Struct LineBuffer 

pub struct LineBuffer { /* private fields */ }

Text buffer with cursor tracking for line editing operations.

Manages the actual text being edited and the cursor position within it. Supports UTF-8 text and provides methods for character/word manipulation.

This struct is typically not used directly - instead use LineEditor which provides the high-level editing interface.

Implementations

impl LineBuffer

pub fn new(capacity: usize) -> Self

Creates a new line buffer with the specified capacity.

Arguments

• capacity - Initial capacity for the internal buffer in bytes

Examples

use editline::LineBuffer;

let buffer = LineBuffer::new(1024);
assert!(buffer.is_empty());

pub fn clear(&mut self)

Clears the buffer and resets the cursor to the start.

pub fn len(&self) -> usize

Returns the length of the buffer in bytes.

Note: For UTF-8 text, this is the byte count, not the character count.

pub fn is_empty(&self) -> bool

Returns true if the buffer is empty.

pub fn cursor_pos(&self) -> usize

Returns the current cursor position in bytes from the start.

pub fn as_str(&self) -> Result<&str>

Returns the buffer contents as a UTF-8 string slice.

Errors

Returns Err if the buffer contains invalid UTF-8.

pub fn as_bytes(&self) -> &[u8]

Returns the buffer contents as a byte slice.

pub fn insert_char(&mut self, c: char)

Inserts a character at the cursor position, moving the cursor forward.

Supports UTF-8 characters. The cursor advances by the byte length of the character.

pub fn delete_before_cursor(&mut self) -> bool

Deletes the character before the cursor (backspace operation).

Returns true if a character was deleted, false if the cursor is at the start.

pub fn delete_at_cursor(&mut self) -> bool

Deletes the character at the cursor (delete key operation).

Returns true if a character was deleted, false if the cursor is at the end.

pub fn move_cursor_left(&mut self) -> bool

Moves the cursor one position to the left.

Returns true if the cursor moved, false if already at the start.

pub fn move_cursor_right(&mut self) -> bool

Moves the cursor one position to the right.

Returns true if the cursor moved, false if already at the end.

pub fn move_cursor_to_start(&mut self) -> usize

Moves the cursor to the start of the line.

Returns the number of positions the cursor moved.

pub fn move_cursor_to_end(&mut self) -> usize

Moves the cursor to the end of the line.

Returns the number of positions the cursor moved.

pub fn move_cursor_word_left(&mut self) -> usize

Moves the cursor to the start of the previous word.

Words are defined as sequences of alphanumeric characters and underscores. Returns the number of positions the cursor moved.

pub fn move_cursor_word_right(&mut self) -> usize

Moves the cursor to the start of the next word.

Words are defined as sequences of alphanumeric characters and underscores. Returns the number of positions the cursor moved.

pub fn delete_word_left(&mut self) -> usize

Deletes the word to the left of the cursor (Alt+Backspace operation).

Returns the number of bytes deleted.

pub fn delete_word_right(&mut self) -> usize

Deletes the word to the right of the cursor (Ctrl+Delete operation).

Returns the number of bytes deleted.

pub fn load(&mut self, text: &str)

Loads text into the buffer, replacing existing content.

The cursor is positioned at the end of the loaded text. Used internally for history navigation.