public Optional<String> maybeVisit(JsonNode schema, String baseName, String name) {
            var typeText = getTypeText(schema);
            var formatText = getFormatText(schema);

            if ((typeText == null || typeText.equals("string"))
                    && formatText != null && formatText.matches("^uuid[1-5]?$")) {
                var rule = addPrimitive(name.equals("root") ? "root" : formatText, PRIMITIVE_RULES.get("uuid"));
                return Optional.of(rule);
            }

            return Optional.empty();
        }
Converts a JSON Schema to a GBNF grammar to be used for structured output with llama.cpp.
It is a port of Python implementation from llama.cpp repository.
Current implementation doesn't support regex patterns, resolving $ref or fetching schemas from URLs.
The plan is to replace this with C++ implementation from llama.cpp though JNI.
model-integration/src/main/java/ai/vespa/llm/clients/JsonSchemaToGrammar.java