Stories with Tag Elisp

• Emacs Lisp Elements

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  Posted: 2025-04-12 15:09:14

  Verbose tl;dr

  This post provides a brief introduction to fundamental Emacs Lisp concepts. It covers basic data types like numbers, strings, and booleans, explaining how to manipulate them with built-in functions. The post also introduces lists, a crucial data structure in Lisp, showcasing their use in function definitions and data representation. It delves into defining functions with defun, demonstrating argument handling and return values. Finally, the post touches upon special forms like if and let for control flow and variable scoping, ultimately aiming to equip readers with the foundational knowledge needed to understand and write simple Emacs Lisp code.

  The article "Emacs Lisp Elements" by Protesilaos Stavrou provides a comprehensive, yet approachable, introduction to the fundamental concepts of Emacs Lisp, the programming language that powers the extensibility of the Emacs text editor. It aims to equip readers with a foundational understanding, enabling them to comprehend and modify existing Emacs Lisp code, as well as write their own customizations and extensions.

  The article begins by emphasizing the dynamic nature of Emacs Lisp and its tight integration with the Emacs environment. It highlights the interactive nature of the language, allowing users to evaluate and experiment with code directly within the editor. This empowers users to explore and learn Emacs Lisp organically, adapting the editor to their specific needs.

  The core elements of Emacs Lisp are then systematically presented. The article delves into the syntax of the language, explaining the significance of parentheses and prefix notation. It meticulously describes the different data types available, such as numbers, strings, symbols, lists, and booleans, providing clear examples of their usage.

  A significant portion of the article is dedicated to explaining functions, the building blocks of Emacs Lisp programs. The article details how to define functions using defun, how to call them, and how they operate on arguments. It also introduces the concept of lambda expressions for creating anonymous functions. The explanation of functions is complemented by a discussion of variables, outlining how to define and assign values to them using let and setq.

  Control flow mechanisms, essential for directing the execution of programs, are also addressed. The article elucidates conditional expressions using if, cond, and when, and discusses looping constructs like while and dolist. These explanations provide the reader with the tools to create more complex and dynamic Emacs Lisp code.

  Furthermore, the article explores the interaction of Emacs Lisp with the Emacs editor itself. It introduces the concept of buffers, windows, and keybindings, demonstrating how Emacs Lisp can manipulate these core components of the editing environment. It explains how to access and modify buffer content, manage windows, and define custom keybindings to execute specific Lisp functions, thereby demonstrating the practical application of Emacs Lisp for customizing the editor.

  The article concludes by emphasizing the practical benefits of learning Emacs Lisp, highlighting its power to personalize and extend the Emacs experience. It encourages readers to explore further and experiment with the language, offering guidance on where to find additional resources and documentation. The overarching aim is to empower users to take control of their editing environment and tailor it precisely to their workflow and preferences.

  • Emacs
  • Emacs Lisp
  • Elisp
  • Lisp
  • programming
  • Text Editor
  • Customization
  • Extending Emacs
  • Emacs Configuration
  • Tutorial
  • documentation

  Summary of Comments ( 43 )
  https://news.ycombinator.com/item?id=43665046

  Verbose tl;dr

  HN users largely praised the article for its clarity and accessibility in explaining Emacs Lisp fundamentals. Several commenters highlighted its usefulness for beginners, with one calling it the best introduction they'd seen. Some appreciated the focus on practical examples and the author's clear writing style. A few pointed out minor typos or suggested additional topics, like dynamic scoping. One user mentioned using the article as a basis for an Emacs Lisp presentation, further demonstrating its perceived value within the community. The overall sentiment was overwhelmingly positive, indicating the article successfully fills a need for a concise and understandable guide to Emacs Lisp.

  The Hacker News post titled "Emacs Lisp Elements" has generated a modest number of comments, primarily focusing on the accessibility and usefulness of the linked article as an introductory resource to Emacs Lisp.

  Several commenters praise the article for its clear and concise explanations, particularly appreciating its focus on fundamental concepts and avoidance of overly complex examples. One user specifically highlights the value of the article for beginners, stating that it provides a solid foundation for understanding Emacs Lisp without overwhelming the reader. Another commenter echoes this sentiment, emphasizing the article's helpfulness in grasping the basic building blocks of the language.

  The discussion also touches upon the broader context of learning Emacs and its customization capabilities. One commenter suggests that the article serves as a good starting point for users who want to delve deeper into Emacs Lisp and personalize their Emacs experience. Another points out the potential of Emacs Lisp for extending Emacs functionality and creating custom tools, further emphasizing the practical applications of the knowledge gained from the article.

  One user questions the necessity of learning Emacs Lisp for basic Emacs usage, suggesting that many users can effectively utilize Emacs without in-depth knowledge of the language. This prompts a counter-argument from another commenter who highlights the benefits of understanding Emacs Lisp, even at a basic level, for tasks such as customizing keybindings and minor configurations. This exchange reflects a common debate within the Emacs community regarding the balance between ease of use and the power of customization offered by Emacs Lisp.

  While several commenters appreciate the article's focus on simplicity, one user expresses a desire for more advanced topics and examples. This suggests that while the article caters well to beginners, it may not fully satisfy users seeking more in-depth exploration of Emacs Lisp capabilities.

  Overall, the comments generally portray the linked article as a valuable resource for individuals new to Emacs Lisp, offering a clear and accessible introduction to the language's fundamental concepts. While some users desire more advanced content, the majority of the comments focus on the article's effectiveness in providing a solid foundation for beginners.

• Emacs Tree-sitter custom highlighting

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  Posted: 2025-03-01 08:17:29

  Verbose tl;dr

  This blog post details how to implement custom syntax highlighting in Emacs using tree-sitter. The author demonstrates creating a minor mode for highlighting TODO items and FIXMEs in comments within C++ code. This involves defining specific queries that target the comment nodes in the tree-sitter parse tree and then associating faces (colors and styles) with the captured nodes. The example provides a practical illustration of leveraging tree-sitter's structured code understanding to achieve more precise and context-aware highlighting than traditional regular expression-based approaches. The post also briefly covers how to incorporate these queries into a theme for broader application and includes a troubleshooting tip for ensuring tree-sitter highlighting is active.

  Amit Patel's blog post, "Emacs Tree-sitter Custom Highlighting," explores leveraging the power of tree-sitter, a parsing library, for granular and context-aware syntax highlighting within Emacs. He begins by highlighting the limitations of traditional regular expression-based highlighting, noting its struggles with complex language constructs and the potential for slowdowns due to backtracking. Tree-sitter, in contrast, parses the code into an abstract syntax tree, allowing for more precise and efficient highlighting based on the actual structure of the code.

  Patel meticulously details the process of setting up tree-sitter in Emacs, including the installation of necessary packages and configuration steps. He then delves into the core of the post: customizing highlighting rules. He explains how to define custom "queries" using tree-sitter's query language. These queries effectively target specific nodes in the parsed syntax tree, enabling the application of distinct highlighting styles. He provides concrete examples demonstrating how to highlight function calls, variable declarations, and even specific keywords within different contexts.

  He emphasizes the flexibility and expressiveness of tree-sitter queries, showcasing how they can match patterns based not just on node types but also on their relationships within the tree, enabling highly specific highlighting scenarios. He illustrates this with an example of highlighting the self parameter in Python methods. Patel also covers handling language-specific configurations and ensuring smooth integration with existing Emacs themes.

  Furthermore, Patel explores more advanced usage, such as highlighting based on capture groups within queries and dynamically updating the highlighting as the code is modified. He acknowledges the initial complexity of learning the tree-sitter query language but argues that its power and precision justify the effort. He concludes by expressing his enthusiasm for the potential of tree-sitter to significantly enhance the code editing experience in Emacs. He encourages readers to explore the possibilities and contribute to the growing ecosystem of tree-sitter grammars and highlighting configurations.

  • Emacs
  • Tree-sitter
  • Syntax Highlighting
  • Customization
  • Elisp
  • Text Editor
  • Code Editor
  • parsing
  • programming
  • Software Development

  Summary of Comments ( 0 )
  https://news.ycombinator.com/item?id=43217195

  Verbose tl;dr

  HN commenters largely praised the integration of tree-sitter into Emacs, highlighting the significant improvements in syntax highlighting accuracy and performance. Some expressed excitement over the potential for more advanced features like semantic highlighting and code navigation enabled by tree-sitter's deeper understanding of code structure. A few users shared their personal experiences with setting up and using tree-sitter in Emacs, offering tips and workarounds for common issues. One commenter noted the wider adoption of tree-sitter across various editors and its positive impact on the developer experience. Others discussed the technical details of tree-sitter's implementation, comparing it to traditional regular expression-based highlighting. A couple of comments touched on the potential for future improvements, such as asynchronous parsing and better support for more obscure languages.

  The Hacker News post "Emacs Tree-sitter custom highlighting" discussing Amit Patel's blog post about the same topic has generated several comments. Many users express excitement and appreciation for the advancements in syntax highlighting offered by tree-sitter integration within Emacs.

  Several commenters discuss the performance improvements and accuracy of tree-sitter parsing compared to traditional regular expression-based highlighting. One user points out that tree-sitter is particularly beneficial for languages with complex grammars, where regex-based highlighting often struggles. They specifically mention JavaScript as an example.

  Another commenter praises the ability to highlight based on semantic understanding, enabling features like highlighting all variables of a specific type within a scope. This is highlighted as a significant improvement over purely syntactic highlighting.

  Some discussion revolves around the installation and configuration of tree-sitter in Emacs. One user asks for clarification on the setup process, and another provides helpful links and tips for getting started.

  A few comments mention other text editors and IDEs that have already adopted tree-sitter, highlighting its growing popularity and effectiveness. One user mentions its use in Neovim, and another points to its origins within Atom.

  The overall sentiment in the comments is positive, with many users excited about the potential of tree-sitter to enhance the Emacs editing experience. Several express their intent to try out the new features and contribute to its development. The improvements to accuracy, performance, and the ability for semantic highlighting are repeatedly lauded.