direction. By default, @code{scroll-conservatively} is@tie{}0, which
means to always center point in the window.
This said, in minibuffer windows, scrolling is always conservative by
-default because @code{scroll-minibuffer-conservatively} is non-nil,
+default because @code{scroll-minibuffer-conservatively} is non-@code{nil},
which takes precedence over @code{scroll-conservatively}.
@vindex scroll-step
@cindex crashes, Haiku
@cindex haiku debugger
@vindex haiku-debug-on-fatal-error
- If the variable @code{haiku-debug-on-fatal-error} is non-nil, Emacs
+ If the variable @code{haiku-debug-on-fatal-error} is non-@code{nil}, Emacs
will launch the system debugger when a fatal signal is received. It
defaults to @code{t}. If GDB cannot be used on your system, please
attach the report generated by the system debugger when reporting a
@vindex ns-auto-hide-menu-bar
@item ns-auto-hide-menu-bar
This variable specifies whether the macOS menu bar is hidden when an
-Emacs frame is selected. If non-nil the menu bar is not shown unless
+Emacs frame is selected. If non-@code{nil} the menu bar is not shown unless
the mouse pointer is moved near to the top of the screen.
@vindex ns-use-native-fullscreen
@item ns-use-mwheel-acceleration
This variable controls whether Emacs ignores the system mousewheel
acceleration. When nil each `click' of the mousewheel will correspond
-exactly with one mousewheel event. When non-nil, the default, each
+exactly with one mousewheel event. When non-@code{nil}, the default, each
`click' may correspond with more than one mousewheel event, depending
on the user's input.
@vindex ns-use-mwheel-momentum
@item ns-use-mwheel-momentum
This variable controls whether Emacs ignores the system `momentum'
-when scrolling using a trackpad. When non-nil, the default, scrolling
+when scrolling using a trackpad. When non-@code{nil}, the default, scrolling
rapidly may result in the buffer continuing to scroll for a short
while after the user has lifted their fingers off the trackpad.
and @code{bug-reference-maybe-setup-from-irc} which does the setup
according to @code{bug-reference-setup-from-irc-alist}.
@end itemize
-A setup function should return non-nil if it could setup bug-reference
+A setup function should return non-@code{nil} if it could setup bug-reference
mode which is the case if the last thing the function does is calling
one of the helper functions above.
@code{comint-terminfo-terminal} to let you choose a terminal with more
advanced features, as defined in your system's terminfo database.
Emacs will use this option as the value for @env{TERM} so long as
-@code{system-uses-terminfo} is non-nil.
+@code{system-uses-terminfo} is non-@code{nil}.
Both @code{comint-terminfo-terminal} and @code{system-uses-terminfo}
can be declared as connection-local variables to adjust these options
@var{replacement} [@var{uniquify}])}}. @var{regexp} is a regular
expression to match against the file name; if it matches,
@code{replace-match} is used to replace the matching part with
-@var{replacement}. If the optional element @var{uniquify} is non-nil,
+@var{replacement}. If the optional element @var{uniquify} is non-@code{nil},
the auto-save file name is constructed by concatenating the directory
part of the transformed file name with the buffer's file name in which
all directory separators were changed to @samp{!} to prevent clashes.
@var{frame-or-window}, which defaults to the selected window.
The coordinates @var{x} and @var{y} are relative to the
text area of the selected window.
-If @var{whole} is @code{non-nil}, the @var{x} coordinate is relative
+If @var{whole} is non-@code{nil}, the @var{x} coordinate is relative
to the entire window area including scroll bars, margins and fringes.
@end defun
@end defopt
@defopt native-comp-async-query-on-exit
-If this variable's value is non-nil, Emacs will query upon exiting
+If this variable's value is non-@code{nil}, Emacs will query upon exiting
whether to exit and kill any asynchronous native-compilation
subprocesses that are still running, thus preventing the corresponding
@file{.eln} files from being written. If the value is @code{nil}, the
@code{:color} means to use the foreground color of the face.
@var{style} should be a symbol @code{line} or @code{wave}, meaning to
use a straight or wavy line. Omitting the attribute @code{:style}
-means to use a straight line. @var{position}, if non-nil, means to
+means to use a straight line. @var{position}, if non-@code{nil}, means to
display the underline at the descent of the text, instead of at the
baseline level. If it is a number, then it specifies the amount of
pixels above the descent to display the underline.
signal an error if a search query has not been already started in
@var{xwidget} through @code{xwidget-webkit-search}.
-If @code{wrap-around} was non-nil when @code{xwidget-webkit-search}
+If @code{wrap-around} was non-@code{nil} when @code{xwidget-webkit-search}
was called, then the search will restart from the beginning of the
document when its end is reached.
@end defun
signals an error if a search query has not been already started in
@var{xwidget} through @code{xwidget-webkit-search}.
-If @code{wrap-around} was non-nil when @code{xwidget-webkit-search}
+If @code{wrap-around} was non-@code{nil} when @code{xwidget-webkit-search}
was called, then the search will restart from the end of the
document when its beginning is reached.
@end defun
@var{pattern} is, by default, a ``glob''/wildcard string, e.g.,
@samp{"/tmp/*.png"} or @samp{"/*/*/foo.png"}, but can also be a
-regular expression if the optional @var{regexp} parameter is non-nil.
+regular expression if the optional @var{regexp} parameter is non-@code{nil}.
In any case, the matches are applied per sub-directory, so a match
can't span a parent/sub directory.
function should be inserted in the list: it should then be a number
between -100 and 100 where the higher the value, the closer to the end of the
list the function should go. The @var{depth} defaults to 0 and for backward
-compatibility when @var{depth} is a non-nil symbol it is interpreted as a depth
+compatibility when @var{depth} is a non-@code{nil} symbol it is interpreted as a depth
of 90. Furthermore, when @var{depth} is strictly greater than 0 the function
is added @emph{after} rather than before functions of the same depth.
One should never use a depth of 100 (or -100), because one can never be
@vindex tabulated-list-use-header-line
@defun tabulated-list-header-overlay-p &optional POS
-This @code{defsubst} returns non-nil if there is a fake header at
+This @code{defsubst} returns non-@code{nil} if there is a fake header at
@var{pos}. A fake header is used if
@code{tabulated-list-use-header-line} is @code{nil} to put the column
names at the beginning of the buffer. If omitted or @code{nil},
The padding area can be empty space at the beginning of the line, the
width of which is governed by @code{tabulated-list-padding}.
@var{tag} should be a string, with a length less than or equal to
-@code{tabulated-list-padding}. If @var{advance} is non-nil, this
+@code{tabulated-list-padding}. If @var{advance} is non-@code{nil}, this
function advances point by one line.
@end defun
the name of the column to change. @var{desc} is the new column
descriptor, which is inserted via @code{tabulated-list-print-col}.
-If @var{change-entry-data} is non-nil, this function modifies the
+If @var{change-entry-data} is non-@code{nil}, this function modifies the
underlying data (usually the column descriptor in the list
@code{tabulated-list-entries}) by setting the column descriptor of the
vector to @code{desc}.
Since there are processes violating this rule, returning exit codes
greater than 128 which are not bound to a signal, @code{process-file}
returns always the exit code as natural number for remote processes.
-Setting this user option to non-nil forces @code{process-file} to
+Setting this user option to non-@code{nil} forces @code{process-file} to
interpret such exit codes as signals, and to return a corresponding
string.
@end defopt
@item @code{lower}, @code{lower-case}
Match anything lower-case, as determined by the current case table.
-If @code{case-fold-search} is non-nil, this also matches any
+If @code{case-fold-search} is non-@code{nil}, this also matches any
upper-case letter.
@item @code{upper}, @code{upper-case}
Match anything upper-case, as determined by the current case table.
-If @code{case-fold-search} is non-nil, this also matches any
+If @code{case-fold-search} is non-@code{nil}, this also matches any
lower-case letter.
@item @code{graph}, @code{graphic}
@end defvar
@defvar print-symbols-bare
-When bound to non-nil, the Lisp printer prints only the bare symbol of
+When bound to non-@code{nil}, the Lisp printer prints only the bare symbol of
a symbol with position, ignoring the position.
@end defvar
it interferes with selective undo of that command. To make @code{undo}
ignore the active region when invoked immediately after such a command,
set the property @code{undo-inhibit-region} of the command's function
-symbol to a non-nil value. @xref{Standard Properties}.
+symbol to a non-@code{nil} value. @xref{Standard Properties}.
@node Maintaining Undo
@section Maintaining Undo Lists
any system resources (e.g.@: processes, timers, etc.) used to listen for
messages on the wire should be released in @code{jsonrpc-shutdown},
i.e.@: they should only be needed while @code{jsonrpc-running-p} is
-non-nil.
+non-@code{nil}.
@end enumerate
The value of this option is an alist mapping conditions to display
actions. Each condition is passed to @code{buffer-match-p}, along
with the buffer name and the @var{action} argument passed to
-@code{display-buffer}. If it returns a non-nil value, then
+@code{display-buffer}. If it returns a non-@code{nil} value, then
@code{display-buffer} uses the corresponding display action to display
the buffer.
@end defopt
@defvar c-asymmetry-fontification-flag
@vindex asymmetry-fontification-flag @r{(c-)}
-When @code{c-asymmetry-fontification-flag} is non-nil (which it is by
+When @code{c-asymmetry-fontification-flag} is non-@code{nil} (which it is by
default), code like the above, with white space either before or after
the operator, but not both, is fontified as a declaration. When the
variable is nil, such a construct gets the default face.
@table @code
@item :read-only
-A non-nil value means the slot should not be @code{setf}-able;
+A non-@code{nil} value means the slot should not be @code{setf}-able;
the slot's value is determined when the object is created and does
not change afterward.
@table @var
@item short
-This element, if non-nil, should be a character to be used as a short
+This element, if non-@code{nil}, should be a character to be used as a short
switch, like @code{-@var{short}}. At least one of this element and
-@var{long} must be non-nil.
+@var{long} must be non-@code{nil}.
@item long
-This element, if non-nil, should be a string to be used as a long
+This element, if non-@code{nil}, should be a string to be used as a long
switch, like @code{--@var{long}}.
@item value
Which fringe (if any) should show the warning/error bitmaps.
@item flymake-wrap-around
-If non-nil, moving to errors with @code{flymake-goto-next-error} and
+If non-@code{nil}, moving to errors with @code{flymake-goto-next-error} and
@code{flymake-goto-prev-error} wraps around buffer boundaries.
@end vtable
@item flymake-proc-diagnostic-type-pred
A function to classify a diagnostic text as particular type of error.
Should be a function taking an error text and returning a diagnostic
-symbol (@pxref{Flymake error types}). If non-nil is returned but
+symbol (@pxref{Flymake error types}). If non-@code{nil} is returned but
there is no such symbol in that table, a warning is assumed. If nil
is returned, an error is assumed. Can also be a regular expression
that should match only warnings. This variable replaces the old
course, it'll make group entry somewhat slow.
@vindex gnus-refer-thread-use-search
-If @code{gnus-refer-thread-use-search} is non-nil then those backends
+If @code{gnus-refer-thread-use-search} is non-@code{nil} then those backends
that know how to find threads directly will search not just in the
current group but all groups on the same server.
non-virtual group this may not be possible. In this case a new
summary buffer is created holding a virtual group with the result of
the thread search.) If @code{gnus-refer-thread-limit-to-thread} is
-non-nil then the summary buffer will be limited to articles in the
+non-@code{nil} then the summary buffer will be limited to articles in the
thread.
@item M-^ (Summary)
Search queries can be specified one of two ways: either using the
syntax of the engine responsible for the group you're searching, or
using Gnus' generalized search syntax. Set the option
-@code{gnus-search-use-parsed-queries} to a non-nil value to used the
+@code{gnus-search-use-parsed-queries} to a non-@code{nil} value to used the
generalized syntax. The advantage of this syntax is that, if you have
multiple backends indexed by different engines, you don't need to
remember which one you're searching---it's also possible to issue the
@end defvar
@defvar gnus-registry-register-all
-If this option is non-nil, the registry will register all messages, as
+If this option is non-@code{nil}, the registry will register all messages, as
you see them. This is important to making split-to-parent and
Message-ID references work correctly, as the registry needs to know
where all messages are, but it can slow down group opening and the
in your fancy split setup.
-If @code{gnus-registry-register-all} is non-nil (the default), the
+If @code{gnus-registry-register-all} is non-@code{nil} (the default), the
registry will perform splitting for all messages. If it is nil,
splitting will only happen for children of messages you've explicitly
registered.
@defun gnus-registry-get-id-key (id key)
Get the data under @code{key} for message @code{id}. If the option
-@code{gnus-registry-register-all} is non-nil, this function will also
+@code{gnus-registry-register-all} is non-@code{nil}, this function will also
create an entry for @code{id} if one doesn't exist.
@end defun
support (check the value of @code{(featurep 'dbusbind)}), Gnus can
register a D-Bus signal to automatically close all server connections
before the system goes to sleep. To enable this, set
-@code{gnus-dbus-close-on-sleep} to a non-nil value.
+@code{gnus-dbus-close-on-sleep} to a non-@code{nil} value.
For more information about D-Bus and Emacs, @pxref{Top,,, dbus, D-Bus integration in Emacs}.
@vindex newsticker-obsolete-item-max-age
@item newsticker-keep-obsolete-items
Obsolete headlines are removed immediately unless
-@code{newsticker-keep-obsolete-items} is non-nil in which case they
+@code{newsticker-keep-obsolete-items} is non-@code{nil} in which case they
are kept until @code{newsticker-obsolete-item-max-age} is reached.
@vindex newsticker-automatically-mark-items-as-old
@vindex rcirc-track-ignore-server-buffer-flag
If the user wishes to ignore events in the server buffer, set
-@code{rcirc-track-ignore-server-buffer-flag} to a non-nil value.
+@code{rcirc-track-ignore-server-buffer-flag} to a non-@code{nil} value.
@node Reference
@chapter Reference
@cindex rcirc-track-abbrevate-flag
By default the channel names are abbreviated, set
-@code{rcirc-track-abbrevate-flag} to a non-nil value. This might be
+@code{rcirc-track-abbrevate-flag} to a non-@code{nil} value. This might be
interesting if the IRC activities are not tracked in the mode line,
but somewhere else.
they are never active at the same time, see @ref{Predicate Slots}.
Unfortunately both false-positives and false-negatives are possible.
-To deal with the former use non-nil @var{KEEP-OTHER@.} To deal with the
+To deal with the former use non-@code{nil} @var{KEEP-OTHER@.} To deal with the
latter remove the conflicting binding explicitly.
@end defun
@dfn{unreserved characters} by RFC 3986 (see the variable
@code{url-unreserved-chars}). Otherwise, @var{allowed-chars} should
be either a list of allowed chars, or a vector whose Nth element is
-non-nil if character N is allowed.
+non-@code{nil} if character N is allowed.
@end defun
@defun url-unhex-string string &optional allow-newlines
projects / emacs.git / commitdiff