diff options
| -rw-r--r-- | doc/lispintro/ChangeLog | 4 | ||||
| -rw-r--r-- | doc/lispintro/emacs-lisp-intro.texi | 44 | ||||
| -rw-r--r-- | doc/lispref/ChangeLog | 5 | ||||
| -rw-r--r-- | doc/lispref/positions.texi | 21 | ||||
| -rw-r--r-- | etc/NEWS | 2 | ||||
| -rw-r--r-- | src/ChangeLog | 6 | ||||
| -rw-r--r-- | src/editfns.c | 54 |
7 files changed, 55 insertions, 81 deletions
diff --git a/doc/lispintro/ChangeLog b/doc/lispintro/ChangeLog index 57ab03b1155..c54c165d22c 100644 --- a/doc/lispintro/ChangeLog +++ b/doc/lispintro/ChangeLog @@ -1,3 +1,7 @@ +2015-03-25 Stefan Monnier <monnier@iro.umontreal.ca> + + * emacs-lisp-intro.texi: `save-excursion' doesn't save&restore the mark. + 2014-12-31 Paul Eggert <eggert@cs.ucla.edu> Less 'make' chatter for Emacs doc diff --git a/doc/lispintro/emacs-lisp-intro.texi b/doc/lispintro/emacs-lisp-intro.texi index c67623d89cb..ed125bb3747 100644 --- a/doc/lispintro/emacs-lisp-intro.texi +++ b/doc/lispintro/emacs-lisp-intro.texi @@ -352,7 +352,7 @@ How To Write Function Definitions * if:: What if? * else:: If--then--else expressions. * Truth & Falsehood:: What Lisp considers false and true. -* save-excursion:: Keeping track of point, mark, and buffer. +* save-excursion:: Keeping track of point and buffer. * Review:: * defun Exercises:: @@ -2966,7 +2966,7 @@ symbol refers to it.) * if:: What if? * else:: If--then--else expressions. * Truth & Falsehood:: What Lisp considers false and true. -* save-excursion:: Keeping track of point, mark, and buffer. +* save-excursion:: Keeping track of point and buffer. * Review:: * defun Exercises:: @end menu @@ -4159,11 +4159,11 @@ The @code{save-excursion} function is the third and final special form that we will discuss in this chapter. In Emacs Lisp programs used for editing, the @code{save-excursion} -function is very common. It saves the location of point and mark, -executes the body of the function, and then restores point and mark to -their previous positions if their locations were changed. Its primary +function is very common. It saves the location of point, +executes the body of the function, and then restores point to +its previous position if its location was changed. Its primary purpose is to keep the user from being surprised and disturbed by -unexpected movement of point or mark. +unexpected movement of point. @menu * Point and mark:: A review of various locations. @@ -4201,7 +4201,7 @@ region}. Numerous commands work on the region, including @code{print-region}. The @code{save-excursion} special form saves the locations of point and -mark and restores those positions after the code within the body of the +restores this position after the code within the body of the special form is evaluated by the Lisp interpreter. Thus, if point were in the beginning of a piece of text and some code moved point to the end of the buffer, the @code{save-excursion} would put point back to where @@ -4212,16 +4212,16 @@ In Emacs, a function frequently moves point as part of its internal workings even though a user would not expect this. For example, @code{count-lines-region} moves point. To prevent the user from being bothered by jumps that are both unexpected and (from the user's point of -view) unnecessary, @code{save-excursion} is often used to keep point and -mark in the location expected by the user. The use of +view) unnecessary, @code{save-excursion} is often used to keep point in +the location expected by the user. The use of @code{save-excursion} is good housekeeping. To make sure the house stays clean, @code{save-excursion} restores the -values of point and mark even if something goes wrong in the code inside +value of point even if something goes wrong in the code inside of it (or, to be more precise and to use the proper jargon, ``in case of abnormal exit''). This feature is very helpful. -In addition to recording the values of point and mark, +In addition to recording the value of point, @code{save-excursion} keeps track of the current buffer, and restores it, too. This means you can write code that will change the buffer and have @code{save-excursion} switch you back to the original buffer. @@ -4386,9 +4386,9 @@ For example, @end smallexample @item save-excursion -Record the values of point and mark and the current buffer before -evaluating the body of this special form. Restore the values of point -and mark and buffer afterward. +Record the values of point and the current buffer before +evaluating the body of this special form. Restore the value of point and +buffer afterward. @need 1250 For example, @@ -5201,8 +5201,8 @@ of the two-element list, @code{(oldbuf (current-buffer))}. The body of the @code{let} expression in @code{append-to-buffer} consists of a @code{save-excursion} expression. -The @code{save-excursion} function saves the locations of point and -mark, and restores them to those positions after the expressions in the +The @code{save-excursion} function saves the location of point, and restores it +to that position after the expressions in the body of the @code{save-excursion} complete execution. In addition, @code{save-excursion} keeps track of the original buffer, and restores it. This is how @code{save-excursion} is used in @@ -5390,7 +5390,7 @@ Conventionally bound to @kbd{M-.} (that's a period following the @key{META} key). @item save-excursion -Save the location of point and mark and restore their values after the +Save the location of point and restore its value after the arguments to @code{save-excursion} have been evaluated. Also, remember the current buffer and return to it. @@ -5896,7 +5896,7 @@ the value of point, which will be at the end of the inserted text, is recorded in the variable @code{newmark}. After the body of the outer @code{save-excursion} is evaluated, point -and mark are relocated to their original places. +is relocated to its original place. However, it is convenient to locate a mark at the end of the newly inserted text and locate point at its beginning. The @code{newmark} @@ -6685,8 +6685,8 @@ restored just before the completion of the function by the @code{save-restriction} special form. The call to @code{widen} is followed by @code{save-excursion}, which -saves the location of the cursor (i.e., of point) and of the mark, and -restores them after the code in the body of the @code{save-excursion} +saves the location of the cursor (i.e., of point), and +restores it after the code in the body of the @code{save-excursion} uses the @code{beginning-of-line} function to move point. (Note that the @code{(widen)} expression comes between the @@ -6757,8 +6757,8 @@ it, and @code{count-lines} counts only the lines @emph{before} the current line. After @code{count-lines} has done its job, and the message has been -printed in the echo area, the @code{save-excursion} restores point and -mark to their original positions; and @code{save-restriction} restores +printed in the echo area, the @code{save-excursion} restores point to +its original position; and @code{save-restriction} restores the original narrowing, if any. @node narrow Exercise diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog index 9b1bbb357a5..9e1b7b074e2 100644 --- a/doc/lispref/ChangeLog +++ b/doc/lispref/ChangeLog @@ -1,3 +1,8 @@ +2015-03-25 Stefan Monnier <monnier@iro.umontreal.ca> + + * positions.texi (Excursions, Narrowing): `save-excursion' does not + save&restore the mark any more. + 2015-03-24 Paul Eggert <eggert@cs.ucla.edu> * numbers.texi (Float Basics): Improve ldexp documentation. diff --git a/doc/lispref/positions.texi b/doc/lispref/positions.texi index b74116ebf1d..103161c7ae2 100644 --- a/doc/lispref/positions.texi +++ b/doc/lispref/positions.texi @@ -825,8 +825,8 @@ is zero or less. It is often useful to move point ``temporarily'' within a localized portion of the program. This is called an @dfn{excursion}, and it is done with the @code{save-excursion} special form. This construct -remembers the initial identity of the current buffer, and its values -of point and the mark, and restores them after the excursion +remembers the initial identity of the current buffer, and its value +of point, and restores them after the excursion completes. It is the standard way to move point within one part of a program and avoid affecting the rest of the program, and is used thousands of times in the Lisp sources of Emacs. @@ -841,18 +841,18 @@ Configurations} and in @ref{Frame Configurations}. @c frameset? @cindex mark excursion @cindex point excursion This special form saves the identity of the current buffer and the -values of point and the mark in it, evaluates @var{body}, and finally -restores the buffer and its saved values of point and the mark. All -three saved values are restored even in case of an abnormal exit via +value of point in it, evaluates @var{body}, and finally +restores the buffer and its saved value of point. both saved values are +restored even in case of an abnormal exit via @code{throw} or error (@pxref{Nonlocal Exits}). The value returned by @code{save-excursion} is the result of the last form in @var{body}, or @code{nil} if no body forms were given. @end defspec - Because @code{save-excursion} only saves point and mark for the + Because @code{save-excursion} only saves point for the buffer that was current at the start of the excursion, any changes -made to point and/or mark in other buffers, during the excursion, will +made to point in other buffers, during the excursion, will remain in effect afterward. This frequently leads to unintended consequences, so the byte compiler warns if you call @code{set-buffer} during an excursion: @@ -888,11 +888,6 @@ type @code{nil}. @xref{Marker Insertion Types}. Therefore, when the saved point value is restored, it normally comes before the inserted text. - Although @code{save-excursion} saves the location of the mark, it does -not prevent functions which modify the buffer from setting -@code{deactivate-mark}, and thus causing the deactivation of the mark -after the command finishes. @xref{The Mark}. - @node Narrowing @section Narrowing @cindex narrowing @@ -980,7 +975,7 @@ restores the restrictions on the original buffer (the buffer whose restrictions it saved from), but it does not restore the identity of the current buffer. -@code{save-restriction} does @emph{not} restore point and the mark; use +@code{save-restriction} does @emph{not} restore point; use @code{save-excursion} for that. If you use both @code{save-restriction} and @code{save-excursion} together, @code{save-excursion} should come first (on the outside). Otherwise, the old point value would be @@ -617,6 +617,8 @@ a typographically-correct documents. * Incompatible Lisp Changes in Emacs 25.1 +** `save-excursion' does not save&restore the mark any more. + ** read-buffer-function can now be called with a 4th argument (`predicate'). ** completion-table-dynamic stays in the minibuffer. diff --git a/src/ChangeLog b/src/ChangeLog index 23f125c567d..632b798ce08 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,9 @@ +2015-03-25 Stefan Monnier <monnier@iro.umontreal.ca> + + * editfns.c (save_excursion_save): Don't save the mark. + (save_excursion_restore): Don't restore the mark. + (Fsave_excursion): Fix docstring accordingly. + 2015-03-24 Paul Eggert <eggert@cs.ucla.edu> Fix minor ldexp issues diff --git a/src/editfns.c b/src/editfns.c index 7c146f13e14..f463890a98d 100644 --- a/src/editfns.c +++ b/src/editfns.c @@ -849,14 +849,11 @@ save_excursion_save (void) { return make_save_obj_obj_obj_obj (Fpoint_marker (), - /* Do not copy the mark if it points to nowhere. */ - (XMARKER (BVAR (current_buffer, mark))->buffer - ? Fcopy_marker (BVAR (current_buffer, mark), Qnil) - : Qnil), + Qnil, /* Selected window if current buffer is shown in it, nil otherwise. */ (EQ (XWINDOW (selected_window)->contents, Fcurrent_buffer ()) ? selected_window : Qnil), - BVAR (current_buffer, mark_active)); + Qnil); } /* Restore saved buffer before leaving `save-excursion' special form. */ @@ -864,8 +861,8 @@ save_excursion_save (void) void save_excursion_restore (Lisp_Object info) { - Lisp_Object tem, tem1, omark, nmark; - struct gcpro gcpro1, gcpro2, gcpro3; + Lisp_Object tem, tem1; + struct gcpro gcpro1; tem = Fmarker_buffer (XSAVE_OBJECT (info, 0)); /* If we're unwinding to top level, saved buffer may be deleted. This @@ -873,8 +870,7 @@ save_excursion_restore (Lisp_Object info) if (NILP (tem)) goto out; - omark = nmark = Qnil; - GCPRO3 (info, omark, nmark); + GCPRO1 (info); Fset_buffer (tem); @@ -883,34 +879,6 @@ save_excursion_restore (Lisp_Object info) Fgoto_char (tem); unchain_marker (XMARKER (tem)); - /* Mark marker. */ - tem = XSAVE_OBJECT (info, 1); - omark = Fmarker_position (BVAR (current_buffer, mark)); - if (NILP (tem)) - unchain_marker (XMARKER (BVAR (current_buffer, mark))); - else - { - Fset_marker (BVAR (current_buffer, mark), tem, Fcurrent_buffer ()); - nmark = Fmarker_position (tem); - unchain_marker (XMARKER (tem)); - } - - /* Mark active. */ - tem = XSAVE_OBJECT (info, 3); - tem1 = BVAR (current_buffer, mark_active); - bset_mark_active (current_buffer, tem); - - /* If mark is active now, and either was not active - or was at a different place, run the activate hook. */ - if (! NILP (tem)) - { - if (! EQ (omark, nmark)) - run_hook (intern ("activate-mark-hook")); - } - /* If mark has ceased to be active, run deactivate hook. */ - else if (! NILP (tem1)) - run_hook (intern ("deactivate-mark-hook")); - /* If buffer was visible in a window, and a different window was selected, and the old selected window is still showing this buffer, restore point in that window. */ @@ -932,18 +900,12 @@ save_excursion_restore (Lisp_Object info) } DEFUN ("save-excursion", Fsave_excursion, Ssave_excursion, 0, UNEVALLED, 0, - doc: /* Save point, mark, and current buffer; execute BODY; restore those things. + doc: /* Save point, and current buffer; execute BODY; restore those things. Executes BODY just like `progn'. -The values of point, mark and the current buffer are restored +The values of point and the current buffer are restored even in case of abnormal exit (throw or error). -The state of activation of the mark is also restored. - -This construct does not save `deactivate-mark', and therefore -functions that change the buffer will still cause deactivation -of the mark at the end of the command. To prevent that, bind -`deactivate-mark' with `let'. -If you only want to save the current buffer but not point nor mark, +If you only want to save the current buffer but not point, then just use `save-current-buffer', or even `with-current-buffer'. usage: (save-excursion &rest BODY) */) |