Module location 

Location tracking for XSD parsing

This module provides accurate source location tracking using byte offsets from quick-xml. It supports three retention modes to balance memory usage vs. error reporting fidelity:

• Retain: Keep full source text (default, ~200KB per 200KB schema)
• DropText: Keep only line starts (~10KB per 200KB schema)
• DropAll: No location info (minimal memory)

Per XSD_PARSER_DESIGN.md:

• Use quick-xml’s buffer_position() for byte offsets
• Build line_starts table once per document
• Handle CR, LF, and CRLF line endings correctly
• Column calculation counts UTF-8 characters, not bytes

Structs

CompactSourceMap

Compact source map when text is dropped (DropText mode)

SourceLocation

Line/column location for error reporting (1-based)

SourceMap

Per-document source mapping for line/column resolution

SourceRef

Reference to a location within a schema document

SourceSpan

Byte range within a document

Enums

SourceMapStorage

Centralized source map storage with configurable retention

SourceRetention

Source buffer retention policy

Functions

build_line_starts

Build line start index from source bytes