helix/book/src/usage.md

# Usage

(Currently not fully documented, see the [keymappings](./keymap.md) list for more.)

## Surround

Functionality similar to [vim-surround](https://github.com/tpope/vim-surround) is built into
helix. The keymappings have been inspired from [vim-sandwich](https://github.com/machakann/vim-sandwich):

![surround demo](https://user-images.githubusercontent.com/23398472/122865801-97073180-d344-11eb-8142-8f43809982c6.gif)

- `ms` - Add surround characters
- `mr` - Replace surround characters
- `md` - Delete surround characters

`ms` acts on a selection, so select the text first and use `ms<char>`. `mr` and `md` work
on the closest pairs found and selections are not required; use counts to act in outer pairs.

It can also act on multiple seletions (yay!). For example, to change every occurance of `(use)` to `[use]`:

- `%` to select the whole file
- `s` to split the selections on a search term
- Input `use` and hit Enter
- `mr([` to replace the parens with square brackets

Multiple characters are currently not supported, but planned.

## Textobjects

Currently supported: `word`, `surround`.

![textobject-demo](https://user-images.githubusercontent.com/23398472/124231131-81a4bb00-db2d-11eb-9d10-8e577ca7b177.gif)

- `ma` - Select around the object (`va` in vim, `<alt-a>` in kakoune)
- `mi` - Select inside the object (`vi` in vim, `<alt-i>` in kakoune)

| Key after `mi` or `ma` | Textobject selected      |
| ---                    | ---                      |
| `w`                    | Word                     |
| `(`, `[`, `'`, etc     | Specified surround pairs |

Textobjects based on treesitter, like `function`, `class`, etc are planned.