Implementing a Custom Query Language with Python and Apache Spark
SMRTR summary
Building a custom query language sounds daunting, but this walkthrough shows how to implement EHQL — a domain-specific language for vehicle maintenance queries — using Python, Lark, and Apache Spark. It covers grammar definition in EBNF, handling significant indentation with a postlexer, constructing parse trees with LALR(1), and transforming those trees into Spark DataFrame queries step by step.
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