156 lines
6.2 KiB
Plaintext
156 lines
6.2 KiB
Plaintext
Kakoune design
|
|
==============
|
|
|
|
This document describes the design goals for Kakoune, including rationales.
|
|
|
|
Interactivity
|
|
-------------
|
|
|
|
Unlike Vim, Kakoune does not have an underlying line-oriented editor, and
|
|
is always expected to be used in an interactive (i.e. with the edited text
|
|
being displayed in real time) fashion. That should not prevent Kakoune from
|
|
being used non interactively (executing macro for example), but priority
|
|
should be given to ease of interactive use.
|
|
|
|
Limited scope
|
|
-------------
|
|
|
|
Kakoune is a code editor. It is not an IDE, not a file browser, not a word
|
|
processor and not a window manager. It should be very efficient at editing code,
|
|
and should, as a side effect, be very efficient at editing text in general.
|
|
|
|
Composability
|
|
-------------
|
|
|
|
Being limited in scope to code edition should not isolate Kakoune from its
|
|
environment. On the contrary, Kakoune is expected to run on a Unix-like
|
|
system, along with a lot of text-based tools, and should make it easy to
|
|
interact with these tools.
|
|
|
|
For example, sorting lines should be done using the Unix sort command, not
|
|
with an internal implementation. Kakoune should make it easy to do that,
|
|
hence the +|+ command for piping selected text through a filter.
|
|
|
|
The modern Unix environment is not limited to text filters, most people use
|
|
a graphical interface nowadays, and Kakoune should be able to take advantage
|
|
of that, without hindering text mode support. For example Kakoune supports
|
|
multiple clients on the same editing session, so that multiple windows can
|
|
be used, letting the system window manager handle its responsibilities such
|
|
as tiling or tabbing.
|
|
|
|
Orthogonality
|
|
-------------
|
|
|
|
Kakoune features should be as orthogonal as possible, for example, in Vim,
|
|
there are multiple ways for modifying the buffer: Through normal/insert
|
|
mode, command mode, and Vim scripts. In Kakoune, modifying the buffer is the
|
|
normal/insert mode job.
|
|
|
|
That means there should be clear separation of concerns between modes:
|
|
|
|
* normal mode is for manipulating the selection and the selection contents.
|
|
|
|
* insert mode is for interactive insertion into the buffer.
|
|
|
|
* command mode is for non-editing features (opening a file, setting
|
|
options...).
|
|
|
|
Orthogonality is an ideal, and should not prevent common sense pragmatism,
|
|
the +gf+ and +ga+ commands are not strictly selection manipulation ones,
|
|
but fit nicely with other +goto+ commands, and hence are acceptable in
|
|
normal mode even though they could arguably be moved to command mode.
|
|
|
|
Modes should be orthogonal, and commands in modes should be as well. For
|
|
example, Vim uses +d+ and +x+ for very similar things: deleting text. In
|
|
Kakoune only +d+ exists, and the design ensures that +x+ is not needed.
|
|
|
|
Speed
|
|
-----
|
|
|
|
Kakoune should be fast, fast to use, as in a lot of editing in a few
|
|
keystrokes, and fast to execute.
|
|
|
|
* Vim is the benchmark here, most editing tasks should be doable in less
|
|
or the same number of keys.
|
|
|
|
* Kakoune be designed with asynchronicity in mind, launching a background
|
|
process and using its result when available should not block the editor.
|
|
|
|
* Kakoune should be implemented with speed in mind, a slow editor is a
|
|
useless one.
|
|
|
|
Simplicity
|
|
----------
|
|
|
|
Simplicity is nice, simplicity correlates with orthogonality and speed, and makes
|
|
things easier to understand, bugs easier to fix, and code easier to change.
|
|
|
|
* *No threading*: multithreading is a hard problem, and is not well suited
|
|
to a text editor:
|
|
|
|
- Either we want a direct result, and we need to be synchronous with
|
|
the user, so getting a 4x speed up is meaningless, we need to have an
|
|
algorithm which appears instantaneous the user.
|
|
|
|
- Or we want an asynchronous result, and then the processing is best left
|
|
to a helper command which can be reused with other Unix tools.
|
|
|
|
* *No binary plugins*: shared object by themselves add a lot of
|
|
complexity. Plugins add another interface to Kakoune, and goes against
|
|
orthogonality. The +%sh{ ... }+ and socket interface should be made good
|
|
enough for most plugin use cases.
|
|
|
|
- It is better to write Kakoune-independent helper tools (intelligent
|
|
code completer, source code navigation programs) that can interact with
|
|
Kakoune through the shell than write them in a plugin.
|
|
|
|
* *No integrated scripting language*: for the same reason as binary plugins.
|
|
|
|
* *Limited smartness*: Kakoune should not try to be too smart, being smart
|
|
is often unpredictable for the user, and makes things context dependent.
|
|
When Kakoune tries to be smart, it should provide the alternative, 'non
|
|
smart' version (+\*+ tries to detect word boundaries on the selection, but
|
|
+alt-*+ permits to avoid this behavior).
|
|
|
|
Unified interactive use and scripting
|
|
-------------------------------------
|
|
|
|
As both an effect of Orthogonality and Simplicity, normal mode is *not*
|
|
a layer on top of a text editing language layer (normal mode keys are
|
|
*not* bound to text editing commands), normal mode *is* the text editing
|
|
language.
|
|
|
|
That means there is no +delete-selected-text+ command that +d+ is bound
|
|
to, +d+ *is* the +delete selected text+ command.
|
|
|
|
This permits to have scripting use case and interactive use cases share
|
|
the same text editing language. Both use normal mode to express complex
|
|
edition.
|
|
|
|
Besides promoting simplicity by avoiding the introduction of another
|
|
layer, this helps ensure the interactive editing language is as expressive
|
|
as possible as we need to make it able to handle complex use cases,
|
|
such as indentation hooks.
|
|
|
|
Language agnostic
|
|
-----------------
|
|
|
|
Kakoune should not be tailored for writing in a specific programming
|
|
language. Support for different languages should be provided by a kak script
|
|
file, built-in language support should be avoided.
|
|
|
|
Self documenting
|
|
----------------
|
|
|
|
Kakoune should be able to document its features, live documentation along
|
|
with an extensive suggestion/completion system provides the discoverability
|
|
which is often lacking in non GUI tools. Documentation should as much as
|
|
possible be integrated with the code so that it stays up to date.
|
|
|
|
Vim compatibility
|
|
-----------------
|
|
|
|
Kakoune is inspired by Vim, and should try to keep its commands close to
|
|
Vim's if there are no compelling reasons to change. However self-consistency
|
|
is more important than Vim compatibility.
|