Motivation
While disabling Evil in holy-mode makes its implementation shorter and
sounds elegant on the paper, in practice it puts a big burden on the
configuration parts which need to know if Evil is enable or not. This is
a bad separation of concerns and the bunch of fixes that we were forced
to do in the past weeks shows this issue. Those fixes were about
removing the knowledge of the activation of Evil by implementing new
dispatching functions to be used by layers, this is cumbersome and makes
Spacemacs layer configuration more subtle which is not good. There was
additional bad consequences of the removal of Evil state like the
impossibility to use Evil lisp state or iedit states, or we would have
been forced to implement a temporary activation of Evil which is
awkward.
Instead I reintroduce Evil as the central piece of Spacemacs design thus
Evil is now re-enabled in holy-mode. It provides the abstraction we need
to isolate editing styles and be able to grow the Spacemacs
configuration coverage sanely. Layers don't need to check whether the
holy mode is active or not and they don't need to know if Evil is
available (it is always available). We also don't need to write
additional dispatching functions, this is the job of Evil, and I think
it provides everything for this. Ideally configuration layer should be
implemented with only Evil in mind and the holy-mode (and hybrid-mode)
should magically make it work for Emacs style users, for instance we can
freely use `evil-insert-state` anywhere in the code without any guard.
Evil is now even more part of Spacemacs, we can really say that
Spacemacs is Emacs+Evil which is now an indivisible pair. Spacemacs
needed this stable API to continue on the right track.
While these changes should be rather transparent to the user, I'm sorry
for this experimental period, I failed to see all the implications of
such a change, I was just excited about the possibility to make Evil
optional. The reality is that Spacemacs has to embrace it and keep its
strong position on being Emacs+Evil at the core.
Implementation
- insert, motion and normal states are forced to emacs state using an
advice on `evil-insert-state`, `evil-motion-state` and
`evil-normal-state` respectively. These functions can be used freely in
the layer configuration.
- A new general hook `spacemacs-editing-style-hook` allow to hook any
code that need to be configured based on the editing style. Functions
hooked to this hook takes the current style as parameter, this
basically generalize the hook used to setup hjkl navigation bindings.
- ESC has been removed from the emacs state map.
- Revert unneeded changes
- Revert "evil: enter insert-state only from normal-state"
commit bdd702dfbe.
- Revert "avoid being evil in deft with emacs editing style"
commit f3a16f49ed.
Additional changes
All editing style packages have been moved to a layer called
`spacemacs-editing-styles`
Notes
I did not have time to attack hybrid mode, I should be able to do it
later.
Make use of new evil variable evil-disable-insert-state-bindings. This
is better because we are not copying evil code to get hybrid state to
work. We should not need to worry about tracking upstream evil changes
with this version of hybrid mode.
The only effect I can think of with this change is that there is no
longer a distinct hybrid-map, since there is no longer a distinct hybrid
state. This means that, for example, (evil-define-key 'hybrid ...)
will throw an error. You can either use (evil-define-key 'insert ...) or
the preferred (global-set-key ...). The latter is preferred because the
purpose of hybrid mode is to not interfere with Emacs bindings in insert
state.
Use post-init-evil function to load
It's a bit safer than with-eval-after-load, in case evil gets loaded
before its init function is called.
Add entry and exit hooks
Add temporary wrapper to evil-define-key
This is so that calls like (evil-define-key 'hybrid ...) do not fail
after switching over. Instead issue a warning for all such instances and
bind using define-key instead.
Also define evil-hybrid-state-map and make it the parent of
evil-insert-state-map this will prevent calls like (define-key
evil-hybrid-state-map ...) from failing.
These are both temporary and are only intended to smooth the transition
to the new version of hybrid-mode.
