Struct LineIndex 

pub struct LineIndex { /* private fields */ }

Pre-computed line index for O(log n) line/column lookups.

Instead of iterating from the start of the file for each lookup, we build an index of line start positions once and use binary search.

Implementations

impl LineIndex

pub fn new(source: &str) -> Self

Build a line index from source text.

Time: O(n) where n is the length of the source Space: O(lines) for storing line start positions

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

Convert a byte offset to (line, column), both 1-indexed.

Time: O(log n) where n is the number of lines

Panics

Does not panic; returns the last valid position if offset is past end.

pub fn line_start(&self, line: usize) -> Option<usize>

Get the byte offset where a line starts (1-indexed line number).

pub fn line_count(&self) -> usize

Get the total number of lines.

pub fn byte_offset(&self, line: usize, column: usize) -> Option<usize>

Convert (line, column) to byte offset. Both are 1-indexed.

Returns None if line is out of bounds or if the result would overflow. Column is clamped to line length if too large.