(评论)
(comments)

原始链接: https://news.ycombinator.com/item?id=41261426

要与 Free Pascal 中的现有库交互,您可能需要使用 C 库、C 桥或第三方桥(例如“Python-for-Lazarus”)创建通用抽象二进制接口 (CABI)。 对于更简单的任务,可以直接使用Python库。 然而,所选的库以及您对 Free Pascal 的熟悉程度起着重要作用。 FPC 中包含的 h2pas 实用程序可帮助根据给定的 C 头文件生成代码。 请记住,可能需要进行调整才能获得最佳性能。 另请注意,较大的项目在编译过程中可能需要相当长的时间,特别是在较旧的硬件上。 虽然 Free Pascal 具有许多优点,但学习其复杂性需要一定程度的奉献精神,这对初学者来说具有挑战性。 尽管如此,对于那些希望访问现有库并利用 Free Pascal 和 Lazarus 提供的优势的人来说,它仍然是一个可行的选择。

相关文章

原文


What does this comment mean? Since not particularly well-versed in programming, all I understood was that this project has something that can read data? What is impressive about a tool that can read C++?

Would appreciate if someone can explain, thanks!



I think "pretty close" is severely underselling Lazarus - it is way ahead of Visual Basic 6 in almost every aspect when it comes to making GUIs. Even Delphi 2 (the first 32bit Delphi) allowed for more complex GUIs compared to VB6, let alone something way more advanced like Lazarus.

The only thing that VB up to 6 had that you can't find in Lazarus (or Delphi for that matter) is being able to pause the program while it is running (or some error occurred), modify it and continue the execution without restarting it. But overall considering all the pros Lazarus has compared to VB6 i'd say it is much better than VB6 ever was.



Lazarus seems amazing, and I'd love to write some software with it, but I can't get past the language. You generally do want to pick languages with a big ecosystem, as everything you might want will have already been written.

The difference between Python and Delphi isn't a bit more work, it's often the difference between "there's a library so I can make my thing" and "it would take way too long".



You can interface with existing libraries if you really want, you need to somehow expose a C ABI (be it via the library written in C, exposing an official C ABI or you writing a C bridge).

There is a 3rd party "Python-for-Lazarus" bridge[0] though for simple stuff you can use the python library directly:

    program foo;
    {$MODE OBJFPC}
    uses CTypes;
    const PyLib = 'python3.11';
    procedure Py_Initialize; cdecl; external PyLib;
    function PyRun_SimpleString(Command: PChar): CInt; cdecl; external PyLib;
    begin
      Py_Initialize;
      PyRun_SimpleString(
        'from tkinter import *'#13 +
        'window = Tk()'#13 +
        'window.title("Hello, world!")'#13 +
        'button = Button(window, text="Clicky")'#13 +
        'button.grid()'#13 +
        'window.mainloop()');
    end.
The above uses the Tk library that comes with Python.

Also depending on what you want to do chances are there is already a Free Pascal library or existing bindings to a library written in another language. If not, if the library has a C header file you can use the h2pas utility that comes with FPC to make your own (though the generated code does need some modifications to work more often than not).

Of course all the above do assume you have knowledge of both Free Pascal and whatever you want to interface with, but at least as far as being able to access existing libraries is concerned, it should be possible - just with some hoops (and at that point it depends on how much you value whatever Lazarus provides over the effort involved in whatever library you want to use).

EDIT: and truth be told IMO the biggest roadblock with Lazarus isn't so much the language but that it is just not easy to learn most of that stuff (the core language and runtime library is decently documented but anything outside of that can be a hit and miss) and you basically need an almost arrogant attitude of "this is just dumb code, not magic, if it is technically possible i can figure out myself how to do it" :-P.

[0] https://github.com/Alexey-T/Python-for-Lazarus



Pascal is a workhorse and to tame the horse takes a lot of skill and blind knowledge. And then when tamed, your horse is the best at the show.

I can't fault Pascal. It may not have every module ever like Python, it's syntax may feel archaic but the satisfaction and feel of producing a program with is fuzzy feeling great.

I enjoy making my own things, especially wheels.



"VB6 was not very flexible in many ways but you could get an application going in no time"

Same in Delphi / Lazarus. And the language was / is way more powerful.



More or less, depending on many factors though. In general it is among the most lightweight IDEs, i've even used it on an original Raspberry Pi (though that was a few years ago) - it wasn't fast there, but it was usable which is more than can be said about most other still developed IDEs.

Free Pascal is not as fast as Delphi 2 (especially if the target OS needs to use a native linker like GNU ld), for some decently sized projects it can take several seconds (or even a minute for multimillion lines of code) for a full build, though partial builds tend to be almost instant - at least in hardware released within the last 10 years (and SSDs help, like everywhere else). Of course both the language and the libraries (and Lazarus itself as an IDE and its own framework) do way more than Delphi 2, which itself was also more advanced than VB6.

I do believe that the provided functionality scales well with its requirements.

I'm not sure about a 400MHz P3, but i have tried a git build of Lazarus from last year on a late 2003 Athlon64 PC running Windows 7 and was very comfortable. A 400MHz P3 would be faster than an original Raspberry Pi, so i'd expect that if nothing else to be usable though might not be as comfortable as VB6 (or Delphi 2 for that matter). I do have a (IIRC) 800MHz P3 around for retro games, at some point i might try to install some lightweight Linux for fun and try to see how it performs there.



That sounds very competitive. One, more question.

I used to use VB6 partly just for quickly drawing GUI’s, esp getting size right. Lazarus was one of free tools I found that was similar but most prefer other languages.

Is there a way to make a GUI in Lazarus, save it to a file with types/dimensions, and then some other tool could generate a non-Pascal GUI from it? Does it have an export ability that’s detailed and parsable enough for that?



> I wish it had C++ support as well, akin to C++Builder. Pascal syntax is off-putting for many

I write my "app" as a library (.dll/.so) in C and use Lazarus to do the GUI, because FFI from FreePascal to C (and back again, for callbacks) is almost transparent.



It'd be neat but that would require a ton of effort and cooperation by several different projects.

Basically you'd need a C++ compiler to implement the C++ extensions used by C++ Builder (or something similar if you don't care about C++ Builder compatibility) so that C++ code can use Object Pascal methods with the extra functionality it adds (most important being properties and "published" sections in class declarations that are exposed via RTTI). You'd also need some tool to create C++ bindings for all the Free Pascal units.

The above will make possible to use LCL from C++, though only via code.

To get the full RAD deal you'd need to implement a C++ parser (including the extensions mentioned above) and refactoring support for Lazarus' CodeTools equivalent to the existing Free Pascal parser/refactoring so that the IDE can autogenerate code (Lazarus doesn't generate separate source code files like some other IDEs with GUI designers do, instead it updates the same source code you are editing on the fly as it keeps a full AST in memory for all edited files and units they depend on - something like that would be needed for C++ too).

And yeah, you'd need the people involved with all the above (really mainly the C++ compiler developers) to play along without breaking stuff.



Interface Builder and Project Center on NeXTstep were amazing --- see Steve Job's 5-minute word processor demo.

For a large-scale real world project example consider that the NeXT version of Wordperfect was done is 6 weeks or so --- granted it started w/ a working Unix version, but it felt fully native and nicely polished (and was much better than the Windows version).



Given that Python appears to be the new VB6/VBA (in terms of adoption by a non-SWE user base), IMO there's still a gap for a decent VB6-like RAD experience within the Python ecosystem.

Qt Designer exists, but PyQt/PySide licencing can cause headaches.



I'd give a lot for there to be a simple tool for Python which:

- had an interactive tool for laying out a GUI

- integrated that layout into the code in a meaningful fashion

- allowed distributing a project as a single file which could be easily run (say by downloading/installing a single run-time module)

The problem is, for each computer I use I need to keep track of which Python environment(s) have been installed where, (and uninstall them) or I end up with something like:

https://xkcd.com/1987/

(well, at least something which won't allow me to get a new project installed).



... or a more full featured experience than Delphi.

VB fails (or used to, haven't worked with it in a looong time) when you want to do custom controls and integrate them in the UI builder. With Delphi that used to be piss easy, you could even write designer-only methods that helped with custom configuring your controls, while with VB you had to do it in something else iirc. Too bad Embarcadero only wants to sell to enterprises that are stuck on legacy applications.

And what's with all the Pascal hate? Missing your <> and {}? Nothing wrong with begin and end.

What I wonder is: if the Rust crowd is hell bent on rewriting everything, why don't they clone the VCL and the GUI designer?



Godot or Unity? Why would you build a regular application GUI with that?

Those are for running a game or game like application constantly at XX fps, not for something that reacts to user input and should consume 0% cpu when it's not told to do anything.

Please tell me "modern" UI toolkits are still event driven and don't infinitely render everything in a loop like a game...



the thread you have (apparently unintentionally) posted this comment in is entitled 'ImRAD is a GUI builder for [an] ImGui library [for opengl]' :-)

more generally, guis that don't need to run constantly at xx fps don't have much reason to not be written in html5



Oh :(

I thought ImGui was a regular GUI library.

Why are people even mentioning VB6 and Delphi then in the comment threads?

Possibly because they made the same assumption that I made :)



imgui is a general approach to designing gui libraries proposed by casey muratori in 02005 https://www.youtube.com/watch?v=Z1qyvQsjK5Y; the particular library in question is omar cornut's 'dear imgui'

a gui that would use 100% of cpu on an 0.52-mips mac 512 https://netlib.org/performance/html/dhrystone.data.col0.html would probably use about 0.02% of cpu on one 2201-mips core of a raspberry pi 3 https://netlib.org/performance/html/dhrystone.data.col0.html

if you pessimistically multiply that by 32 to account for having 32 bits per pixel instead of 1, and by 12 to account for 1920×1080 instead of 512×342, it comes to 9%. of one of the cores! also it would run in 0.5% of the pi's ram

so, to a significant extent, the struggle is no longer to get something approximating your desired user interface running, but to imagine a user interface that's worth people's time to use. so it makes sense to trade off cpu consumption and ram usage for faster experimentation in a lot of cases



> it comes to 9%. of one of the cores! also it would run in 0.5% of the pi's ram

9% from one app, 9% from another, pretty soon we're talking about real power consumption / battery life

And even the 9% that you find trivial is something I, as an user, could use for something that gives me a benefit instead of your game-like GUI.

> so it makes sense to trade off cpu consumption and ram usage for faster experimentation in a lot of cases

It does not. If it has nothing animated, you'd better not redraw it. Anything else is lack of respect for the user's resources.



I recently saw a tweet where a programmer demanded that all UIs (and presumably their frameworks/toolkits) should be immediate mode.

So, yeah, there seems to be some desire for that kind of thing out in the wild these days.



react is immediate mode, and it doesn't have to refresh at xx fps; it only refreshes when a change in the data the gui is dependent on. (and the browser tends to refresh when there are input events)



This is the kind of thing that can easily devolve into a semantic argument. React presents an immediate mode like API but internally (both in the virtual DOM of React and within the actual DOM of the HTML document) the actual rendering path is very much retained mode.

The specific thread we are in isn't related to the benefits/drawbacks of API design but rather the performance implications of re-rendering the entire scene on every frame. As you mentioned, React doesn't re-render on every frame and therefore isn't really relevant to that discussion.



very plausibly the programmer you mentioned demanding that all uis be immediate mode was looking for the benefits/drawbacks of api design rather than the performance implications of re-rendering the entire scene on every frame; react shows one way they can be decoupled



They were talking about imgui, so no. Unless dear imgui is secretly an immediate mode API on top of a retained mode renderer?

Also, weren't you literally arguing in another thread that performance didn't matter? Some calculation about Raspberry Pis and percentages of cores? I'm starting to wonder how good faith of an argument is trying to be put forward here.



This would be cool built in a wasm html5 app to whip up a gui in the browser and copy paste the result into your editor.

> It generates and parses C++ code which can be directly used in your application.

Is the parsing part just to read it's own code it generates?



> This would be cool built in a wasm html5 app to whip up a gui in the browser and copy paste the result into your editor.

Forgot how to install and run native applications? :)

"ImRAD runs on Windows, Linux and MacOS."



Okay, for the sake of the argument, let's assume at some point you amortize the fixed costs of native compilation down to zero.

Tell me how running a native binary is inherently easier than opening a webpage?



You are confusing "Number of steps" with "Easy".

They're also the same number of steps. If I tell my OS to open an `html` file, it opens a browser window.



The user experience is still on a whole other level, not living inside the browser. And the number of times I've used a wasm app, more than once, that actually had some theft do it. Well, I can't think of a single one. So, we will see how well it does in practice.

Wasm is great, but if the goal is to move native applications do the webb it isn't something I look forward to.



I've thought about making a RAD IDE for another language, and I'm kind of stuck wondering on strategies for stuff like this, I'd much rather just store the GUI info in another format like XML and only parse source files for things like methods that shouldn't be overriden when someone moves something.

I really wish we'd go back to having a lot more RAD tools.



A multi-platform, minimal dependency project such as this is a perfect fit for targeting wasm, which of course is "just" another platform (not sure what additional dependencies you think it would need?)



Shouldn't it be "for the Dear library" given that the dear-imgui creator has stated it's named "dear"? (IMGUI means immediate-mode GUI, and ocornut has said he was inspired by another IMGUI named "simgui" [] )

> I renamed it to "dear imgui" (about 15 months later) because "imgui" has been hogging up the whole acronym. I am sorry for the confusion caused even today.

[] https://github.com/ocornut/imgui/issues/7892



Dear ImGui is the full official name, but it's still extremely common to refer to it simply as ImGui (that's what the namespace is called, etc). It's definitely not just "Dear".



You can see the interface while you're designing it. Meaning, instead of writing a bunch of code, compiling, running, deciding one widget needs to be moved a bit you can just see it and move it.

You also save time writing a ton of boilerplate.



> could it ever be used for non-gaming applications? Even Enterprise applications?

Applications typically need good text rendering and layout support (multiline, fonts, maybe RTL, etc.), which ImGUI lacks.



Taking a shot at a gentler version of the sibling comment.

If someone says "I made a thing," and a reply says "that's cool but I would rather have something slightly different that matches my technology of choice," I can't see any positive outcomes for anybody. For the submitter or author, the message is "what you made isn't good enough." For a reader without context, it purely muddies the waters because it adds noise without teaching them anything. For a reader with context, it's not new. I don't understand what the value could be for anyone.

Imagine someone submits an article about a MySQL ORM for Go, and the top comment is "now one in Ruby, please." How does that help anyone? It only diminishes the efforts of the submitter and ignores the complexity of writing an ORM in the first place.

If you want to start an effort to do something similar, then talk about doing that. If you want to tell people about another cool technology, do that. If you think the project under discussion could be extended to support something you want, pitch the value. If you want to make a feature request, you can definitely do that with more kindness for the creator.

I know from experience how annoying it is when random people come at you with tone critiques to your hastily written HN comments, so please take this as intended, just an attempt at building empathy.



I think I fired off that comment too quickly, on too little sleep, and it should have been more like "This is great! I really wish I had something similar for egui, a related toolkit." Thanks for your feedback. Apologies to all.



I didn't read it that way at all. I read it as a strong validation of the idea.

Like if I have cancer, and I read that they cured a different type of cancer, I'd be like, "now one for mine, please".

There's no implication here that curing that other cancer was a waste of time.



I don’t see an issue with that comment. Sometimes when people ask this, it opens another dimension of discussion and comparisons. Maybe there is already a library and someone will post it. Maybe it will encourage someone to create one, given that there are people out there requesting it. Among other positive reasons, not everything is negative or should be assumed that way.



I found the comment you replied to completely reasonable (see my other comment above).

You're making a lot of negative assumptions here, but more importantly, your comment is unpleasant beyond what they warrant, even if they were true.



How is "Now one for egui, please" not a request? Are you suggesting that was just a wish you're putting out into the universe hoping someone fulfills it? "please" is a word you use as a request, typically. Entitlement w.r.t open source just kills me.



> Are you suggesting that was just a wish you're putting out into the universe

There's the charitable interpretation of others I know you're capable of. One might even consider my comment as a starting point for other interested parties to discuss related functionality for a related toolkit. I don't know what others know. Perhaps there's one out there already?



I want to apologize. I just lashed out from my past bad experience. You don't really deserve it, and you're right, it could just open up a discussion about writing an alternative for egui. Sorry about that.



Thank you, and no worries. I appreciate that you took time to consider the interaction and write this, not everyone would. I'm sorry that my comment caused you distress of any sort. It wasn't my intention to demand anything from anyone, though I see how my comment could be interpreted that way. I'm really thankful for all the open source work done by other members of the community, and that's why I work to contribute everything I can. This is an exciting development for the imgui folks, and as an egui user, I'm just a little jealous! Here's hoping that all the toolkits get nice RAD builders sooner rather than later. I'd be happy to contribute to an egui effort.



> Now one for egui, please

>> How is "Now one for egui, please" not a request?

Relax. It's an idiomatic expression, perhaps you're not familiar with it, it doesn't usually signal entitlement.

联系我们 contact @ memedata.com