diff options
Diffstat (limited to 'runtime/doc/undo.txt')
| -rw-r--r-- | runtime/doc/undo.txt | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/runtime/doc/undo.txt b/runtime/doc/undo.txt index 98ab60c7e7..3fcc196250 100644 --- a/runtime/doc/undo.txt +++ b/runtime/doc/undo.txt @@ -114,7 +114,17 @@ use CTRL-G u. This is useful if you want an insert command to be undoable in parts. E.g., for each sentence. |i_CTRL-G_u| Setting the value of 'undolevels' also closes the undo block. Even when the -new value is equal to the old value: > +new value is equal to the old value. Use `g:undolevels` to explicitly read +and write only the global value of 'undolevels'. > + let &g:undolevels = &g:undolevels + +Note that the similar-looking assignment `let &undolevels=&undolevels` does not +preserve the global option value of 'undolevels' in the event that the local +option has been set to a different value. For example: > + " Start with different global and local values for 'undolevels'. + let &g:undolevels = 1000 + let &l:undolevels = 2000 + " This assignment changes the global option to 2000: let &undolevels = &undolevels ============================================================================== @@ -255,7 +265,7 @@ ignored if its owner differs from the owner of the edited file, except when the owner of the undo file is the current user. Set 'verbose' to get a message about that when opening a file. -Location of the undo files is controlled by the 'undodir' option, by default +Location of the undo files is controlled by the 'undodir' option, by default they are saved to the dedicated directory in the application data folder. You can also save and restore undo histories by using ":wundo" and ":rundo" @@ -351,12 +361,20 @@ undo is possible. Use this if you are running out of memory. When you set 'undolevels' to -1 the undo information is not immediately cleared, this happens at the next change. To force clearing the undo information you can use these commands: > - :let old_undolevels = &undolevels - :set undolevels=-1 + :let old_undolevels = &l:undolevels + :setlocal undolevels=-1 :exe "normal a \<BS>\<Esc>" - :let &undolevels = old_undolevels + :let &l:undolevels = old_undolevels :unlet old_undolevels +Note use of `&l:undolevels` to explicitly read the local value of 'undolevels' +and the use of `:setlocal` to change only the local option (which takes +precedence over the corresponding global option value). Saving the option value +via the use of `&undolevels` is unpredictable; it reads either the local value +(if one has been set) or the global value (otherwise). Also, if a local value +has been set, changing the option via `:set undolevels` will change both the +global and local values, requiring extra work to save and restore both values. + Marks for the buffer ('a to 'z) are also saved and restored, together with the text. |