save and load a 2d array to a file
D
struct map_t{
int data[50][50];
} map;
//save
std.file.write("save.map", map.data); // compiles
//load
map.data = std.file.read("save.map", map.data.sizeof); // error
main.d(536): Error: cannot implicitly convert expression
`read("save.map", 2500LU)` of type `void[]` to `ubyte[50][]`
I'm guessing here, that internally we've got an array of arrays
(which means array of pointers), and D doesn't know how to split
by one of the axis. So how do I do that? If I know it's exactly
packed as it was before, can I smash it somehow by direct writing
a bunch of ubytes?
What is the 'smash' way to do it, and if better, what's the
elegant way to do it? (In case I need either going forward).
Thanks,
--Chris
Re: DUB issues
The dub creator shouldn't even remember creating this anymore. It makes me sad when I see that things in D are old, forgotten, outdated, abandoned. D is the best programming language in the world. But nobody appreciates it. It makes me sad when I see the repositories for over 10 years without an update, most things in dub are for Dlang 1 still.
Re: Can Enums be integral types?
On Sunday, 17 April 2022 at 18:25:32 UTC, Bastiaan Veelo wrote: On Saturday, 16 April 2022 at 11:39:01 UTC, Manfred Nowak wrote: In the specs(17) about enums the word "integral" has no match. But because the default basetype is `int`, which is an integral type, enums might be integral types whenever their basetype is an integral type. The reason is in [17.1.5](https://dlang.org/spec/enum.html): “EnumBaseType types cannot be implicitly cast to an enum type.” The 'integral' or numeric value is used for uniqueness, not for math or some other effect, anymore than a primary int key in a SQL database is used to identify someone's birthday. (*Maybe that's the wrong analogy, comparing apples to oranges perhaps*). We will indeed have to explicitly cast to get around it, though it doesn't mean much. If you have say true=1, blue=2, what is blue+true? Numerically it's 3 but there's no value 3, or value 3 could be say potato... Few years ago i made an enum type flag/library storage library, which would take an int and convert to N flags, or N flags to an int for compactly storing said values. But it's been quite a while, though i do recall a lot of casting and binary AND/OR/XOR's involved for it to work the way it was intended.
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On 4/18/22 09:17, Ali Çehreli wrote: > shared static ~this(): 0 > static ~this(): 0 >~this(): 8 Apologies for omitting 'scope' statements: scope(exit): 34 scope(success): 6 scope(failure): 8 Ali
Re: Install D lang on Windows 10 : an installation step by step tutorial made by a beginner who loves D !
On Monday, 18 April 2022 at 16:20:38 UTC, SMAOLAB wrote: After I noticed that if you don't install VisualD and Microsoft Visual Studio you may have issues (you don't see the DMD extension for instance, the PATH is not set) you should read : After I noticed that if you don't install **in the right order** VisualD and Microsoft Visual Studio you may have issues (you don't see the DMD extension for instance, the PATH is not set). sorry :-)
Re: Install D lang on Windows 10 : an installation step by step tutorial made by a beginner who loves D !
Dear Community, Thanks for your reactions/feedbacks. What went wrong when you used the DMD installer? Nothing really, the thing that went really wrong is the Microsoft Visual Studio (which licence I should install to get my D / Dplug program work). Next, I use LDC rather than DMD (but this only for my goal to develop DPLUG codes). After I noticed that if you don't install VisualD and Microsoft Visual Studio you may have issues (you don't see the DMD extension for instance, the PATH is not set) On Monday, 18 April 2022 at 09:04:24 UTC, Dennis wrote: I don't see the guide (explicitly) installing git, but I recall dub needing it to install packages. Is that covered? Yeap, I will add it and update the D-idioms. Thanks !
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On 4/17/22 17:35, Ali Çehreli wrote: > compared to C++, the amount of constructor, destructor, copy > constructor, etc. that I do *not* write in D is very liberating to me. > It feels like I just write what is needed and it mostly just works. The following is a quick and dirty grep-based stats from a largish successful project that implements multiple libraries and binaries. The figures are numbers of times each construct appears in source code: struct: 231 interface: 3 class: 12 union: 0 this(/* ... */): 72 [1] shared static this(): 8 static this(): 1 [2] shared static ~this(): 0 static ~this(): 0 ~this(): 8 this(this): 0 [3] [1] Most operations in most constructors are trivial assignments to members. [2] It contains just an enforce expression to ensure the environment is as expected. (It is an oversight that this is not a 'shared static this' as well.) [3] There are no copy constructors either because the project started with an older compiler. It is remarkable that I did not implement a single copy or move behavior ever. Compare that to countless C++ articles on attempting to teach how to deal with fundamental operations of object. Forgotten to be called or not, there are no 'move' (which does not move in C++) or 'forward' (which does not forward in C++) expressions at all. What a price the programming community keeps on paying just because their powerful programming language was there first... Ali
Re: Install D lang on Windows 10 : an installation step by step tutorial made by a beginner who loves D !
On Monday, 18 April 2022 at 09:04:24 UTC, Dennis wrote: What went wrong when you used the DMD installer? Installing Visual Studio should not be necessary, since DMD ships with the lld linker and MinGW Windows import libraries. If it doesn't work out of the box, it should be fixed. "Download and install Visual Studio 2019" is preselected in the installer, so you have to know to pick "Install VC2010 redistributables to use it with the MinGW Platform libraries" to opt out. I guess it's not *necessary* but it certainly encourages new users to install it. (I'd subjectively argue the VC2010/MinGW option should be the default, the whole of VS2019 is a very hefty download and not my IDE of choice.)
Re: Why do immutable variables need reference counting?
On Mon, Apr 18, 2022 at 12:55:26PM +, wjoe via Digitalmars-d-learn wrote: > On Sunday, 17 April 2022 at 14:14:37 UTC, H. S. Teoh wrote: > > Not entirely true. See paragraph 3 in: > > > > https://dlang.org/spec/unittest.html > > > > and 10.24.11.3 in: > > > > https://dlang.org/spec/expression.html#assert_expressions [...] > Thanks. Either I missed that the last time I checked or it wasn't > there ;) > But the interesting question is: does the compiler go out of its way > to make that happen or is it just paragraphs written in the spec? My guess: the spec was amended after the fact. :-D T -- Those who don't understand D are condemned to reinvent it, poorly. -- Daniel N
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Mon, Apr 18, 2022 at 08:22:26AM +, cc via Digitalmars-d-learn wrote: > On Monday, 18 April 2022 at 03:21:30 UTC, H. S. Teoh wrote: > > Structs in D ought to be treated like "glorified ints", as Andrei > > puts it. If you need complex ctors and complex methods, that's a > > sign you should be using a class instead. > > Unless you're having a nice quiet get-together with friends, and you > don't want to invite the GC, the biggest loudest party animal on the > block. Phobos's RefCounted seems to stretch the definition of > "glorified ints".. "Glorified int" includes pass-by-value types like pointers. Pointers / references wrapped in a struct is one of the more powerful D constructs that lets you do some pretty neat things. (Just don't expect it to behave like C++, lol. :-P) T -- Debian GNU/Linux: Cray on your desktop.
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Monday, 18 April 2022 at 13:21:44 UTC, zjh wrote: I hope that d can support it like `C++`. `Struct` and `class` behavior is inconsistent. `Constructors` sometimes have initialize behavior. If D doesn't think about `C++` users, `C++` users feel too troublesome, can't understand, and the cognitive burden is too heavy.
Re: DUB issues
On Monday, 18 April 2022 at 05:27:32 UTC, Danny Arends wrote: Any ideas how to get into contact/fix this issue ? I've emailed Sönke and pointed him to this thread.
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Sunday, 17 April 2022 at 15:13:29 UTC, HuskyNator wrote: This is a twofold question, along the example code below: The `default constructor` of `struct` is very convenient to use. I hope that d can support it like `C++`.
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Monday, 18 April 2022 at 10:26:16 UTC, HuskyNator wrote: On a sidenote, I'm surprised D did not choose 0 as the default floating value. Doesn't almost every language do this? I understand the thinking behind it, but when the type one uses in a template influences the behavior of the code, that seems like a pretty big red flag to me. (Any non-floating type defaults to 0, but using floats/doubles suddenly introduces NaN, surely I'm not the only one that sees a problem with this ) Especially when it's basically a standard 0 is used for this. Sorry for the rant. Let me explain the why: D default initialization is not designed to replace user-defined initialization, it's rather made to make bugs related to non-initialized variables stable, e.g not UB. The easiest way to get that is to think to references and pointers. A random garbage value pointed by an alloca may work to some point (e.g access to member), if it's set to `null` right after the alloca then you have a stable segfault that always happens at the same time and is easy to debug. Similarly, for floating point numbers the D designers considered that `NaN` was the best choice because FP operations will not wrongly appear valid when starting operations with NaN. With integral types, this system does not work as well, as `0` doesn't create bugs as easily as `null` and `NaN`. The confusion about the real role of default initialization comes from integral types I believe.
Re: Why do immutable variables need reference counting?
On Sunday, 17 April 2022 at 14:14:37 UTC, H. S. Teoh wrote: Not entirely true. See paragraph 3 in: https://dlang.org/spec/unittest.html and 10.24.11.3 in: https://dlang.org/spec/expression.html#assert_expressions T Thanks. Either I missed that the last time I checked or it wasn't there ;) But the interesting question is: does the compiler go out of its way to make that happen or is it just paragraphs written in the spec?
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Monday, 18 April 2022 at 10:26:16 UTC, HuskyNator wrote: On a sidenote, I'm surprised D did not choose 0 as the default floating value. Doesn't almost every language do this? I understand the thinking behind it, but when the type one uses in a template influences the behavior of the code, that seems like a pretty big red flag to me. (Any non-floating type defaults to 0, but using floats/doubles suddenly introduces NaN, surely I'm not the only one that sees a problem with this ) Especially when it's basically a standard 0 is used for this. Sorry for the rant. I agree, it's a hiccup. I have at times intentionally initialized a float as NaN so that I can identify later whether an appropriate value has been assigned, but I've never seen the need to have this be the default behavior when integer types always init to 0 (more specifically, init to a MODIFYABLE value). In game design I have tons upon tons of floats that all [should] start initialized to zero. I can add 4 to a declared but not-assigned-to int and it'll be 4, a float remains NaN. Having to manually declare appropriate init values to each one doesn't aid me in detecting "bugs". If I had an int that was supposed to default to 10 instead of 0 it would still be a bug if I forgot to specify that, tripping me up for falsely assuming floats would start at 0 doesn't aid my workflow in any way. The whole "you should pay more attention to what you're initializing, o buggy programmer you" philosophy seems like something that should be reserved for pointers and reference types, not basic numeric data. It's probably set in stone by this point though and too late to change. Ten years ago, almost to the day: https://forum.dlang.org/thread/thsjtreegdwcgbazh...@forum.dlang.org The reasoning still feels flimsy and stubborn.
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Monday, 18 April 2022 at 03:21:30 UTC, H. S. Teoh wrote: Structs in D ought to be treated like "glorified ints", as Andrei puts it. If you need complex ctors and complex methods, that's a sign you should be using a class instead. I prefer not to use classes, as the code would now move towards using references, which is the exact reason I'm using structs. I ended up creating a constructor for my needs and disabling the default constructor. I'm mostly just surprised the static syntax is turned off by adding one. I still don't see the reason behind it. Why have it but disable it? I ironically almost always need the exact same constructor with the identical arguments though: Initialize the matrix to the identity matrix. Why not introduce the empty self-defined constructor as a separate thing from the .init value? On a sidenote, I'm surprised D did not choose 0 as the default floating value. Doesn't almost every language do this? I understand the thinking behind it, but when the type one uses in a template influences the behavior of the code, that seems like a pretty big red flag to me. (Any non-floating type defaults to 0, but using floats/doubles suddenly introduces NaN, surely I'm not the only one that sees a problem with this ) Especially when it's basically a standard 0 is used for this. Sorry for the rant.
Re: Install D lang on Windows 10 : an installation step by step tutorial made by a beginner who loves D !
On Monday, 18 April 2022 at 08:22:43 UTC, SMAOLAB wrote: I tried to install D on a Windows 10 but encountered some difficulties (even though I was reading the official D langage tutorial available on the official website). What went wrong when you used the DMD installer? Installing Visual Studio should not be necessary, since DMD ships with the lld linker and MinGW Windows import libraries. If it doesn't work out of the box, it should be fixed. Nevertheless, thanks for writing the detailed instructions. Have a nice reading and don't hesitate to send me your comments, I will improve the document... I don't see the guide (explicitly) installing git, but I recall dub needing it to install packages. Is that covered?
Install D lang on Windows 10 : an installation step by step tutorial made by a beginner who loves D !
Hello everyone, I am a newbie in the D langage. I tried to install D on a Windows 10 but encountered some difficulties (even though I was reading the official D langage tutorial available on the official website). I guess that for someone who has a totally new PC, new & fresh Windows 10 operating system, well, installing D, it's not so easy... :-) This is why I decided to publish a tutorial on how to install D lang on a fresh Windows 10 (step by step tutorial). Here is the link to the tutorial: https://p0nce.github.io/d-idioms/#Installing-Dlang-on-Windows I hope that this "simple" document will complete the official D installation tutorial. Have a nice reading and don't hesitate to send me your comments, I will improve the document... Regards
Re: Static struct initialization syntax behavior & it being disabled upon adding a constructor
On Monday, 18 April 2022 at 03:21:30 UTC, H. S. Teoh wrote: Structs in D ought to be treated like "glorified ints", as Andrei puts it. If you need complex ctors and complex methods, that's a sign you should be using a class instead. Unless you're having a nice quiet get-together with friends, and you don't want to invite the GC, the biggest loudest party animal on the block. Phobos's RefCounted seems to stretch the definition of "glorified ints"..
Re: DUB issues
On Monday, 18 April 2022 at 05:27:32 UTC, Danny Arends wrote: Hey All, For some reason I cannot reset my password to get into dub (https://code.dlang.org/), after trying I never receive the email to reset my password. I was unsure at first if I had signed up at all, but trying to make a new account tells me my email address is already in use. Any ideas how to get into contact/fix this issue ? I tried to look around and it seems that there are no direct contacts. There is old inactive forum. https://forum.rejectedsoftware.com/groups/rejectedsoftware.dub/ You can try this general email: i...@rejectedsoftware.com This one is for both vibe.d and dub. If no response, there will be a need to try to contact the dub authors personally about this issue. I think it's kind of frustrating. If there is a need, I can try to annoy them on the social media, maybe they'll turn up.
