This repository is the official artifact for the SLE 2026 paper "How much does an LLM know about my programming language?". The framework systematically evaluates LLM proficiency in a programming language using ANTLR-based syntactic analysis: it extracts keywords and grammar rules from LLM-generated code and measures how much of the language's vocabulary and structure a model actually uses — even in code that fails to compile. Key features: Granular metrics: Measures Keyword/Rule Coverage and Production Validity. Partial knowledge capture: Analyzes syntactically invalid code to identify where a model's knowledge fails. Extensible: Designed to work with any language that has an ANTLR grammar. Automatic reporting: Generates a complete language coverage report as a Jupyter Notebook.