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<![CDATA[I upgraded my Raspberry Pi 400 to 64-bit Raspberry Pi OS 2024-11-19 based on Debian Bookworm 12.9: The desktop of 64-bit Raspberry Pi OS 2024-11-19 on a Raspberry Pi 400. Since I had no files to preserve the process was surprisingly easy as I went with a full installation. And this time I finally used the Raspberry Pi Imager. When I first set up the Pi 400 my only other desktop computer was a Chromebox that couldn't run the Imager on Crostini Linux. This imposed a less convenient network installation which, combined with a subtle bug, made me waste a couple of hours over three installation attempts. Now I have a real Linux PC that runs the Imager just fine. Downloading Raspberry Pi OS, configuring it, and flashing the microSD card went smoothly. When I booted the Pi 400 from the card I was greeted by a ready to run system. On the newly upgraded system, building Medley Interlisp from source for X11 took an hour or so. The environment still runs well with the labwc Wayland...
3 months ago

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More from Paolo Amoroso's Journal

My first year since coming back to Linux

<![CDATA[It has been a year since I set up my System76 Merkaat with Linux Mint. In July of 2024 I migrated from ChromeOS and the Merkaat has been my daily driver on the desktop. A year later I have nothing major to report, which is the point. Despite the occasional unplanned reinstallation I have been enjoying the stability of Linux and just using the PC. This stability finally enabled me to burn bridges with mainstream operating systems and fully embrace Linux and open systems. I'm ready to handle the worst and get back to work. Just a few years ago the frustration of troubleshooting a broken system would have made me seriously consider the switch to a proprietary solution. But a year of regular use, with an ordinary mix of quiet moments and glitches, gave me the confidence to stop worrying and learn to love Linux. linux a href="https://remark.as/p/journal.paoloamoroso.com/my-first-year-since-coming-back-to-linux"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>

4 days ago 11 votes
Adding graphics support to DandeGUI

<![CDATA[DandeGUI now does graphics and this is what it looks like. Some text and graphics output windows created with DandeGUI on Medley Interlisp. In addition to the square root table text output demo, I created the other graphics windows with the newly implemented functionality. For example, this code draws the random circles of the top window: (DEFUN RANDOM-CIRCLES (&KEY (N 200) (MAX-R 50) (WIDTH 640) (HEIGHT 480)) (LET ((RANGE-X (- WIDTH ( 2 MAX-R))) (RANGE-Y (- HEIGHT ( 2 MAX-R))) (SHADES (LIST IL:BLACKSHADE IL:GRAYSHADE (RANDOM 65536)))) (DANDEGUI:WITH-GRAPHICS-WINDOW (STREAM :TITLE "Random Circles") (DOTIMES (I N) (DECLARE (IGNORE I)) (IL:FILLCIRCLE (+ MAX-R (RANDOM RANGE-X)) (+ MAX-R (RANDOM RANGE-Y)) (RANDOM MAX-R) (ELT SHADES (RANDOM 3)) STREAM))))) GUI:WITH-GRAPHICS-WINDOW, GUI:OPEN-GRAPHICS-STREAM, and GUI:WITH-GRAPHICS-STREAM are the main additions. These functions and macros are the equivalent for graphics of what GUI:WITH-OUTPUT-TO-WINDOW, GUI:OPEN-WINDOW-STREAM, and GUI:WITH-WINDOW-STREAM, respectively, do for text. The difference is the text facilities send output to TEXTSTREAM streams whereas the graphics facilities to IMAGESTREAM, a type of device-independent graphics streams. Under the hood DandeGUI text windows are customized TEdit windows with an associated TEXTSTREAM. TEdit is the rich text editor of Medley Interlisp. Similarly, the graphics windows of DandeGUI run the Sketch line drawing editor under the hood. Sketch windows have an IMAGESTREAM which Interlisp graphics primitives like IL:DRAWLINE and IL:DRAWPOINT accept as an output destination. DandeGUI creates and manages Sketch windows with the type of stream the graphics primitives require. In other words, IMAGESTREAM is to Sketch what TEXTSTREAM is to TEdit. The benefits of programmatically using Sketch for graphics are the same as TEdit windows for text: automatic window repainting, scrolling, and resizing. The downside is overhead. Scrolling more than a few thousand graphics elements is slow and adding even more may crash the system. However, this is an acceptable tradeoff. The new graphics functions and macros work similarly to the text ones, with a few differences. First, DandeGUI now depends on the SKETCH and SKETCH-STREAM library modules which it automatically loads. Since Sketch has no notion of a read-only drawing area GUI:OPEN-GRAPHICS-STREAM achieves the same effect by other means: (DEFUN OPEN-GRAPHICS-STREAM (&KEY (TITLE "Untitled")) "Open a new window and return the associated IMAGESTREAM to send graphics output to. Sets the window title to TITLE if supplied." (LET ((STREAM (IL:OPENIMAGESTREAM '|Untitled| 'IL:SKETCH '(IL:FONTS ,DEFAULT-FONT*))) (WINDOW (IL:\\SKSTRM.WINDOW.FROM.STREAM STREAM))) (IL:WINDOWPROP WINDOW 'IL:TITLE TITLE) ;; Disable left and middle-click title bar menu (IL:WINDOWPROP WINDOW 'IL:BUTTONEVENTFN NIL) ;; Disable sketch editing via right-click actions (IL:WINDOWPROP WINDOW 'IL:RIGHTBUTTONFN NIL) ;; Disable querying the user whether to save changes (IL:WINDOWPROP WINDOW 'IL:DONTQUERYCHANGES T) STREAM)) Only the mouse gestures and commands of the middle-click title bar menu and the right-click menu change the drawing area interactively. To disable these actions GUI:OPEN-GRAPHICS-STREAM removes their menu handlers by setting to NIL the window properties IL:BUTTONEVENTFN and IL:RIGHTBUTTONFN. This way only programmatic output can change the drawing area. The function also sets IL:DONTQUERYCHANGES to T to prevent querying whether to save the changes at window close. By design output to DandeGUI windows is not permanent, so saving isn't necessary. GUI:WITH-GRAPHICS-STREAM and GUI:WITH-GRAPHICS-WINDOW are straightforward: (DEFMACRO WITH-GRAPHICS-STREAM ((VAR STREAM) &BODY BODY) "Perform the operations in BODY with VAR bound to the graphics window STREAM. Evaluates the forms in BODY in a context in which VAR is bound to STREAM which must already exist, then returns the value of the last form of BODY." `(LET ((,VAR ,STREAM)) ,@BODY)) (DEFMACRO WITH-GRAPHICS-WINDOW ((VAR &KEY TITLE) &BODY BODY) "Perform the operations in BODY with VAR bound to a new graphics window stream. Creates a new window titled TITLE if supplied, binds VAR to the IMAGESTREAM associated with the window, and executes BODY in this context. Returns the value of the last form of BODY." `(WITH-GRAPHICS-STREAM (,VAR (OPEN-GRAPHICS-STREAM :TITLE (OR ,TITLE "Untitled"))) ,@BODY)) Unlike GUI:WITH-TEXT-STREAM and GUI:WITH-TEXT-WINDOW, which need to call GUI::WITH-WRITE-ENABLED to establish a read-only environment after every output operation, GUI:OPEN-GRAPHICS-STREAM can do this only once at window creation. GUI:CLEAR-WINDOW, GUI:WINDOW-TITLE, and GUI:PRINT-MESSAGE now work with graphics streams in addition to text streams. For IMAGESTREAM arguments GUI:PRINT-MESSAGE prints to the system prompt window as Sketch stream windows have no prompt area. The random circles and fractal triangles graphics demos round up the latest additions. #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/adding-graphics-support-to-dandegui"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>

a month ago 19 votes
Changing text style for DandeGUI window output

<![CDATA[Printing rich text to windows is one of the planned features of DandeGUI, the GUI library for Medley Interlisp I'm developing in Common Lisp. I finally got around to this and implemented the GUI:WITH-TEXT-STYLE macro which controls the attributes of text printed to a window, such as the font family and face. GUI:WITH-TEXT-STYLE establishes a context in which text printed to the stream associated with a TEdit window is rendered in the style specified by the arguments. The call to GUI:WITH-TEXT-STYLE here extends the square root table example by printing the heading in a 12-point bold sans serif font: (gui:with-output-to-window (stream :title "Table of square roots") (gui:with-text-style (stream :family :sans :size 12 :face :bold) (format stream "~&Number~40TSquare Root~2%")) (loop for n from 1 to 30 do (format stream "~&~4D~40T~8,4F~%" n (sqrt n)))) The code produces this window in which the styled column headings stand out: Medley Interlisp window of a square root table generated by the DandeGUI GUI library. The :FAMILY, :SIZE, and :FACE arguments determine the corresponding text attributes. :FAMILY may be a generic family such as :SERIF for an unspecified serif font; :SANS for a sans serif font; :FIX for a fixed width font; or a keyword denoting a specific family like :TIMESROMAN. At the heart of GUI:WITH-TEXT-STYLE is a pair of calls to the Interlisp function PRINTOUT that wrap the macro body, the first for setting the font of the stream to the specified style and the other for restoring the default: (DEFMACRO WITH-TEXT-STYLE ((STREAM &KEY FAMILY SIZE FACE) &BODY BODY) (ONCE-ONLY (STREAM) `(UNWIND-PROTECT (PROGN (IL:PRINTOUT ,STREAM IL:.FONT (TEXT-STYLE-TO-FD ,FAMILY ,SIZE ,FACE)) ,@BODY) (IL:PRINTOUT ,STREAM IL:.FONT DEFAULT-FONT)))) PRINTOUT is an Interlisp function for formatted output similar to Common Lisp's FORMAT but with additional font control via the .FONT directive. The symbols of PRINTOUT, i.e. its directives and arguments, are in the Interlisp package. In turn GUI:WITH-TEXT-STYLE calls GUI::TEXT-STYLE-TO-FD, an internal DandeGUI function which passes to .FONT a font descriptor matching the required text attributes. GUI::TEXT-STYLE-TO-FD calls IL:FONTCOPY to build a descriptor that merges the specified attributes with any unspecified ones copied from the default font. The font descriptor is an Interlisp data structure that represents a font on the Medley environment. #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/changing-text-style-for-dandegui-window-output"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>

a month ago 22 votes
Adding window clearing and message printing to DandeGUI

<![CDATA[I continued working on DandeGUI, a GUI library for Medley Interlisp I'm writing in Common Lisp. I added two new short public functions, GUI:CLEAR-WINDOW and GUI:PRINT-MESSAGE, and fixed a bug in some internal code. GUI:CLEAR-WINDOW deletes the text of the window associated with the Interlisp TEXTSTREAM passed as the argument: (DEFUN CLEAR-WINDOW (STREAM) "Delete all the text of the window associated with STREAM. Returns STREAM" (WITH-WRITE-ENABLED (STR STREAM) (IL:TEDIT.DELETE STR 1 (IL:TEDIT.NCHARS STR))) STREAM) It's little more than a call to the TEdit API function IL:TEDIT.DELETE for deleting text in the editor buffer, wrapped in the internal macro GUI::WITH-WRITE-ENABLED that establishes a context for write access to a window. I also wrote GUI:PRINT-MESSAGE. This function prints a message to the prompt area of the window associated with the TEXTSTREAM passed as an argument, optionally clearing the area prior to printing. The prompt area is a one-line Interlisp prompt window attached above the title bar of the TEdit window where the editor displays errors and status messages. (DEFUN PRINT-MESSAGE (STREAM MESSAGE &OPTIONAL DONT-CLEAR-P) "Print MESSAGE to the prompt area of the window associated with STREAM. If DONT-CLEAR-P is non NIL the area will be cleared first. Returns STREAM." (IL:TEDIT.PROMPTPRINT STREAM MESSAGE (NOT DONT-CLEAR-P)) STREAM) GUI:PRINT-MESSAGE just passes the appropriate arguments to the TEdit API function IL:TEDIT.PROMPTPRINT which does the actual printing. The documentation of both functions is in the API reference on the project repo. Testing DandeGUI revealed that sometimes text wasn't appended to the end but inserted at the beginning of windows. To address the issue I changed GUI::WITH-WRITE-ENABLED to ensure the file pointer of the stream is set to the end of the file (i.e -1) prior to passing control to output functions. The fix was to add a call to the Interlisp function IL:SETFILEPTR: (IL:SETFILEPTR ,STREAM -1) #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/adding-window-clearing-and-message-printing-to-dandegui"Discuss.../a Email | Reply @amoroso@oldbytes.space !--emailsub--]]>

2 months ago 15 votes
DandeGUI, a GUI library for Medley Interlisp

<![CDATA[I'm working on DandeGUI, a Common Lisp GUI library for simple text and graphics output on Medley Interlisp. The name, pronounced "dandy guy", is a nod to the Dandelion workstation, one of the Xerox D-machines Interlisp-D ran on in the 1980s. DandeGUI allows the creation and management of windows for stream-based text and graphics output. It captures typical GUI patterns of the Medley environment such as printing text to a window instead of the standard output. The main window of this screenshot was created by the code shown above it. A text output window created with DandeGUI on Medley Interlisp and the Lisp code that generated it. The library is written in Common Lisp and exposes its functionality as an API callable from Common Lisp and Interlisp code. Motivations In most of my prior Lisp projects I wrote programs that print text to windows. In general these windows are actually not bare Medley windows but running instances of the TEdit rich-text editor. Driving a full editor instead of directly creating windows may be overkill, but I get for free content scrolling as well as window resizing and repainting which TEdit handles automatically. Moreover, TEdit windows have an associated TEXTSTREAM, an Interlisp data structure for text stream I/O. A TEXTSTREAM can be passed to any Common Lisp or Interlisp output function that takes a stream as an argument such as PRINC, FORMAT, and PRIN1. For example, if S is the TEXTSTREAM associated with a TEdit window, (FORMAT S "~&Hello, Medley!~%") inserts the text "Hello, Medley!" in the window at the position of the cursor. Simple and versatile. As I wrote more GUI code, recurring patterns and boilerplate emerged. These programs usually create a new TEdit window; set up the title and other options; fetch the associated text stream; and return it for further use. The rest of the program prints application specific text to the stream and hence to the window. These patterns were ripe for abstracting and packaging in a library that other programs can call. This work is also good experience with API design. Usage An example best illustrates what DandeGUI can do and how to use it. Suppose you want to display in a window some text such as a table of square roots. This code creates the table in the screenshot above: (gui:with-output-to-window (stream :title "Table of square roots") (format stream "~&Number~40TSquare Root~2%") (loop for n from 1 to 30 do (format stream "~&~4D~40T~8,4F~%" n (sqrt n)))) DandeGUI exports all the public symbols from the DANDEGUI package with nickname GUI. The macro GUI:WITH-OUTPUT-TO-WINDOW creates a new TEdit window with title specified by :TITLE, and establishes a context in which the variable STREAM is bound to the stream associated with the window. The rest of the code prints the table by repeatedly calling the Common Lisp function FORMAT with the stream. GUI:WITH-OUTPUT-TO-WINDOW is best suited for one-off output as the stream is no longer accessible outside of its scope. To retain the stream and send output in a series of steps, or from different parts of the program, you need a combination of GUI:OPEN-WINDOW-STREAM and GUI:WITH-WINDOW-STREAM. The former opens and returns a new window stream which may later be used by FORMAT and other stream output functions. These functions must be wrapped in calls to the macro GUI:WITH-WINDOW-STREAM to establish a context in which a variable is bound to the appropriate stream. The DandeGUI documentation on the project repository provides more details, sample code, and the API reference. Design DandeGUI is a thin wrapper around the Interlisp system facilities that provide the underlying functionality. The main reason for a thin wrapper is to have a simple API that covers the most common user interface patterns. Despite the simplicity, the library takes care of a lot of the complexity of managing Medley GUIs such as content scrolling and window repainting and resizing. A thin wrapper doesn't hide much the data structures ubiquitous in Medley GUIs such as menus and font descriptors. This is a plus as the programmer leverages prior knowledge of these facilities. So far I have no clear idea how DandeGUI may evolve. One more reason not to deepen the wrapper too much without a clear direction. The user needs not know whether DandeGUI packs TEdit or ordinary windows under the hood. Therefore, another design goal is to hide this implementation detail. DandeGUI, for example, disables the main command menu of TEdit and sets the editor buffer to read-only so that typing in the window doesn't change the text accidentally. Using Medley Common Lisp DandeGUI relies on basic Common Lisp features. Although the Medley Common Lisp implementation is not ANSI compliant it provides all I need, with one exception. The function DANDEGUI:WINDOW-TITLE returns the title of a window and allows to set it with a SETF function. However, the SEdit structure editor and the File Manager of Medley don't support or track function names that are lists such as (SETF WINDOW-TITLE). A good workaround is to define SETF functions with DEFSETF which Medley does support along with the CLtL macro DEFINE-SETF-METHOD. Next steps At present DandeGUI doesn't do much more than what described here. To enhance this foundation I'll likely allow to clear existing text and give control over where to insert text in windows, such as at the beginning or end. DandeGUI will also have rich text facilities like printing in bold or changing fonts. The windows of some of my programs have an attached menu of commands and a status area for displaying errors and other messages. I will eventually implement such menu-ed windows. To support programs that do graphics output I plan to leverage the functionality of Sketch for graphics in a way similar to how I build upon TEdit for text. Sketch is the line drawing editor of Medley. The Interlisp graphics primitives require as an argument a DISPLAYSTREAM, a data stracture that represents an output sink for graphics. It is possible to use the Sketch drawing area as an output destination by associating a DISPLAYSTREAM with the editor's window. Like TEdit, Sketch takes care of repainting content as well as window scrolling and resizing. In other words, DISPLAYSTREAM is to Sketch what TEXTSTREAM is to TEdit. DandeGUI will create and manage Sketch windows with associated streams suitable for use as the DISPLAYSTREAM the graphics primitives require. #DandeGUI #CommonLisp #Interlisp #Lisp a href="https://remark.as/p/journal.paoloamoroso.com/dandegui-a-gui-library-for-medley-interlisp"Discuss.../a Email | Reply @amoroso@fosstodon.org !--emailsub--]]>

2 months ago 26 votes

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Single-Use Disposable Applications

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12 hours ago 3 votes
Thoughts on Motivation and My 40-Year Career

I’ve never published an essay quite like this. I’ve written about my life before, reams of stuff actually, because that’s how I process what I think, but never for public consumption. I’ve been pushing myself to write more lately because my co-authors and I have a whole fucking book to write between now and October. […]

7 hours ago 3 votes
Desktop UI frameworks written by a single person

Less known desktop UI frameworks Writing desktop software is hard. The UI technologies of Windows or MacOS are awful compared to web technology. What can trivially be done with HTML/CSS/JavaScript in few minutes can take hours using Windows’s win32 APIs or Mac’s Cocoa. That’s why the default technology for desktop apps, especially cross-platform, is Electron: a Chrome browser combined with Node runtime. The problem is that it’s bloaty: each app is a unique build of Chrome with a little bit of application code. Chrome is over 100MB so many apps ship less than 1MB of code in a 100M wrapper. People tried to address the problem of poor OS APIs by writing UI frameworks, often meant to be cross-platform. You’ve heard about QT, GTK, wxWindows. The problem with those is that they are also old, their APIs are not the greatest either and they are bloaty as well. There just doesn’t seem to be a good option. Writing your own framework seems impossible due to the size of task. But is it? I’ll show a couple of less-known UI frameworks written mostly be a single person, often done simply to enable writing an application. SWELL in WDL WDL is interesting. Justin Frankel, the guy who created Winamp, has a repository of C++ code he uses in different projects. After selling Winamp to AOL, a side quest of writing file sharing application, getting fired from AOL for writing file sharing application, he started a company building Reaper a digital audio workstation software for Windows. Winamp is a win32 API program and so is Reaper. At some point Justin decided to make a Mac version but by then he had a lot of code heavily using win32 APIs. So he did what anyone in his position would: he implemented win32 APIs for Mac OS and Linux and called it SWELL - Simple Windows Emulation Layer. Ok, actually no-one else would do it. It was an insane idea but it worked. It’s important to not over-state SWELL capabilities. It’s not Wine. You can’t take any win32 program and recompile for Mac with SWELL. Frankel is insanely pragmatic and so is his code. SWELL only implements the subset of APIs he uses in Reaper. At the same time Reaper is a big app so if SWELL works for Reaper, it could work for your app. WDL is open-source using permissive MIT license. Sublime Text For a few years Sublime Text was THE programmer’s editor. It was written by a single developer in C++ and he wrote a custom UI toolkit for it. Not open source but its existence shows it can be done. RAD Debugger RAD Debugger is an open-source Windows debugger for C/C++ apps written in C by mostly a single person. It implements a custom UI framework based on 3D renderer. The UI is integral part of the the app but the code is well structured so you probably can take just their UI / render code and use it in your own C / C++ app. Currently the app / UI is only for Windows but it’s designed to be cross-platform and they are working on porting the renderer to Mac OS / Linux. They use permissive MIT license and everything is written in C. Dear ImGUI Dear ImGui is a newer cross-platform, UI framework in C++. Open source, permissive MIT license. Written by mostly a single person. Ghostty Ghostty is a cross-platform terminal emulator and UI. It’s written in Zig by mostly a single person and uses it’s own low-level GPU renderer for the UI. You too can write your own UI framework At first the idea of writing your own UI framework seems impossibly daunting. What I’m hoping to show is that if you’re ambitious enough it’s possible to build cross platform desktop apps that are not just bloated 100MB Chrome wrappers around few kilobytes of custom code. I’m not saying it’s a simple thing, just that enough people did it that it’s possible. It shouldn’t be necessary but both Microsoft and Apple have tragically dropped the ball on providing decent, high-performance UI libraries for their OS. Microsoft even writes their own apps, like Teams, in web technologies. Thanks to open source you’re not at the staring line. You can just use Dear ImGUI or WDL’s SWELL. Or you can extract the UI code from RAD Debugger or Ghostty (if you write in Zig). Or you can look at how their implementation to speed up your own design and implementation.

yesterday 2 votes
Logic for Programmers Turns One

I released Logic for Programmers exactly one year ago today. It feels weird to celebrate the anniversary of something that isn't 1.0 yet, but software projects have a proud tradition of celebrating a dozen anniversaries before 1.0. I wanted to share about what's changed in the past year and the work for the next six+ months. The Road to 0.1 I had been noodling on the idea of a logic book since the pandemic. The first time I wrote about it on the newsletter was in 2021! Then I said that it would be done by June and would be "under 50 pages". The idea was to cover logic as a "soft skill" that helped you think about things like requirements and stuff. That version sucked. If you want to see how much it sucked, I put it up on Patreon. Then I slept on the next draft for three years. Then in 2024 a lot of business fell through and I had a lot of free time, so with the help of Saul Pwanson I rewrote the book. This time I emphasized breadth over depth, trying to cover a lot more techniques. I also decided to self-publish it instead of pitching it to a publisher. Not going the traditional route would mean I would be responsible for paying for editing, advertising, graphic design etc, but I hoped that would be compensated by much higher royalties. It also meant I could release the book in early access and use early sales to fund further improvements. So I wrote up a draft in Sphinx, compiled it to LaTeX, and uploaded the PDF to leanpub. That was in June 2024. Since then I kept to a monthly cadence of updates, missing once in November (short-notice contract) and once last month (Systems Distributed). The book's now on v0.10. What's changed? A LOT v0.1 was very obviously an alpha, and I have made a lot of improvements since then. For one, the book no longer looks like a Sphinx manual. Compare! Also, the content is very, very different. v0.1 was 19,000 words, v.10 is 31,000.1 This comes from new chapters on TLA+, constraint/SMT solving, logic programming, and major expansions to the existing chapters. Originally, "Simplifying Conditionals" was 600 words. Six hundred words! It almost fit in two pages! The chapter is now 2600 words, now covering condition lifting, quantifier manipulation, helper predicates, and set optimizations. All the other chapters have either gotten similar facelifts or are scheduled to get facelifts. The last big change is the addition of book assets. Originally you had to manually copy over all of the code to try it out, which is a problem when there are samples in eight distinct languages! Now there are ready-to-go examples for each chapter, with instructions on how to set up each programming environment. This is also nice because it gives me breaks from writing to code instead. How did the book do? Leanpub's all-time visualizations are terrible, so I'll just give the summary: 1180 copies sold, $18,241 in royalties. That's a lot of money for something that isn't fully out yet! By comparison, Practical TLA+ has made me less than half of that, despite selling over 5x as many books. Self-publishing was the right choice! In that time I've paid about $400 for the book cover (worth it) and maybe $800 in Leanpub's advertising service (probably not worth it). Right now that doesn't come close to making back the time investment, but I think it can get there post-release. I believe there's a lot more potential customers via marketing. I think post-release 10k copies sold is within reach. Where is the book going? The main content work is rewrites: many of the chapters have not meaningfully changed since 1.0, so I am going through and rewriting them from scratch. So far four of the ten chapters have been rewritten. My (admittedly ambitious) goal is to rewrite three of them by the end of this month and another three by the end of next. I also want to do final passes on the rewritten chapters; as most of them have a few TODOs left lying around. (Also somehow in starting this newsletter and publishing it I realized that one of the chapters might be better split into two chapters, so there could well-be a tenth technique in v0.11 or v0.12!) After that, I will pass it to a copy editor while I work on improving the layout, making images, and indexing. I want to have something worthy of printing on a dead tree by 1.0. In terms of timelines, I am very roughly estimating something like this: Summer: final big changes and rewrites Early Autumn: graphic design and copy editing Late Autumn: proofing, figuring out printing stuff Winter: final ebook and initial print releases of 1.0. (If you know a service that helps get self-published books "past the finish line", I'd love to hear about it! Preferably something that works for a fee, not part of royalties.) This timeline may be disrupted by official client work, like a new TLA+ contract or a conference invitation. Needless to say, I am incredibly excited to complete this book and share the final version with you all. This is a book I wished for years ago, a book I wrote because nobody else would. It fills a critical gap in software educational material, and someday soon I'll be able to put a copy on my bookshelf. It's exhilarating and terrifying and above all, satisfying. It's also 150 pages vs 50 pages, but admittedly this is partially because I made the book smaller with a larger font. ↩

2 days ago 4 votes
Implementing UI translation in SumatraPDF, a C++ Windows application

Translating user interface of SumatraPDF SumatraPDF is the best PDF/eBook/Comic Book viewer for Windows. It’s small, fast, full of features, free and open-source. It became popular enough that it made sense to translate the UI for non-English users. Currently we support 72 languages. This article describes how I designed and implemented a translation system in SumatraPDF, a native win32 C++ Windows application. Hard things about translating the UI There are 2 hard things about translating an application code for translation system (extracting strings to translate, translate strings from English to user’s language) translating them into many languages Extracting strings to translate from source code Currently there are 381 strings in SumatraPDF subject to translation. It’s important that the system requires the least amount of effort when adding new strings to translate. Every string that needs to be translated is marked in .cpp or .h file with one of two macros: _TRA("Rename") _TRN("Open") I have a script that extracts those strings from source files. Mine is written in Go but it could just as well be Python or JavaScript. It’s a simple regex job. _TR stands for “translation”. _TRA(s) expands into const char* trans::GetTranslation(const char* str) function which returns str translated to current UI language. We auto-detect language at startup based on Windows settings and allow the user to explicitly set UI language. For English we just return the original string. If a string to be translated is e.g. a part of const char* array[], we can’t use trans::GetTranslation(). For cases like that we have _TRN() which expands to English string. We have to write code to translate it at some point. Adding new strings is therefore as simple as wrapping them in _TRA() or _TRN() macros. Translating strings into many languages Now that we’ve extracted strings to be translated, we need to translate them into 72 languages. SumatraPDF is a free, open-source program. I don’t have a budget to hire translators. I don’t have a budget, period. The only option was to get help from SumatraPDF users. It was vital to make it very easy for users to send me translations. I didn’t want to ask them, for example, to download some translation software. Design and implementation of AppTranslator web app I couldn’t find a really simple software for crowd sourcing translations so I wrote my own: https://github.com/kjk/apptranslator You can see it in action: https://www.apptranslator.org/app/SumatraPDF I designed it to be generic but I don’t think anyone else is using it. AppTranslator is simple. Per https://tools.arslexis.io/wc/: 4k lines of Go server code 451 lines of html code a single dependency: bootstrap CSS framework (the project is old) It’s simple because I don’t want to spend a lot of time writing translation software. It’s just a side project in service of the goal of translating SumatraPDF. Login is exclusively via GitHub. It doesn’t even use a database. Like in Redis, changes are stored as a series of operations in an append-only log. We keep the whole state in memory and re-create it from the log at startup. Main operation is translate a string from English to language X represented as [kOpTranslation, english string, language, translation, user who provided translation]. When user provides a translation in the web UI, we send an API call to the server which appends the translation operation to the log. Simple and reliable. Because the code is written in Go, it’s very fast and memory efficient. When running it uses mere megabytes of RAM. It can comfortably run on the smallest 256 MB VPS server. I backup the log to S3 so if the server ever fails, I can re-install the program on a new server and re-download the translations from S3. I provide RSS feed for each language so that people who provide translations can monitor for new strings to be translated. Sending strings for translation and receiving translations So I have a web app for collecting translations and a script that extracts strings to be translated from source code. How do they connect? AppTranslator has an API for submitting the current set of strings to be translated in the simplest possible format: a line for each string (I ensure there are no newlines in the string itself by escaping them with \n) API is password protected because only I can submit the strings. The server compares the strings sent with the current set and records a difference in the log. It also sends a response with translations. Again the simplest possible format: AppTranslator: SumatraPDF 651b739d7fa110911f25563c933f42b1d37590f8 :%s annotation. Ctrl+click to edit. am:%s մեկնաբանություն: Ctrl+քլիք՝ խմբագրելու համար: ar:ملاحظة %s. اضغط Ctrl للتحرير. az:Qeyd %s. Düzəliş etmək üçün Ctrl+düyməyə basın. As you can see: a string to translate is on a line starting with : is followed by translations of that strings in the format: ${lang}: ${translation} An optimization: 651b739d7fa110911f25563c933f42b1d37590f8 is a hash of this response. If I submit this hash with my request and translations didn’t change on the server, the response is empty. Implementing C++ part of translation system So now I have a text file with translation downloaded from the server. How do I get a translation in my C++ code? As with everything in SumatraPDF, I try to do things in a simple and efficient way. The whole Translation.cpp is only 239 lines of code. The core of translation system is const char* trans::GetTranslation(const char* s); function. I embed the translations in exact the same format as received from AppTranslator in the executable as data file in resources. If the UI language is English, we do nothing. trans::GetTranslation() returns its argument. When we switch the language, we load the translations from resources and build an index: an array of English strings an array of corresponding translations Both arrays use my own StrVec class optimized for storing an array of strings. To find a translation we scan the first array to find an index of the string and return translation from the second array, at the same index. Linear scan seems like it would be slow but it isn’t. Resizing dialogs I have a few dialogs defined in SumatraPDF.rc file. The problem with dialogs is that position of UI elements is fixed. A translated string will almost certainly have a different size than the English string which will mess up fixed layout. Thankfully someone wrote DialogSizer that smartly resizes dialogs and solves this problem. The evolution of a solution No AppTranslator My initial implementation was simpler. I didn’t yet have AppTranslator so I stored the strings in a text file in repository in the same format as what I described above. People would download it, make changes using a text editor and send me the file via email which I would then checkin. It worked for a while but it became worse over time. More strings, more languages created more work for me to manually manage e-mail submissions. I decided to automate the process. Code generation My first implementation of C++ side used code generation instead of embedding the text file in resources. My Go script would generate C++ source code files with static const char* [] arrays. This worked well but I decided to improve it further by making the code use the text file with translations embedded in the app. The main motivation for the change was to open a possibility of downloading latest translations from the server to fix the problem of translations not being all ready when I build the release executable. I haven’t done that yet but it’s now easier to implement given that the format of strings embedded in the exe is the same as the one I can download from AppTranslator. Only utf-8 SumatraPDF started by using both WCHAR* Unicode strings and char* utf8 strings. For that reason the translation system had to support returning translation in both WCHAR* and char* version. Over time I refactored the code to use mostly utf8 and at some point I no longer needed to support WCHAR* version. That made the code even smaller and reduced memory usage. The experience I’m happy how things turned out. AppTranslator proved to be reliable and hassle free. It runs for many years now and collected 35440 string translations from users. I automated everything so that all I need to do is to periodically re-run the script that extracts strings from source code, uploads them to AppTranslator and downloads latest translations. One problem is that translations are not always ready in time for release so I make a release and then people start translating strings added since last release. I’ve considered downloading the latest translations from the server, in addition to embedding them in an executable at the time of building the app. Would I do the same today? While AppTranslator is reliable and doesn’t require on-going work, it would be better to not have to run a server at all. The world has changed since I started SumatraPDF. Namely: people are comfortable using GitHub and you can edit files directly in GitHub UI. It’s not a great experience but it works. One option would be to generate a translation text file for each language, in this format: :first untranslated string :second untranslated string :first translated string translation of first string :second translated string translation of second string Untranslated strings are listed at the top, to make it easier to find. A link would send a translator directly to edit this file in GitHub UI. When translator saves translations, it creates a PR for me to review and merge. The roads not taken But why did you re-invent everything? You should do X instead. All other X that I know about suck. Using per-language .rc resource files Traditional way of localizing / translating Window GUI apps is to store all strings and dialog definitions in an .rc file. Each language gets its own .rc file (or files) and the program picks the right resource based on a language. This doesn’t solve the 2 hard problems: having an easy way to add strings for translations having an easy way for users to provide translations XML horror show There was a dark time when the world was under the iron grip of XML fanaticism. Everything had to be an XML file even when it was the worst possible solution for the problem. XML doesn’t solve the 2 hard problems and a string storage format is an absolute nightmare for human editing. GNU gettext There’s a C library gettext that uses .po files. This is much saner solution than XML horror show. .po files are relatively simple text format. The code is already written. Warning: tooting my own horn. My format is better. It’s easier for people to edit, it’s easier to write code to parse it. This looks like many times more than 239 lines of code. Ok, gettext probably does a bit more than my code, but clearly nothing than I need. It also doesn’t solve the 2 hard problems. I would still have to write code to extract strings from source code and build a way to allow users to translate them easily.

2 days ago 3 votes