This paper introduces Deputy, a dependently typed language designed for practical programming. Deputy integrates dependent types into a Lisp-like language, aiming to balance the power of dependent types with the flexibility and practicality of dynamic languages. It achieves this through a novel combination of features: gradual typing, allowing seamless mixing of typed and untyped code; a hybrid type checker employing both static and dynamic checks; and a focus on intensional type equality, allowing for type-level computation and manipulation. This approach makes dependent types more accessible for everyday tasks by allowing programmers to incrementally add type annotations and leverage dynamic checking when full static verification is impractical or undesirable, ultimately bridging the gap between the theoretical power of dependent types and their use in real-world software development.
ClawPDF is an open-source, cross-platform virtual PDF printer that offers more than just basic PDF creation. It supports OCR, allowing users to create searchable PDFs from scanned documents or images. It also functions as a network printer, enabling PDF creation from any device on the network. Furthermore, ClawPDF boasts image conversion capabilities, allowing users to convert various image formats to PDF. Built with Python and utilizing Ghostscript, it aims to provide a flexible and feature-rich PDF printing solution.
HN commenters generally praise ClawPDF's feature set, particularly its OCR capabilities and open-source nature. Some express interest in self-hosting and appreciate the straightforward setup process. A few users raise concerns about potential security implications of running an open-source PDF printer, suggesting caution with sensitive documents. Others compare it favorably to existing solutions, noting its potential as a cost-effective alternative to commercial offerings. Several commenters also discuss desired features, like duplex scanning and improved OCR accuracy, and offer suggestions for enhancing the project, including Dockerization and integration with cloud storage services.
Extracting text from PDFs is surprisingly complex due to the format's focus on visual representation rather than logical structure. PDFs essentially describe how a page should look, specifying the precise placement of glyphs (often without even identifying them as characters) rather than encoding the underlying text itself. This can lead to difficulties in reconstructing the original text flow, especially with complex layouts involving columns, tables, and figures. Further complications arise from embedded fonts, ligatures, and the potential for text to be represented as paths or images, making accurate and reliable text extraction a significant technical challenge.
HN users discuss the complexities of accurate PDF-to-text conversion, highlighting issues stemming from PDF's original design as a visual format, not a semantic one. Several commenters point out the challenges posed by embedded fonts, tables, and the variety of PDF generation methods. Some suggest OCR as a necessary, albeit imperfect, solution for visually-oriented PDFs, while others mention tools like pdftotext and Apache PDFBox. The discussion also touches on the limitations of existing libraries and the ongoing need for robust solutions, particularly for complex or poorly generated PDFs. One compelling comment chain dives into the history of PDF and PostScript, explaining how the format's focus on visual fidelity complicates text extraction. Another insightful thread explores the different approaches taken by various PDF-to-text tools, comparing their strengths and weaknesses.
Philip Wadler's "Propositions as Types" provides a concise overview of the Curry-Howard correspondence, which reveals a deep connection between logic and programming. It explains how logical propositions can be viewed as types in a programming language, and how proofs of those propositions correspond to programs of those types. Specifically, implication corresponds to function types, conjunction to product types, disjunction to sum types, universal quantification to dependent product types, and existential quantification to dependent sum types. This correspondence allows programmers to reason about programs using logical tools, and conversely, allows logicians to use computational tools to reason about proofs. The paper illustrates these connections with clear examples, demonstrating how a proof of a logical formula can be directly translated into a program, and vice-versa, solidifying the idea that proofs are programs and propositions are the types they inhabit.
Hacker News users discuss Wadler's "Propositions as Types," mostly praising its clarity and accessibility in explaining the Curry-Howard correspondence. Several commenters share personal anecdotes about how the paper illuminated the connection between logic and programming for them, highlighting its effectiveness as an introductory text. Some discuss the broader implications of the correspondence and its relevance to type theory, automated theorem proving, and functional programming. A few mention related resources, like Software Foundations, and alternative presentations of the concept. One commenter notes the paper's omission of linear logic, while another suggests its focus is intentionally narrow for pedagogical purposes.
Wendell Berry argues against buying a computer in 1987, believing it offers no improvement to his writing process and presents several societal downsides. He emphasizes the value of his physical tools and the importance of resisting consumerism. He sees the computer as an unnecessary expense, especially given its potential to become obsolete quickly. He further criticizes the environmental impact of computer manufacturing and fears computers will contribute to job displacement, corporate centralization, and the erosion of community life. Ultimately, he values human connection and careful consideration over technological advancement and efficiency.
HN commenters largely agree with Wendell Berry's skepticism of computers, particularly his concerns about their societal impact. Several highlight the prescience of his observations about the potential for computers to centralize power, erode community, and create dependence. Some find his outright rejection of computers too extreme, suggesting a more nuanced approach is possible. Others discuss the irony of reading his essay online, while appreciating his call for careful consideration of technology's consequences. A few point out that Berry's agrarian lifestyle allows him a perspective unavailable to most. The top comment notes the essay is less a critique of computers themselves, and more a critique of the structures and systems they empower.
BreezePDF is a free, web-based PDF editor that runs entirely in your browser. It offers a range of functionalities, including text editing, image manipulation, adding annotations, filling forms, signing documents, and merging or splitting PDFs. No uploads or downloads are required, ensuring privacy as your files are processed locally. The tool aims to be a lightweight and user-friendly alternative to traditional desktop PDF software.
Hacker News users generally praised the simplicity and speed of BreezePDF, particularly its quick loading time compared to other online PDF editors. Some expressed concerns about privacy since the processing happens server-side, wishing for a client-side or self-hosted option. A few commenters mentioned existing open-source alternatives, suggesting BreezePDF could benefit from open-sourcing its own code. Others offered specific feature requests like OCR and digital signature support. The in-browser functionality was appreciated, but some questioned the long-term viability of the free model.
The 2025 SIGBOVIK conference proceedings showcase a collection of humorous and technically creative papers exploring unconventional and often absurd aspects of computer science. Topics range from generating Shakespearean insults with machine learning to developing a self-destructing paper airplane protocol, and analyzing the computational complexity of stacking chairs. The papers, presented with a veneer of academic rigor, embrace playful exploration of impractical ideas, highlighting the lighter side of research and the joy of creative problem-solving. While the research itself is not meant to be taken seriously, the underlying technical skills and cleverness demonstrated throughout the proceedings are genuinely impressive.
HN users generally expressed amusement and appreciation for the SIGBOVIK conference and its tradition of humorous, yet technically interesting, papers. Several commenters highlighted specific papers that caught their attention, including one about generating cooking recipes from code and another exploring the potential of AI-generated sea shanties. The absurdity of a paper analyzing the "metadata" of cave paintings also drew positive remarks. Some users reflected on the conference's history and the consistent quality of its satirical contributions to computer science. There was also a brief discussion about the challenges of discerning genuine AI-generated text from human-written parody.
Morphik is an open-source Retrieval Augmented Generation (RAG) engine designed for local execution. It differentiates itself by incorporating optical character recognition (OCR), enabling it to understand and process information contained within PDF images, not just text-based PDFs. This allows users to build knowledge bases from scanned documents and image-heavy files, querying them semantically via a natural language interface. Morphik offers a streamlined setup process and prioritizes data privacy by keeping all information local.
HN users generally expressed interest in Morphik, praising its local operation and potential for privacy. Some questioned the licensing (AGPLv3) and its suitability for commercial applications. Several commenters discussed the challenges of accurate OCR, particularly with complex or unusual PDFs, and hoped for future improvements in this area. Others compared it to existing tools, with some suggesting integration with tools like LlamaIndex. There was significant interest in its ability to handle images within PDFs, a feature lacking in many other RAG solutions. A few users pointed out potential use cases, such as academic research and legal document analysis. Overall, the reception was positive, with many eager to experiment with Morphik and contribute to its development.
This presentation provides a deep dive into advanced Bash scripting techniques. It covers crucial topics like regular expressions for pattern matching, utilizing built-in commands for string manipulation and file processing, and leveraging external utilities like sed and awk for more complex operations. The guide emphasizes practical scripting skills, demonstrating how to control program flow with loops and conditional statements, handle signals and traps for robust script behavior, and effectively manage variables and functions for modular and reusable code. It also delves into input/output redirection, process management, and here documents, equipping users to write powerful and efficient shell scripts for automating various system administration tasks.
HN commenters generally praise the linked Bash scripting guide for its clarity and comprehensiveness, especially regarding lesser-known features and best practices. Several highlight the sections on quoting and variable expansion as particularly valuable for avoiding common pitfalls. Some suggest the guide, while older, remains relevant for intermediate/advanced users looking to solidify their understanding. A few users mention alternative resources or offer minor critiques, such as the guide's lack of coverage on newer Bash features or the density of information, but the overall sentiment is positive, viewing the PDF as a valuable resource for improving Bash scripting skills. The mention of set -u (nounset) to catch undefined variables is brought up multiple times as a crucial takeaway.
The 1926 Ames Shovel and Tool catalog showcases a comprehensive range of shovels, spades, scoops, and related tools for various applications. It details numerous variations in blade shape, size, and handle material (wood or steel) tailored for specific tasks like digging, scooping, and moving different materials such as coal, grain, and snow. The catalog emphasizes the quality of Ames's forged steel construction, highlighting features like reinforced sockets and hardened blades for durability. It also includes information on specialized tools like post-hole diggers, drain spades, and asphalt shovels, showcasing the breadth of Ames's product line for both professional and consumer use.
HN commenters were fascinated by the 1926 Ames shovel catalog, expressing surprise at the sheer variety of shovels available for specialized tasks. Several noted the detailed specifications and illustrations, appreciating the craftsmanship and attention to detail evident in a pre-mass-production era. Some discussed the historical context, including the likely use of prison labor in manufacturing and the evolution of shovel design. Others pointed out the catalog's value for researchers, historians, and those interested in industrial design or material culture. A few users reminisced about using similar tools, highlighting the enduring utility of basic hand tools. The high quality and specialized nature of these tools prompted reflection on modern manufacturing and the decline of specialized craftsmanship.
KOReader is a free and open-source document viewer focused on e-ink devices like Kobo, Kindle, PocketBook, and Android. It emphasizes comfortable reading, offering features like customizable fonts, margins, and line spacing, along with extensive dictionary integration, footnote support, and various text-to-speech options. KOReader supports a wide range of document formats, including PDF, EPUB, MOBI, DjVu, CBZ, and CBR. The project aims to provide a flexible and feature-rich reading experience tailored to the unique demands of e-ink displays.
HN users praise KOReader for its customizability, speed, and support for a wide range of document formats. Several commenters highlight its excellent PDF handling, especially for scientific papers and technical documents, contrasting it favorably with other readers. Some appreciate its minimalist UI and focus on reading, while others discuss advanced features like dictionaries and syncing. The ability to run on older and less powerful hardware is also mentioned as a plus. A few users mention minor issues or desired features, like improved EPUB reflow, but overall the sentiment is very positive, with many long-time users chiming in to recommend it. One commenter notes its particular usefulness for reading academic papers and textbooks, praising its ability to handle complex layouts and annotations.
Ursula K. Le Guin's "The Child and the Shadow" explores the crucial role of integrating the shadow self for healthy psychological development. Le Guin uses the fairy tale of "The Shadow" by Hans Christian Andersen to illustrate how denying or repressing the shadow leads to alienation and unhappiness. She argues that the shadow, representing our darker impulses and less admirable qualities, must be acknowledged and accepted as part of the whole self. Through consciousness and acceptance, the shadow can be integrated, leading to wholeness, maturity, and the ability to connect authentically with others. This process, though potentially frightening, is essential for living a full and meaningful life.
HN users discuss Le Guin's essay on the shadow self, largely agreeing with her premise of integrating rather than suppressing the negative aspects of personality. Several commenters appreciate the Jungian perspective and explore the idea of the shadow as a source of creativity and authenticity. Some discuss the practical challenges of integrating the shadow, noting the societal pressures to conform and the difficulty in accepting uncomfortable truths about oneself. The danger of projecting the shadow onto others is also highlighted, as is the importance of self-awareness in navigating these complexities. A few commenters mention the relevance of Le Guin's essay to current societal issues, such as political polarization. Overall, the comments reflect a thoughtful engagement with Le Guin's ideas.
Mads Tofte's "Four Lectures on Standard ML" provides a concise introduction to the core concepts of SML. It covers the fundamental aspects of the language, including its type system with polymorphism and type inference, its support for functional programming with higher-order functions, and its module system for structuring large programs. The lectures emphasize clarity and practicality, demonstrating how these features contribute to writing reliable and reusable code. Examples illustrate key concepts like pattern matching, data structures, and abstract data types. The text aims to provide a solid foundation for further exploration of SML and its applications.
Hacker News users discuss Mads Tofte's "Four Lectures on Standard ML" with appreciation for its clarity and historical context. Several commenters highlight the document as an excellent introduction to ML and type inference, praising its conciseness and accessibility compared to more modern resources. Some note the significance of seeing the language presented shortly after its creation, offering a glimpse into its original design principles. The lack of dependent types is mentioned, with one commenter pointing out that adding them would significantly alter ML's straightforward type inference. Others discuss the influence of ML on later languages like Haskell and OCaml, and the enduring relevance of its core concepts. A few users reminisce about their experiences learning ML and using related tools like SML/NJ.
Paged Out #6 explores the growing complexity in software, focusing on the challenges of debugging. It argues that traditional debugging methods are becoming inadequate for modern systems, which often involve distributed architectures, asynchronous operations, and numerous interacting components. The zine dives into various advanced debugging techniques like reverse debugging, using eBPF for observability, and applying chaos engineering principles to uncover vulnerabilities. It highlights the importance of understanding system behavior as a whole, rather than just individual components, advocating for tools and approaches that provide a more holistic view of execution flow and state. Finally, it touches on the psychological aspects of debugging, emphasizing the need for patience, persistence, and a structured approach to problem-solving in complex environments.
HN users generally praised the issue of Paged Out, finding the articles well-written and insightful. Several commenters highlighted specific pieces, such as the one on "The Spectre of Infinite Retry" and another discussing the challenges of building a database on top of a distributed consensus system. The article on the Unix philosophy also generated positive feedback. Some users appreciated the magazine's focus on systems programming and lower-level topics. There was some light discussion of the practicality of formal methods in software development, prompted by one of the articles. Overall, the reception was very positive with many expressing anticipation for future issues.
This report presents compact models for advanced transistors like FinFETs and gate-all-around (GAA) devices, focusing on improving accuracy and physical interpretability while maintaining computational efficiency. It explores incorporating non-quasi-static effects, crucial for high-frequency operation, into the surface-potential-based models. The work details advanced methods for modeling short-channel effects, temperature dependence, and variability, leading to more predictive simulations. Ultimately, the report provides a framework for developing compact models suitable for circuit design and analysis of modern integrated circuits with these complex transistor structures.
HN users discuss the challenges of creating compact models for advanced transistors, highlighting the increasing complexity and the difficulty of balancing accuracy, computational cost, and physical interpretability. Some commenters note the shift towards machine learning-based models as a potential solution, albeit with concerns about their "black box" nature and lack of physical insight. Others emphasize the enduring need for physics-based models, especially for understanding device behavior and circuit design. The limitations of current industry-standard models like BSIM are also acknowledged, alongside the difficulty of validating models against real-world silicon behavior. Several users appreciate the shared resource and express interest in the historical context of model development.
Francis Bach's "Learning Theory from First Principles" provides a comprehensive and self-contained introduction to statistical learning theory. The book builds a foundational understanding of the core concepts, starting with basic probability and statistics, and progressively developing the theory behind supervised learning, including linear models, kernel methods, and neural networks. It emphasizes a functional analysis perspective, using tools like reproducing kernel Hilbert spaces and concentration inequalities to rigorously analyze generalization performance and derive bounds on the prediction error. The book also covers topics like stochastic gradient descent, sparsity, and online learning, offering both theoretical insights and practical considerations for algorithm design and implementation.
HN commenters generally praise the book "Learning Theory from First Principles" for its clarity, rigor, and accessibility. Several appreciate its focus on fundamental concepts and building a solid theoretical foundation, contrasting it favorably with more applied machine learning resources. Some highlight the book's coverage of specific topics like Rademacher complexity and PAC-Bayes. A few mention using the book for self-study or teaching, finding it well-structured and engaging. One commenter points out the authors' inclusion of online exercises and solutions, further enhancing its educational value. Another notes the book's free availability as a significant benefit. Overall, the sentiment is strongly positive, recommending the book for anyone seeking a deeper understanding of learning theory.
The seL4 microkernel is a highly secure and reliable operating system foundation, formally verified to guarantee functional correctness and security properties. This verification proves that the implementation adheres to its specification, encompassing properties like data integrity and control-flow integrity. Designed for high-performance and real-time embedded systems, seL4's small size and minimal interface facilitate formal analysis and predictable resource usage. Its strong isolation mechanisms enable the construction of robust systems where different components with varying levels of trust can coexist securely, preventing failures in one component from affecting others. The kernel's open-source nature and liberal licensing promote transparency and wider adoption, fostering further research and development in secure systems.
Hacker News users discussed the seL4 microkernel, focusing on its formal verification and practical applications. Some questioned the real-world impact of the verification, highlighting the potential for vulnerabilities outside the kernel's scope, such as in device drivers or user-space applications. Others praised the project's rigor and considered it a significant achievement in system software. Several comments mentioned the challenges of using microkernels effectively, including the performance overhead of inter-process communication (IPC). Some users also pointed out the limited adoption of microkernels in general, despite their theoretical advantages. There was also interest in seL4's use in specific applications like autonomous vehicles and aerospace.
This 1986 paper explores representing the complex British Nationality Act 1981 as a Prolog program. It demonstrates how Prolog's declarative nature and built-in inference mechanisms can effectively encode the Act's intricate rules regarding citizenship acquisition and loss. The authors translate legal definitions of British citizenship, descent, and residency into Prolog clauses, showcasing the potential of logic programming to represent and reason with legal statutes. While acknowledging the limitations of this initial attempt, such as simplifying certain aspects of the Act and handling time-dependent clauses, the paper highlights the potential of using Prolog for legal expert systems and automated legal reasoning. It ultimately serves as an early exploration of applying computational logic to the domain of law.
Hacker News users discussed the ingenuity of representing the British Nationality Act as a Prolog program, highlighting the elegance of Prolog for handling complex logic and legal rules. Some expressed nostalgia for the era's focus on symbolic AI and rule-based systems. Others debated the practicality and maintainability of such an approach for real-world legal applications, citing the potential difficulty of updating and debugging the code as laws change. The discussion also touched on the broader implications of encoding law in a computationally interpretable format, considering the benefits for automated legal reasoning and the potential risks of bias and misinterpretation. Some users shared their own experiences with Prolog and other logic programming languages, and pondered the reasons for their decline in popularity despite their inherent strengths for certain problem domains.
Dwayne Phillips' "Image Processing in C" offers a practical, code-driven introduction to image manipulation techniques. The book focuses on foundational concepts and algorithms, providing C code examples for tasks like reading and writing various image formats, performing histogram equalization, implementing spatial filtering (smoothing and sharpening), edge detection, and dithering. It prioritizes clarity and simplicity over complex mathematical derivations, making it accessible to programmers seeking a hands-on approach to learning image processing basics. While the book uses older image formats and C libraries, the core principles and algorithms remain relevant for understanding fundamental image processing operations.
Hacker News users discussing Dwayne Phillips' "Image Processing in C" generally praise its clarity and practicality, especially for beginners. Several commenters highlight its focus on fundamental concepts and algorithms, making it a good foundational resource even if the C code itself is dated. Some suggest pairing it with more modern libraries like OpenCV for practical application. A few users point out its limitations, such as the lack of coverage on more advanced topics, while others appreciate its conciseness and accessibility compared to denser academic texts. The code examples are praised for their simplicity and illustrative nature, promoting understanding over optimized performance.
DeepMind's Gemma 3 report details the development and capabilities of their third-generation language model. It boasts improved performance across a variety of tasks compared to previous versions, including code generation, mathematics, and general knowledge question answering. The report emphasizes the model's strong reasoning abilities and highlights its proficiency in few-shot learning, meaning it can effectively generalize from limited examples. Safety and ethical considerations are also addressed, with discussions of mitigations implemented to reduce harmful outputs like bias and toxicity. Gemma 3 is presented as a versatile model suitable for research and various applications, with different sized versions available to balance performance and computational requirements.
Hacker News users discussing the Gemma 3 technical report express cautious optimism about the model's capabilities while highlighting several concerns. Some praised the report's transparency regarding limitations and biases, contrasting it favorably with other large language model releases. Others questioned the practical utility of Gemma given its smaller size compared to leading models, and the lack of clarity around its intended use cases. Several commenters pointed out the significant compute resources still required for training and inference, raising questions about accessibility and environmental impact. Finally, discussions touched upon the ongoing debates surrounding open-sourcing LLMs, safety implications, and the potential for misuse.
This 1989 Xerox PARC paper argues that Unix, despite its strengths, suffers from a fragmented environment hindering programmer productivity. It lacks a unifying framework integrating tools and information, forcing developers to grapple with disparate interfaces and manually manage dependencies. The paper proposes an integrated environment, similar to Smalltalk or Interlisp, built upon a shared repository and incorporating features like browsing, version control, configuration management, and debugging within a consistent user interface. This would streamline the software development process by automating tedious tasks, improving code reuse, and fostering better communication among developers. The authors advocate for moving beyond the Unix philosophy of small, independent tools towards a more cohesive and interactive system that supports the entire software lifecycle.
Hacker News users discussing the Xerox PARC paper lament the lack of a truly integrated computing environment, even decades later. Several commenters highlight the continued relevance of the paper's criticisms of Unix's fragmented toolset and the persistent challenges in achieving seamless interoperability. Some point to Smalltalk as an example of a more integrated system, while others mention Lisp Machines and Oberon. The discussion also touches upon the trade-offs between integration and modularity, with some arguing that Unix's modularity, while contributing to its fragmentation, is also a key strength. Others note the influence of the internet and the web, suggesting that these technologies shifted the focus away from tightly integrated desktop environments. There's a general sense of nostalgia for the vision presented in the paper and a recognition of the ongoing struggle to achieve a truly unified computing experience.
This 1987 paper by Dybvig explores three distinct implementation models for Scheme: compilation to machine code, abstract machine interpretation, and direct interpretation of source code. It argues that while compilation offers the best performance for finished programs, the flexibility and debugging capabilities of interpreters are crucial for interactive development environments. The paper details the trade-offs between these models, emphasizing the advantages of a mixed approach that leverages both compilation and interpretation techniques. It concludes that an ideal Scheme system would utilize compilation for optimized execution and interpretation for interactive use, debugging, and dynamic code loading, hinting at a system where the boundaries between compiled and interpreted code are blurred.
HN commenters discuss the historical significance of the paper in establishing Scheme's minimalist design and portability. They highlight the cleverness of the three implementations, particularly the threaded code interpreter, and its influence on later languages like Lua. Some note the paper's accessibility and clarity, even for those unfamiliar with Scheme, while others reminisce about using the techniques described. A few comments delve into technical details like register allocation and garbage collection, comparing the approaches to modern techniques. The overall sentiment is one of appreciation for the paper's contribution to computer science and programming language design.
This article from the Journal of the Printing Historical Society details the history of phototypesetting at Monotype, focusing on their transition from hot metal to photographic composition. It covers the initial reluctance to embrace the new technology, driven by a significant investment in hot metal, and the eventual development of filmsetters like the Monophoto, Lasercomp, and Linotron 202. The piece highlights the technical challenges overcome, the evolution of font design and storage for photographic systems, and the ultimate impact of these innovations on the printing industry, marking a significant shift away from traditional methods.
Hacker News users discuss the linked PDF, which details the history of Monotype's involvement with phototypesetting. Several commenters express fascination with the technical details of early phototypesetting machines, particularly the challenges of achieving high-quality output and the ingenious mechanical solutions employed. Some lament the loss of the aesthetic qualities of hot metal type in the transition to phototypesetting, while others appreciate the increased speed and flexibility the newer technology offered. A few commenters share personal anecdotes about working with Monotype equipment, providing firsthand accounts of the era. The discussion also touches upon the broader historical context of the printing industry's shift from analog to digital processes.
Jürgen Schmidhuber's "Matters Computational" provides a comprehensive overview of computer science, spanning its theoretical foundations and practical applications. It delves into topics like algorithmic information theory, computability, complexity theory, and the history of computation, including discussions of Turing machines and the Church-Turing thesis. The book also explores the nature of intelligence and the possibilities of artificial intelligence, covering areas such as machine learning, neural networks, and evolutionary computation. It emphasizes the importance of self-referential systems and universal problem solvers, reflecting Schmidhuber's own research interests in artificial general intelligence. Ultimately, the book aims to provide a unifying perspective on computation, bridging the gap between theoretical computer science and the practical pursuit of artificial intelligence.
HN users discuss the density and breadth of "Matters Computational," praising its unique approach to connecting diverse computational topics. Several commenters highlight the book's treatment of randomness, floating-point arithmetic, and the FFT as particularly insightful. The author's background in physics is noted, contributing to the book's distinct perspective. Some find the book challenging, requiring multiple readings to fully grasp the concepts. The free availability of the PDF is appreciated, and its enduring relevance a decade after publication is also remarked upon. A few commenters express interest in a physical copy, while others suggest potential updates or expansions on certain topics.
Trellis is hiring engineers to build AI-powered tools specifically designed for working with PDFs. They aim to create the best AI agents for interacting with and manipulating PDF documents, streamlining tasks like data extraction, analysis, and form completion. The company is backed by Y Combinator and emphasizes a fast-paced, innovative environment.
HN commenters express skepticism about the feasibility of creating truly useful AI agents for PDFs, particularly given the varied and complex nature of PDF data. Some question the value proposition, suggesting existing tools and techniques already adequately address common PDF-related tasks. Others are concerned about potential hallucination issues and the difficulty of verifying AI-generated output derived from PDFs. However, some commenters express interest in the potential applications, particularly in niche areas like legal or financial document analysis, if accuracy and reliability can be assured. The discussion also touches on the technical challenges involved, including OCR limitations and the need for robust semantic understanding of document content. Several commenters mention alternative approaches, like vector databases, as potentially more suitable for this problem domain.
Donald Knuth's 1986 reflection on the IBM 650 celebrates its profound impact on his formative years as a programmer and computer scientist. He fondly details the machine's quirks, from its rotating magnetic drum memory and bi-quinary arithmetic to its unique assembly language, SOAP. Knuth emphasizes the 650's educational value, arguing that its limitations encouraged creative problem-solving and a deep understanding of computational processes. He contrasts this with the relative "black box" nature of later machines, lamenting the lost art of optimizing code for specific hardware characteristics. Ultimately, the essay is a tribute to the 650's role in fostering a generation of programmers who learned to think deeply about computation at a fundamental level.
HN commenters generally express appreciation for Knuth's historical perspective and the glimpse into early computing. Several share personal anecdotes of using the IBM 650, recalling its quirks like the rotating drum memory and the challenges of programming with SOAP (Symbolic Optimum Assembly Program). Some discuss the significant impact the 650 had despite its limitations, highlighting its role in educating a generation of programmers and paving the way for future advancements. One commenter points out the machine's influence on Knuth's later work, specifically The Art of Computer Programming. Others compare and contrast the 650 with other early computers and discuss the evolution of programming languages and techniques. A few commenters express interest in emulating the 650.
The author is seeking recommendations for a Markdown to PDF conversion tool that handles complex formatting well, specifically callouts (like admonitions), diagrams using Mermaid or PlantUML, and math using LaTeX or KaTeX. They require a command-line interface for automation and prefer open-source solutions or at least freely available ones for non-commercial use. Existing tools like Pandoc are falling short in areas like callout styling and consistent rendering across different environments. Ideally, the tool would offer a high degree of customizability and produce clean, visually appealing PDFs suitable for documentation.
The Hacker News comments discuss various Markdown to PDF conversion tools, focusing on the original poster's requirements of handling code blocks, math, and images well while being ideally open-source and CLI-based. Pandoc is overwhelmingly recommended as the most powerful and flexible option, though some users caution about its complexity. Several commenters suggest simpler alternatives like md-to-pdf, glow, and Typora for less demanding use cases. Some discussion revolves around specific features, like LaTeX integration for math rendering and the challenges of perfectly replicating web-based Markdown rendering in a PDF. A few users mention using custom scripts or web services, while others highlight the benefits of tools like Marked 2 for macOS. The overall consensus seems to be that while a perfect solution might not exist, Pandoc with custom templates or simpler dedicated tools can often meet specific needs.
OlmOCR is a free and open-source tool designed for extracting text from PDF documents, especially those with complex layouts or scanned images. It leverages LayoutLM, a powerful model for understanding both textual and visual elements within a document, to achieve high accuracy in text recognition and extraction. The tool prioritizes ease of use, providing a straightforward command-line interface and requiring minimal setup. It aims to be a robust and accessible solution for anyone needing to convert PDFs into editable and searchable text.
Hacker News users generally expressed enthusiasm for OlmOCR, praising its open-source nature and potential to improve upon existing PDF extraction tools. Some highlighted its impressive performance, particularly with scanned documents, and its ease of use via a command-line interface and Python library. A few commenters pointed out specific advantages like its handling of mathematical formulas and compared it favorably to other tools like Tesseract. Some discussion also centered on the challenges of OCR, particularly with complex layouts and the nuances of accurately extracting meaning from text. One commenter suggested potential integration with other tools and platforms to broaden its accessibility.
iText, a popular Java PDF library, is celebrating its 25th anniversary with the release of iText Suite 9.1. This release focuses on improved SVG and CSS support, enabling developers to more easily incorporate these web technologies into PDF documents. Performance enhancements, particularly for table rendering, are also a key feature of this update. Additionally, iText DITO, the low-code PDF template generator, now offers a JavaScript API and several other improvements. The post emphasizes iText's long history and commitment to providing powerful PDF manipulation tools for developers.
Hacker News users discussed iText's longevity and evolution. Some expressed frustration with its licensing changes over the years, transitioning from AGPL to a commercial model. Others praised its performance improvements, particularly with SVG and CSS handling in the latest version. Several commenters shared their experiences using iText, highlighting its utility for generating complex PDFs, while acknowledging the learning curve involved. The licensing changes prompted a discussion about open-source alternatives, with Apache PDFBox frequently mentioned. Some users also pointed out quirks and limitations they encountered, such as font handling and table creation complexities.
This 1996 document outlines the puzzle design for the adventure game Grim Fandango. It details the game's four-year structure, dividing the story into distinct acts and locations. Each act's puzzles are meticulously charted, specifying the required items, character interactions, and logical steps players must take. The document emphasizes a focus on logical, inventory-based puzzles that arise naturally from the narrative, aiming to avoid "moon logic" and ensure solutions feel fair and intuitive. It also tracks the player's inventory throughout the game, highlighting key items and their uses. This detailed planning aimed to create a tightly-woven and engaging player experience.
Hacker News users discussing the Grim Fandango puzzle document generally express appreciation for its insight into game design, particularly the iterative process and the challenges of balancing difficulty. Several commenters note the document's demonstration of how seemingly minor details can significantly impact puzzle solutions, highlighting the complexity of creating a cohesive and enjoyable player experience. The document's focus on avoiding "moon logic" and ensuring puzzles feel fair is also praised. Some commenters draw parallels to other adventure games, like Monkey Island, and discuss the evolution of puzzle design in the genre. A few users also reminisce about their personal experiences playing Grim Fandango, reinforcing its status as a classic.
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https://news.ycombinator.com/item?id=44041515
Hacker News users discuss the paper "The Lisp in the Cellar: Dependent Types That Live Upstairs," focusing on the practicality and implications of its approach to dependent types. Some express skepticism about the claimed performance benefits and question the trade-offs made for compile-time checking. Others praise the novelty of the approach, comparing it favorably to other dependently-typed languages like Idris and highlighting the potential for more efficient and reliable software. A key point of discussion revolves around the use of a "cellar" for runtime values and an "upstairs" for compile-time values, with users debating the elegance and effectiveness of this separation. There's also interest in the language's metaprogramming capabilities and its potential for broader adoption within the functional programming community. Several commenters express a desire to experiment with the language and see further development.
The Hacker News post titled "The Lisp in the Cellar: Dependent Types That Live Upstairs [pdf]" links to a PDF describing a programming language called Deputy. The discussion in the comments section is relatively brief, with a focus on the practicality and implications of the presented ideas.
One commenter expresses skepticism about the overall benefit of dependent types, questioning if the added complexity is worth the effort and if the advantages primarily apply to specific niches like formal verification. They seem to imply that for general-purpose programming, the trade-offs might not be favorable.
Another commenter points out a perceived similarity between Deputy's approach and the concept of gradual typing. They suggest that Deputy seems to be striving for a system where dependent types can be introduced incrementally, allowing developers to choose where and when to apply the stricter typing discipline.
A third comment delves into the technical details of Deputy's type system, highlighting its use of elaboration and normalization. They specifically mention that values are normalized during elaboration, comparing this approach to how Agda, another dependently typed language, handles type checking. They also raise a question about the implementation of large eliminations, a technical aspect related to how dependent types are handled in practice.
Finally, someone notes the irony in the paper's title, "The Lisp in the Cellar: Dependent Types That Live Upstairs," by pointing out that historically, Lisp has often been associated with more academic or advanced programming concepts, while dependent types are now being brought into that same realm. This comment focuses on the shifting perceptions and adoption of these programming paradigms.
While there are other comments, they are largely short expressions of interest, questions about specific technical details, or requests for clarification. The comments summarized above represent the most substantial points of discussion and offer insights into the community's reaction to the Deputy language and its features.