Struct PositionMapper 

pub struct PositionMapper { /* private fields */ }

Line ending detection and UTF-16 position mapping for LSP compliance. Centralized position mapper using rope for efficiency.

Converts between byte offsets (used by the parser) and LSP positions (line/character in UTF-16 code units) while handling mixed line endings.

Examples

use perl_position_tracking::PositionMapper;

let text = "my $x = 1;\nmy $y = 2;\n";
let mapper = PositionMapper::new(text);

// Convert byte offset 0 → LSP position (line 0, char 0)
let pos = mapper.byte_to_lsp_pos(0);
assert_eq!(pos.line, 0);
assert_eq!(pos.character, 0);

// Second line starts at byte 11
let pos = mapper.byte_to_lsp_pos(11);
assert_eq!(pos.line, 1);
assert_eq!(pos.character, 0);

Implementations

impl PositionMapper

pub fn new(text: &str) -> PositionMapper

Create a new position mapper from text.

Detects line endings and builds an internal rope for efficient position conversions.

Examples

use perl_position_tracking::PositionMapper;

let mapper = PositionMapper::new("print 'hello';\n");
let pos = mapper.byte_to_lsp_pos(6);
assert_eq!(pos.line, 0);
assert_eq!(pos.character, 6);

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

Update the text content

pub fn apply_edit(&mut self, start_byte: usize, end_byte: usize, new_text: &str)

Apply an incremental edit

pub fn lsp_pos_to_byte(&self, pos: WirePosition) -> Option<usize>

Convert LSP position to byte offset.

Takes a line/character position (UTF-16 code units, as specified by the LSP protocol) and returns the corresponding byte offset in the source.

Examples

use perl_position_tracking::{PositionMapper, WirePosition};

let mapper = PositionMapper::new("my $x = 1;\nmy $y = 2;\n");
// Line 1, character 3 → "$y"
let byte = mapper.lsp_pos_to_byte(WirePosition { line: 1, character: 3 });
assert_eq!(byte, Some(14));

pub fn byte_to_lsp_pos(&self, byte_offset: usize) -> WirePosition

Convert byte offset to LSP position.

Returns line/character (UTF-16 code units) suitable for LSP responses.

Examples

use perl_position_tracking::PositionMapper;

let mapper = PositionMapper::new("sub foo {\n    return 1;\n}\n");
let pos = mapper.byte_to_lsp_pos(14);  // points into "return"
assert_eq!(pos.line, 1);
assert_eq!(pos.character, 4);

pub fn text(&self) -> String

Get the text content

pub fn slice(&self, start_byte: usize, end_byte: usize) -> String

Get a slice of text

pub fn len_bytes(&self) -> usize

Get total byte length

pub fn len_lines(&self) -> usize

Get total number of lines

pub fn lsp_pos_to_char(&self, pos: WirePosition) -> Option<usize>

Convert LSP position to char index (for rope operations)

pub fn char_to_lsp_pos(&self, char_idx: usize) -> WirePosition

Convert char index to LSP position

pub fn is_empty(&self) -> bool

Check if empty

pub fn line_ending(&self) -> LineEnding

Get line ending style