Whenever a new history node is committed after some undo steps, instead
of creating a new branch in the undo graph, we first append the inverse
modifications starting from the end of the undo list up to the current
position before adding the new node.
For example let's assume that the undo history is A-B-C, that a single undo
has been done (bringing us to state B) and that a new change D is committed.
Instead of creating a new branch starting at B, we add the inverse of C
(noted ^C) at the end, and D afterwards. This results in the undo history
A-B-C-^C-D. Since C-^C collapses to a null change, this is equivalent to
A-B-D but without having lost the C branch of the history.
If a new change is committed while no undo has been done, the new history
node is simply appended to the list, as was the case previously.
This results in a simplification of the user interaction, as two bindings
are now sufficient to walk the entire undo history, as opposed to needing
extra bindings to switch branches whenever they occur.
The <a-u> and <a-U> bindings are now free.
It also simplifies the implementation, as the graph traversal and
branching code are not needed anymore. The parent and child of a node are
now respectively the previous and the next elements in the list, so there
is no need to store their ID as part of the node.
Only the committing of an undo group is slightly more complex, as inverse
history nodes need to be added depending on the current position in the
undo list.
The following article was the initial motivation for this change:
https://github.com/zaboople/klonk/blob/master/TheGURQ.md
From the issue:
> It often happens to me that I carefully craft a selection with multiple
> cursors, ready to make changes elegantly, only to completely mess it
> up by pressing a wrong key (by merging the cursors for example). Being
> able to undo the last selection change (even if only until the previous
> buffer change) would make this much less painful.
Fix this by recording selection changes and allowing simple linear
undo/redo of selection changes.
The preliminary key bindings are <c-h> and <c-k>.
Here are some other vacant normal mode keys I considered
X Y
<backspace> <minus>
# ^ =
<plus> '
unfortunately none of them is super convenient to type. Maybe we
can kick out some other normal mode command?
---
This feature has some overlap with the jump list (<c-o>/<c-i>) and
with undo (u) but each of the three features have their moment.
Currently there's no special integration with either peer feature;
the three histories are completely independent. In future we might
want to synchronize them so we can implement Sublime Text's "Soft
undo" feature.
Note that it is possible to restore selections that predate a buffer
modification. Depending on the buffer modification, the selections
might look different of course. (When trying to apply an old buffer's
selection to the new buffer, Kakoune computes a diff of the buffers
and updates the selection accordingly. This works quite well for
many practical examples.)
This makes us record the full history of all selections for each
client. This seems wasteful, we could set a limit. I don't expect
excessive memory usage in practice (we also keep the full history of
buffer changes) but I could be wrong.
Closes#898
`x` is often criticized as hard to predict due to its slightly complex
behaviour of selecting next line if the current one is fully selected.
Change `x` to use the previous `<a-x>` behaviour, and change `<a-x>` to
trim to fully selected lines as `<a-X>` did.
Adapt existing indentation script to the new behaviour
Fixes issue #2377 by removing the ability to escape backticks in backticks in compliance with asciidoc's behaviour. Adjusted hooks.asciidoc, keys.asciidoc, and command-parsing.asciidoc to match accordingly.
Similarly to the <semicolon> key, make it easier to write
`:execute-keys` commands by replacing <percent> with `%`.
Highlighters can keep escaping the sign when regular expressions are
not quoted, but built-in scripts that use `%` as an editing primitive
have been modified to use the named key, for clarity.
The fact that punctuation characters can act as surrounding
delimiters is a useful behavior but not obvious.
This "hidden" text-object feature deserves to be described explicitely.
The GitHub issue referenced below describes the default behavior of
the 'm' key in a way that was unknown to me. As the issue says,
"'m' is a pretty misunderstood key", and goes on to describe how
the documentation makes it sound as if the cursor must be on the
matching character before 'm' will work. However, this is not true;
pressing 'm' will jump forward to "select the next sequence enclosed
in balanced chars". This patch updates the documentation so that it
describes that behavior.
GitHub-Issue: #2425
Special-thanks: Delapouite
Add <c-w> and <a-d> (along with <c-W> and <a-D> that work on WORDs),
and <c-y> which pastes the transient clipboard contant (which saves
big erase, such as word erase and line end/begin erase).
Fixes#2355
In the end, no better solution materialized so far, and custom
Kakoune line editing bindings are hard to remember. Using well
known readline bindings seems just more convenient.
Closes#800, although it does not contain all the binding proposed
by it (I might accept a few additional ones, such as <c-w>, but not
too much, I still see that as a hack pending a nicer solution).
Because keyboard layouts vary, the shift-modifier `<s-…>` is only supported
for special keys (like `<up>` and `<home>`) and for ASCII lowercase where
we assume the shift-modifier just produces the matching uppercase character.
Even that's not universally true, since in Turkish `i` and `I` are not an
uppercase/lowercase pair, but Kakoune's default keyboard mappings already
assume en-US mappings for mnemonic purposes.
Mappings of the form `<s-x>` are normalized to `<X>` when `x` is an ASCII
character. `<backtab>` is removed, since we can now say `<s-tab>`.
