on-parens

https://github.com/willghatch/emacs-on-parens.git

git clone 'git://github.com/willghatch/emacs-on-parens.git'


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on-parens

A wrapper for smartparens to give smartparens/paredit style commands for use in evil-normal-state.

Why?

In vi/vim/evil-mode in normal-state, the cursor is viewed as being ON a character rather than BETWEEN characters. This breaks smartparens particularly when it tries to put you past the last character of the line, since normal-state will push point back one character so it can be viewed as on the last character rather than past it. Additionally, most vim/evil movements go to the beginning of a text object, with an alternative version that goes to the end. Emacs tends to go past the end of things when it goes forward, but to the beginning when it goes back.

This provides movements for normal-state that go forward and back to specifically the beginning or end of sexps, as well as up or down.

As far as on-paren commands are concerned, if you are on a paren, you are on that sexp, and not in it. Therefore, on-parens-forward-sexp will put you on the next open paren, open string delimiter, or start of symbol on the same level. on-parens-up-sexp-end will put you on the close paren of the sexp you were inside of, etc. () is an empty list, so clearly your cursor isn't in it, it is on it.

These movements also make various insertion and deletion commands convenient – inserting at the start of the current level is <on-parens-up-sexp>a, appending at the end of the current level is <on-parens-up-sexp-end>i. Deleting a balanced sexp on the current level is d<on-parens-forward-sexp>. Deleting to the end of the level is d<on-parens-up-sexp-end>.

Commands

For movement we have:

• on-parens-forward-sexp
• on-parens-forward-sexp-end
• on-parens-backward-sexp
• on-parens-backward-sexp-end
• on-parens-up-sexp
• on-parens-up-sexp-end
• on-parens-down-sexp
• on-parens-down-sexp-end
• on-parens-forward-sexp-in-supersexp
• on-parens-backward-sexp-in-supersexp

Editing commands:

• on-parens-forward-slurp
• on-parens-forward-barf
• on-parens-backward-slurp
• on-parens-backward-barf
• on-parens-splice
• on-parens-split-supersexp
• on-parens-join-neighbor-sexp
• on-parens-kill-sexp

The editing commands probably do what you expect, they only differ from smartparens in which sexp they operate on when run on top of an opening or closing delimiter. on-parens-kill-sexp is actually pretty useless in normal state, because we have d<your keybinding for on-parens-forward-sexp here>, just like we would use dw. Numeric arguments work as expected.

Issues

It doesn't play with strings as nicely – some of the movement commands get confused when run in strings. There may be other issues – frankly I threw this together quickly just to get the functionality for myself, and I employed a few hacks. All the real legwork is done in smartparens, however, so there is some mature code underneath this plugin. This plugin is mostly to alter the functionality of annoying corner cases where the philosophies of emacs and vim/evil butt heads.

Recommendations

• Use this with emacs-repeatable-motion to get repeatable versions, bind the repeat command to a single key, and the movement commands to a two-key combo. Also, since I already had the framework in repeatable-motion to declare the motions with the proper inclusivity for evil-mode, I didn't do that in this plugin (it doesn't make a huge difference, but it's nice to have it working right).
• I recommend adding evil-surround to deal with wrapping expressions or the region in parens, or changing the type of delimiter things are wrapped in.
• If you want to keep dd, D, etc from killing your paren balance, you can try evil-smartparens, which does checking on such commands to be sure they play nice with the parens. Alternatively, instead of D you can use d<on-parens-up-sexp> to accomplish the same, and still have D around (sometimes obliterating paren balance and rebuilding can just be easier, so it's nice to have the normal functionality too).

Install

Requires Emacs version 24.

Install from Melpa or clone this repo into your load path and run (require 'on-parens) in your initialization.

License

GPLv3+

Enjoy