Struct SourceMap 

pub struct SourceMap { /* private fields */ }

Pre-computed index of line-start byte offsets for a source string.

Construction is O(n) in the source length. Each lookup is O(log n) in the number of lines (binary search), which is effectively O(1) for typical files.

Implementations

impl SourceMap

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

Build an index from the given source text.

pub fn empty() -> Self

A no-op map for callers that never query line/column positions. Returned by parse_arena_raw. offset_to_line_col on an empty map returns LineCol { line: 0, col: offset }.

pub fn line_count(&self) -> usize

Total number of lines in the source.

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

Byte offset where the given 0-based line starts. Returns None if the line is out of range.

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

Convert a byte offset to a 0-based line/column.

If offset is past the end of the source, the position is clamped to the last line.

pub fn span_to_line_col(&self, span: Span) -> LineColSpan

Convert a Span to a start/end LineColSpan.

pub fn line_col_to_offset(&self, lc: LineCol) -> Option<u32>

Convert a 0-based line/column back to a byte offset. Returns None if the line is out of range.