gsh/input/key

The key module defines the domain model for terminal input events.

When the TTY operates in raw mode, user keystrokes—ranging from single UTF-8 graphemes to multi-byte ANSI escape sequences (e.g., arrow keys, word navigation)— are captured as raw byte streams. This module provides an algebraic data type to abstract low-level TTY sequences into structured events for the editor.

Types

Key

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Represents a parsed keystroke or control sequence captured from raw terminal input.

pub type Key {
  Character(String)
  Enter
  Backspace
  Tab
  ArrowUp
  ArrowDown
  ArrowLeft
  ArrowRight
  CtrlL
  End
  Home
  CtrlLeft
  CtrlRight
  Unknown
}

Constructors

```
Character(String)
```
A printable UTF-8 character grapheme (e.g., "a", "Z", "5", " ").
```
Enter
```
The Return/Enter key, signaling prompt submission or line insertion.
```
Backspace
```
The Backspace key, used to remove the character grapheme preceding the cursor.
```
Tab
```
The Tab key, used to trigger predictive autocompletion and candidate grid menus.
```
ArrowUp
```
The Up Arrow key, used for upward 2D cursor traversal or history retrieval.
```
ArrowDown
```
The Down Arrow key, used for downward 2D cursor traversal or history retrieval.
```
ArrowLeft
```
The Left Arrow key, used to move the cursor backward by one grapheme.
```
ArrowRight
```
The Right Arrow key, used to move the cursor forward by one grapheme.
```
CtrlL
```
The Ctrl+L chord, triggering a screen clear while preserving active buffer state.
```
End
```
The Home key (or Fn+Left), repositioning the cursor to the start of the current line.
```
Home
```
The End key (or Fn+Right), repositioning the cursor to the end of the current line.
```
CtrlLeft
```
The Ctrl+Left chord, jumping the cursor backward across word boundaries.
```
CtrlRight
```
The Ctrl+Right chord, jumping the cursor forward across word boundaries.
```
Unknown
```
Unrecognized or unhandled ANSI escape sequences (e.g., function keys, scroll lock).