It can happen —specially when learning Vem, but also later too— that you mistakenly press a different key than the one you really intended to use. Since every key has an associated action, you may end up in an unexpected place of your document or modifying it in an unintentional way.
If this happens, just jump back to where you were or undo the latest action with:
undo last change
jump to previous position
q undoes the last change and jumps back too, so you can use that one to ensure that you didn't modify anything by mistake and if the latest change was correct you can just redo it with Q.
In any case, you can also check the timestamps of the latest changes to see, at any time, when the last change to the document happened:
If you find that a key, or a key combination, does something unexpected, it can be that one plugin is overriding Vem's default behavior. Most plugins define their custom keyboard mappings using the <leader> key (usually \) as prefix or allow you to define your own mappings to avoid conflicts with existing key mappings. However, if they define a new behavior for a key that shadows Vem's default one, then it may be difficult to detect until you try use such key.
In any case, if you find a key that performs a different action to what you expect, you can check how its action was mapped with:
:verbose map KEY
where KEY is:
A lower or uppercase letter.
A Ctrl key combination, specified as <C-f>, <C-t>, ...
A special key: <Tab>, <Space>, <Enter> or <BS> (for backspace).
map will list mappings in normal and visual modes, but you also query the mappings of a specific mode with:
nmap for normal mode
xmap for visual mode
imap for insert mode
The output of the command is something like:
x f <Plug>vem_change- Last set from /usr/local/share/vem10/src/mappings.vim line 226 n f <Plug>vem_change_word- Last set from /usr/local/share/vem10/src/mappings.vim line 221
The first column is the mode (n: normal, x: visual, i: insert), the second the key and the third the associated action. Finally, a line is included that specifies where the mapping was defined. This can help to identify which plugin is redefining a key.
All actions set by Vem are prefixed with <Plug>vem.
You can get help about any topic using the command line. Just type:
With Tab you can autocomplete the topic string.
You can use the help command to find more information about configuration options, commands or mappings. For example, you can get more information about the :sort ex-command with:
After executing this command, the screen will be split showing your current document and a new window displaying the contents of help. This is a regular editor window and you can browse its contents with the usual movement keys. In particular, you'll see that some terms are highlighted. Vim help files use tags to hyperlink documents together. Therefore, you can:
jump to a topic by placing the cursor on top of a highlighted term and pressing Space o
jump back to the previous topic with Space i
close the window with x