Struct LineIndex 

pub struct LineIndex { /* private fields */ }

Maps byte offsets to line and column.

Built once from source; use for diagnostics (line/col, snippets) and formatter/compiler (e.g. “token at line 3”).

Implementations

impl LineIndex

pub fn new(source: &[u8]) -> LineIndex

Build a line index from the source. Treats \n as line break; \r\n is one break (next line starts after \n).

pub fn line_count(&self) -> u32

Number of lines (1-based; empty file = 1 line).

pub fn line_col(&self, offset: u32) -> (u32, u32)

Line and column for a byte offset (0-based line and column). Column is the byte offset from the start of the line. If offset is past end of source, returns the last line and column.

pub fn line_col_1based(&self, offset: u32) -> (u32, u32)

Human-readable line and column (1-based) for display in error messages.

pub fn line_start(&self, line: u32) -> u32

Byte offset of the first byte of the given line (0-based line index).

pub fn line_range(&self, line: u32, source_len: usize) -> Span

Byte range [start, end) for the given line (0-based). End is the start of the next line or end of source.

pub fn snippet_at(&self, source: &[u8], offset: u32) -> String

Source snippet for error reporting: the line containing offset and a caret line underneath. Uses UTF-8 when possible; invalid UTF-8 is replaced with replacement character so column alignment is approximate.

pub fn snippet_with_location(&self, source: &[u8], offset: u32) -> String

Full error snippet: “at line:col” plus the line and caret.

Trait Implementations

impl Clone for LineIndex

fn clone(&self) -> LineIndex

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LineIndex

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.