UQL Parser Online

The UQL Parser Online converts UQL queries into a structured Abstract Syntax Tree (AST) and exposes token streams for inspection. It serves data engineers, analytics engineers, BI developers, and QA engineers who author or validate UQL expressions. Core capabilities include lexical analysis of identifiers, operators, literals, and comments; a formal grammar to produce a deterministic AST; and deterministic error reporting with position information. It supports standard UQL constructs such as SELECT, FILTER, AGGREGATE, and LIMIT, plus optional extensions for schema-aware validation. It returns both raw tokens and a parse tree to aid debugging and test generation.
Conceptually, the tool runs in three stages: lexing, parsing, and AST generation. The lexer emits a token stream with type and position, the parser applies the UQL grammar to build an AST, and the result is a parse_tree, tokens, and any syntax errors. Optional inputs can supply a data_schema to enable semantic checks, and parse options to relax or tighten constraints. Output is designed for automated pipelines: the AST can feed compilers or BI pipelines, and tokens assist in tracing the parsing process.
Use cases include validating user-generated queries before execution, transforming UQL into intermediate representations for analytics tooling, and debugging complex expressions that combine joins, groupings, and windowing. Unique value comes from real-time tokenization alongside AST output, the ability to feed an optional schema for semantic hints, and structured error data with precise locations. The tool is language-aware, supports English error messages, and can be integrated into CI pipelines for query-quality gates.