To extend parsing without rebuilding, what approach should you take?

• A. Design a custom parser.
• B. Apply updates to prebuilt parser.
• C. Implement a parser extension on top of the prebuilt parser.
• D. Implement middleware to modify data structure.

Answer: (C)

Extending parsing without rebuilding is achieved by implementing a parser extension on top of the prebuilt parser. This means you add new behavior by plugging into the existing parsing pipeline rather than replacing or rebuilding the whole parser. The extension uses the framework’s extension points to introduce extra tokens, grammar rules, or AST transformations, so the base parser continues handling the established grammar while the extension adds the new capabilities. This approach preserves compatibility, reduces risk, and allows incremental feature additions.

Why this fits best: you gain the ability to recognize and process new constructs without rewriting the entire parser. The prebuilt parser handles the proven grammar; the extension augments it in a modular way, making changes safer and easier to deploy.

Why the others don’t fit as well: designing a custom parser would require building a new parsing engine from scratch, which defeats the goal of extending without rebuilding. applying updates to the prebuilt parser may modify the core engine rather than provide a clean extension layer, potentially affecting existing behavior and requiring redeployment. implementing middleware to modify the data structure operates after parsing, so it doesn’t extend how parsing is performed or handle new syntax—it only changes the output after parsing.