#'foo}, and backquoted forms print
+using modern backquote syntax.
address@hidden defvar
+
address@hidden print-escape-newlines
address@hidden @samp{\n} in print
address@hidden escape characters
+If this variable is address@hidden, then newline characters in strings
+are printed as @samp{\n} and formfeeds are printed as @samp{\f}.
+Normally these characters are printed as actual newlines and formfeeds.
+
+This variable affects the print functions @code{prin1} and @code{print}
+that print with quoting.  It does not affect @code{princ}.  Here is an
+example using @code{prin1}:
+
address@hidden
address@hidden
+(prin1 "a\nb")
+     @print{} "a
+     @print{} b"
+     @result{} "a
+b"
address@hidden group
+
address@hidden
+(let ((print-escape-newlines t))
+  (prin1 "a\nb"))
+     @print{} "a\nb"
+     @result{} "a
+b"
address@hidden group
address@hidden example
+
address@hidden
+In the second expression, the local binding of
address@hidden is in effect during the call to
address@hidden, but not during the printing of the result.
address@hidden defvar
+
address@hidden print-escape-nonascii
+If this variable is address@hidden, then unibyte address@hidden
+characters in strings are unconditionally printed as backslash sequences
+by the print functions @code{prin1} and @code{print} that print with
+quoting.
+
+Those functions also use backslash sequences for unibyte address@hidden
+characters, regardless of the value of this variable, when the output
+stream is a multibyte buffer or a marker pointing into one.
address@hidden defvar
+
address@hidden print-escape-multibyte
+If this variable is address@hidden, then multibyte address@hidden
+characters in strings are unconditionally printed as backslash sequences
+by the print functions @code{prin1} and @code{print} that print with
+quoting.
+
+Those functions also use backslash sequences for multibyte
address@hidden characters, regardless of the value of this variable,
+when the output stream is a unibyte buffer or a marker pointing into
+one.
address@hidden defvar
+
address@hidden print-length
address@hidden printing limits
+The value of this variable is the maximum number of elements to print in
+any list, vector or bool-vector.  If an object being printed has more
+than this many elements, it is abbreviated with an ellipsis.
+
+If the value is @code{nil} (the default), then there is no limit.
+
address@hidden
address@hidden
+(setq print-length 2)
+     @result{} 2
address@hidden group
address@hidden
+(print '(1 2 3 4 5))
+     @print{} (1 2 ...)
+     @result{} (1 2 ...)
address@hidden group
address@hidden example
address@hidden defvar
+
address@hidden print-level
+The value of this variable is the maximum depth of nesting of
+parentheses and brackets when printed.  Any list or vector at a depth
+exceeding this limit is abbreviated with an ellipsis.  A value of
address@hidden (which is the default) means no limit.
address@hidden defvar
+
address@hidden eval-expression-print-length
address@hidden eval-expression-print-level
+These are the values for @code{print-length} and @code{print-level}
+used by @code{eval-expression}, and thus, indirectly, by many
+interactive evaluation commands (@pxref{Lisp Eval,, Evaluating
+Emacs-Lisp Expressions, emacs, The GNU Emacs Manual}).
address@hidden defopt
+
+  These variables are used for detecting and reporting circular
+and shared structure:
+
address@hidden print-circle
+If address@hidden, this variable enables detection of circular
+and shared structure in printing.
address@hidden defvar
+
address@hidden print-gensym
+If address@hidden, this variable enables detection of uninterned symbols
+(@pxref{Creating Symbols}) in printing.  When this is enabled,
+uninterned symbols print with the prefix @samp{#:}, which tells the Lisp
+reader to produce an uninterned symbol.
address@hidden defvar
+
address@hidden print-continuous-numbering
+If address@hidden, that means number continuously across print calls.
+This affects the numbers printed for @address@hidden labels and
address@hidden@var{m}#} references.
+
+Don't set this variable with @code{setq}; you should only bind it
+temporarily to @code{t} with @code{let}.  When you do that, you should
+also bind @code{print-number-table} to @code{nil}.
address@hidden defvar
+
address@hidden print-number-table
+This variable holds a vector used internally by printing to implement
+the @code{print-circle} feature.  You should not use it except
+to bind it to @code{nil} when you bind @code{print-continuous-numbering}.
address@hidden defvar
+
address@hidden float-output-format
+This variable specifies how to print floating point numbers.  Its
+default value is @code{nil}, meaning use the shortest output
+that represents the number without losing information.
+
+To control output format more precisely, you can put a string in this
+variable.  The string should hold a @samp{%}-specification to be used
+in the C function @code{sprintf}.  For further restrictions on what
+you can use, see the variable's documentation string.
address@hidden defvar
+
address@hidden
+   arch-tag: 07636b8c-c4e3-4735-9e06-2e864320b434
address@hidden ignore