Parseqsl

Parseqsl is a software library designed to parse SQL-like languages and convert queries into structured representations such as abstract syntax trees or query plans. It aims to be embeddable in database clients, data-processing pipelines, and development tools that require understanding and validation of SQL statements. The library emphasizes dialect flexibility, error reporting, and incremental parsing to support interactive use.

Parseqsl provides a grammar-driven parser generator and runtime components that can be extended to support ANSI SQL as well as common dialects such as PostgreSQL, MySQL, and SQLite. Developers can supply grammar definitions to tailor the parser to a specific subset of SQL, including features like nested queries, set operations, and window functions. The engine produces a consistent data model, enabling downstream components to perform normalization, validation, or translation to other query representations.

The project is designed with interoperability in mind, offering bindings for multiple languages and a modular architecture that separates tokenization, parsing, and semantic analysis. It supports error reporting with location metadata, helpful messages for invalid syntax, and optional recovery strategies to continue parsing after errors. Performance-focused implementations aim for linear-time parsing on typical query sizes and support streaming input for long-running pipelines.

Parseqsl is maintained as an open-source project with an emphasis on documentation, unit tests, and community contributions. It is used in various open-source data tooling and in educational contexts to illustrate parser design and SQL grammar handling.