Parinfer simplifies Lisp code editing by automatically managing parentheses, brackets, and indentation. It offers two modes: "Paren Mode," where indentation dictates structure and Parinfer adjusts parentheses accordingly, and "Indent Mode," where parentheses define the structure and Parinfer corrects indentation. This frees the user from manually tracking matching delimiters, allowing them to focus on the code's logic. Parinfer analyzes the code as you type, instantly propagating changes and offering immediate feedback about structural errors, leading to a more fluid and less error-prone coding experience. It's adaptable to different indentation styles and supports various Lisp dialects.
Parinfer, introduced by Shaun Lebron, proposes a novel approach to editing Lisp code, aiming to simplify the traditionally cumbersome process of managing parentheses. It operates on the principle of maintaining structural consistency, automatically adjusting parentheses as the user types code, eliminating the need for manual insertion, deletion, or matching.
The system works by allowing developers to focus on either the content of their code (referred to as "Paren Mode") or the structure represented by parentheses (referred to as "Indent Mode"). In Paren Mode, users type code as they normally would, adding and removing characters. Parinfer intercepts these changes and intelligently adjusts the surrounding parentheses to maintain proper syntactic balance. This eliminates the common errors associated with mismatched or missing parentheses, allowing for a more fluid and uninterrupted coding experience.
Conversely, in Indent Mode, the user manipulates the indentation of the code, which Parinfer interprets as instructions for modifying the parenthetical structure. Changes in indentation will automatically insert, delete, or reposition parentheses to reflect the intended nesting of expressions. This offers an alternative approach to structuring code, leveraging the visual cues of indentation for greater clarity and ease of manipulation, especially in deeply nested expressions.
Parinfer supports a wide range of Lisp dialects, including Clojure, Scheme, Common Lisp, and Racket, demonstrating its adaptability and broad applicability within the Lisp ecosystem. It is not tied to any specific editor, being implemented as a library that can be integrated into various editing environments. This portability makes it accessible to a wider audience of Lisp programmers, regardless of their preferred tools.
The system strives to be minimally invasive, ensuring that edits are predictable and understandable. It operates on a clear set of rules that govern the interaction between typed characters, indentation, and the resulting parenthetical structure. This predictability is crucial for building trust in the system and allowing users to confidently rely on Parinfer to handle the intricacies of parenthesis management. Furthermore, the simplicity of its design aims to reduce the cognitive load associated with editing Lisp code, freeing the developer to focus on the logic and algorithms of their programs rather than the syntactical overhead.
Summary of Comments ( 9 )
https://news.ycombinator.com/item?id=42766205
HN users generally praised Parinfer for making Lisp editing easier, especially for beginners. Several commenters shared positive experiences using it with Clojure, noting improvements in code readability and reduced parenthesis-related errors. Some highlighted its ability to infer parentheses placement based on indentation, simplifying structural editing. A few users discussed its potential applicability to other languages, and at least one pointed out its integration with popular editors. However, some expressed skepticism about its long-term benefits or preference for traditional Lisp editing approaches. A minor point of discussion revolved around the tool's name and how it relates to its functionality.
The Hacker News post "Parinfer: Simpler Lisp Editing" generated a moderate discussion with several commenters sharing their experiences and perspectives on Parinfer and Lisp editing in general.
Several users praised Parinfer for its innovative approach to structural editing, finding it significantly easier and less error-prone than traditional parenthesis management in Lisp. One commenter stated that it transformed their Clojure editing experience, eliminating the constant struggle with parentheses and allowing them to focus on the code's logic. Another shared that Parinfer made them enjoy writing Lisp again after previous frustrations. The intuitive nature of Parinfer's paren-handling and its ability to infer correct structure was highlighted as a key advantage.
Some users compared Parinfer favorably to other structural editing tools and techniques, such as Paredit. While acknowledging Paredit's power, they found Parinfer's approach simpler to learn and use, leading to a more fluid coding experience. One comment specifically mentioned the reduced cognitive load when using Parinfer compared to Paredit. However, other users expressed a preference for Paredit, arguing that its explicit commands offered more control and predictability. This sparked a brief discussion on the merits of different approaches to structural editing.
A few commenters raised potential drawbacks of Parinfer. One concern was the learning curve associated with a new editing paradigm, although some argued that this was minimal compared to the benefits. Another commenter mentioned the possibility of unexpected behavior in certain edge cases, suggesting that understanding the underlying rules of Parinfer is important for effective use. A desire for better editor integration and more comprehensive documentation was also expressed.
The discussion also touched upon broader topics related to Lisp and code editing. One comment highlighted the historical challenges of Lisp editing and how tools like Parinfer address these issues. Another discussed the importance of proper tooling for enhancing developer productivity and enjoyment. A commenter also mentioned the relevance of Parinfer's approach to other languages with significant syntactic structure, suggesting potential applications beyond Lisp.
Overall, the comments reflect a generally positive reception of Parinfer, with many users appreciating its simplified approach to Lisp editing. While some concerns and alternative viewpoints were presented, the overall sentiment suggests that Parinfer offers a compelling solution to a longstanding challenge in Lisp programming.