171 |
@kindex UP |
@kindex UP |
172 |
@kindex DOWN |
@kindex DOWN |
173 |
@findex beginning-of-line |
@findex beginning-of-line |
174 |
@findex end-of-line |
@findex move-end-of-line |
175 |
@findex forward-char |
@findex forward-char |
176 |
@findex backward-char |
@findex backward-char |
177 |
@findex next-line |
@findex next-line |
185 |
@item C-a |
@item C-a |
186 |
Move to the beginning of the line (@code{beginning-of-line}). |
Move to the beginning of the line (@code{beginning-of-line}). |
187 |
@item C-e |
@item C-e |
188 |
Move to the end of the line (@code{end-of-line}). |
Move to the end of the line (@code{move-end-of-line}). |
189 |
@item C-f |
@item C-f |
190 |
Move forward one character (@code{forward-char}). The right-arrow key |
Move forward one character (@code{forward-char}). The right-arrow key |
191 |
does the same thing. |
does the same thing. |
380 |
|
|
381 |
@vindex undo-limit |
@vindex undo-limit |
382 |
@vindex undo-strong-limit |
@vindex undo-strong-limit |
383 |
|
@vindex undo-outer-limit |
384 |
@cindex undo limit |
@cindex undo limit |
385 |
When the undo information for a buffer becomes too large, Emacs |
When the undo information for a buffer becomes too large, Emacs |
386 |
discards the oldest undo information from time to time (during garbage |
discards the oldest undo information from time to time (during garbage |
387 |
collection). You can specify how much undo information to keep by |
collection). You can specify how much undo information to keep by |
388 |
setting two variables: @code{undo-limit} and @code{undo-strong-limit}. |
setting three variables: @code{undo-limit}, @code{undo-strong-limit}, |
389 |
Their values are expressed in units of bytes of space. |
and @code{undo-outer-limit}. Their values are expressed in units of |
390 |
|
bytes of space. |
391 |
|
|
392 |
The variable @code{undo-limit} sets a soft limit: Emacs keeps undo |
The variable @code{undo-limit} sets a soft limit: Emacs keeps undo |
393 |
data for enough commands to reach this size, and perhaps exceed it, but |
data for enough commands to reach this size, and perhaps exceed it, |
394 |
does not keep data for any earlier commands beyond that. Its default |
but does not keep data for any earlier commands beyond that. Its |
395 |
value is 20000. The variable @code{undo-strong-limit} sets a stricter |
default value is 20000. The variable @code{undo-strong-limit} sets a |
396 |
limit: the command which pushes the size past this amount is itself |
stricter limit: a previous command (not the most recent one) which |
397 |
forgotten. Its default value is 30000. |
pushes the size past this amount is itself forgotten. The default |
398 |
|
value of @code{undo-strong-limit} is 30000. |
399 |
Regardless of the values of those variables, the most recent change is |
|
400 |
never discarded, so there is no danger that garbage collection occurring |
Regardless of the values of those variables, the most recent change |
401 |
right after an unintentional large change might prevent you from undoing |
is never discarded unless it gets bigger than @code{undo-outer-limit} |
402 |
it. |
(normally 300,000). At that point, Emacs asks whether to discard the |
403 |
|
undo information even for the current command. (You also have the |
404 |
|
option of quitting.) So there is normally no danger that garbage |
405 |
|
collection occurring right after an unintentional large change might |
406 |
|
prevent you from undoing it. But if you didn't expect the command |
407 |
|
to create such large undo data, you can get rid of it and prevent |
408 |
|
Emacs from running out of memory. |
409 |
|
|
410 |
The reason the @code{undo} command has two keys, @kbd{C-x u} and |
The reason the @code{undo} command has two keys, @kbd{C-x u} and |
411 |
@kbd{C-_}, set up to run it is that it is worthy of a single-character |
@kbd{C-_}, set up to run it is that it is worthy of a single-character |