emacs_vim.Rmd

---
title: "Editing with vim keys in RStudio"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

# Intro

* Vim is a particular implementation (Windows, Mac, Linux)
* "Vim keys" paradigm widely implemented as plugins/extensions in other editors
* RStudio features Vim keys
* Promise: more efficient movement, editing

# Emacs vs Vim, or, Chorded vs Modal

* Two broad categories of historical approaches to editor commands
* "Chorded": commands are triggered by multiple keys at the same time
    * Cmd-C and Cmd-V are "chords" on macOS to copy and paste
    * Ctrl-A and Ctrl-E to move cursor to beginning, end of line
        * In Emacs [and macOS](https://jblevins.org/log/kbd)
    * TextEdit, nano, VS Code, Sublime, Atom, etc
* "Modal": commands are divided into "modes"
    * Modes are global editor states
    * Editor is in one mode at a time
    * Special keys and commands transition between modes
    * Same key sequences have different interpretation depending on mode
* Categories are loose: modal editor might have chords in a mode
    * Chorded editors can have modes 
    
# A Few Modes

* Insert mode
    * Typed keys insert themselves
    * Usually indicated visually by pipe cursor
    * Arrow keys can be used for movement
    * Enter from normal mode with `i`
* Normal mode
    * Key sequences interpreted as commands
    * Commands may change, delete, navigate
    * Enter from insert mode with `Esc`
* Command mode
    * Named actions that may accept arguments such as regexes, filenames
    * Search/replace, finding/saving files, looking up help
        * :help
    * Enter from normal mode with `:`
* Visual mode
    * The mode of visual selection
    * Enter from normal mode
    * Movement keys like normal mode
    * [Registers: named clipboards](https://www.brianstorti.com/vim-registers/)
* Visual block mode
    * Analagous to RStudio Option-click blocks/"multiple cursors"

# Normal mode

`~w~`

capitalize me

`Shift-V ~`

DOWNCASE THIS WHOLE LINE

`Ctrl-A` and `Ctrl-X`

Increment, decrement: 133

`2dw`

Delete two words

`ct,`

Change until the first comma, ok?

`ddp`

Swap two lines

* Line one
* Line two

# Text Objects
    
* Keys for applying commands relative to delimiters like `(`, `}`
* a form of [structural editing](https://en.wikipedia.org/wiki/Structure_editor)

Delete contents of vector from within:

`di(`

```{r, eval=FALSE}
c(1,2,3)
```

Change the contents of a string:

`ci"`

```{r,eval=FALSE}
old_adage <- "if you find yourself in a hole, stop digging"
```

Replace a block with its contents

`di{ va{ p gv <`

* `d`elete `i`nside block `{`
* `v`isually select `a` block `{`
* `p`ut default register contents into selection
* `gv`: start visual mode with same area as previous area
* `<` shift left

```{r,eval=FALSE}
{
  bar()
  flub()
}
```

Prepend asterisk to the following lines:

`Ctrl-V jj Shift-i * Esc`

One
Two
Three