Compatibility

Alto Code Highlight follows semantic versioning for its documented entry points and extension contracts. Patch and minor releases preserve their signatures and behavior throughout the 1.x series.

Exceptions

LanguageNotFoundException reports an unknown language identifier. ParseException reports source that a semantic parser cannot process. Both are part of the supported exception contract.

Applications may catch those exceptions individually, or catch the package exception interface when the same recovery applies to every highlighting failure. Keep the original source visible when highlighting is optional.

Supported boundary

The compatibility promise covers:

• generated element structure and documented CSS classes;
• source escaping;
• registered language identifiers;
• semantic Scope values;
• documented public signatures;
• the language and theme extension contracts.

The following details are implementation details:

• concrete lexer, parser, state, and token classes inside a built-in language;
• exact whitespace inside generated HTML;
• private methods and undocumented types;
• test fixtures, documentation tooling, and generated showcase assets.

Those details may change in a minor or patch release when documented behavior stays compatible. Review the Languages and Themes pages for the public extension contracts.