Module span 

Source location tracking for error reporting.

Provides types for tracking positions within source code:

• BytePos: A byte offset into source text
• Span: A range of bytes representing a source region
• Spanned<T>: A value paired with its source location

Structs

BytePos

A byte position in source code.

Span

A span representing a range of source code.

Spanned

A value with an associated source span.

Functions

get_line

Returns the line containing a position.

line_col

Computes line and column from a byte position.

line_number

Returns the line number (1-indexed) for a position.