Re: Making an .exe that executes source file inside itself.
On Thursday, 26 April 2018 at 06:18:25 UTC, BoQsc wrote: On Wednesday, 25 April 2018 at 20:44:10 UTC, u0_a183 wrote: On Wednesday, 25 April 2018 at 19:54:26 UTC, BoQsc wrote: On Wednesday, 25 April 2018 at 19:43:31 UTC, Jonathan M Davis wrote: On Wednesday, April 25, 2018 19:19:58 BoQsc via Digitalmars-d-learn wrote: So there has been idea I've got for around few months now: making a software which executable would contain a source file. A software that anyone could modify by opening an executable and quickly change a few lines of it, rerun an executable, see the changes. Could this be easily possible with D language, considering that sources files can be ran without long slow compilation process? The normal way to do that is to just write a script. In the case of D, you can just use rdmd to do it. e.g. if you're on a POSIX system, just put #!/usr/bin/env rdmd at the top of your .d file and chmod it so that it's executable, and it'll run like any other script. - Jonathan M Davis Thank you Jonathan for a response. I was aware of this, and it certainly perfectly works where command line/terminal interface is the main tool to control the system, a good example would be linux/gnu distributions and macOS. However in Windows while installing D language, I noticed that .d source file extension is not associated with neither D compiler (dmd.exe) nor D script interpretator (rdmd.exe) So they can't be ran directly by clicking on those, nor they have any icons that show that these source codes are actually executable. This is a huge problem, because people that are not aware of D language migh be harder to understand that source script could be executable, at least - without help from some more experienced user. If the purpose is to make scripts run by clicking them you can assign a file type to .d files. On Windows 10. https://www.digitaltrends.com/computing/how-to-set-default-programs-and-file-types-in-windows-10/ Doing so would make the script engine the default program instead of a text editor so you might not want to. Or maybe assign .dxe and changing the filename before running. Executable has executable file type for a reason - it self-implies that the main function of the file - is to be executed. The problem with making source code files executable is that, source code files, might not always be monolithic executable code, but a part of a bigger interconnected program. That would lead to partily working program execution, and most of the times guess work of whether source code file was supposed to be executed. This is wrong. All code must be included. All library source code is included. If this is infeasible then simply the binaries are included. It would be no different than dynamic linking that already exists. It doesn't create any new problems. Sure certain things would need to be worked out properly to optimize the experience, but that is obvious. One can't make everything perfect though and one shouldn't expect it... The clear alternative would be: .exe file on which, if rightclicked - would open context menu showing posibility of "edit/improve this executable". Which would not create additional problem mentioned above.
Re: readonly member (but assignable at constructor time)
On Friday, April 27, 2018 02:59:16 Dr.No via Digitalmars-d-learn wrote:
> In C# you can have a readonly member assignable either at
> declaration or constructor time, like this:
>
> class C
> {
>readonly myClass mc;
>
>this()
>{
> mc = new myClass();
>}
>
>
>void doSomething()
>{
> mc = new myClass(); // wrong! result in compiler error, mc is
> readonly
>}
> }
>
> Does D have something like this natively or there's a way to do
> so with traits/CTFE at runtime?
D has const, though that has some pretty far-reaching repercussions, since
it means that the object can't be mutated at all, and the only member
functions that can be called on it are const or inout.
If you want to specifically make it so that the object is mutable but the
reference can't be assigned to, then it would have to be protected by a
wrapper struct that @disabled opAssign and then either used alias this or
opDispatch to forward calls to the class reference inside the struct. D's
const is transitive and does not have any form of head-const, so const can't
be used in a case like that.
- Jonathan M Davis
readonly member (but assignable at constructor time)
In C# you can have a readonly member assignable either at
declaration or constructor time, like this:
class C
{
readonly myClass mc;
this()
{
mc = new myClass();
}
void doSomething()
{
mc = new myClass(); // wrong! result in compiler error, mc is
readonly
}
}
Does D have something like this natively or there's a way to do
so with traits/CTFE at runtime?
bitfields comparison in opEquals
I have a struct with a mixin(bitfields) containing many small
bitfields. I also have a class member in the struct.
And because I want the class member to compare by using `is` I
need to define
bool opEquals(const scope typeof(this) that) const @safe pure
nothrow @nogc
{
return (this.data == that.data &&
this.context is that.context &&
// these are all bitfields members
// TODO can we do this comparison in one go?
this.lang == that.lang &&
this.pot == that.pot &&
this.manner == that.manner &&
this.senseNr == that.senseNr &&
this.hasUniquePot == that.hasUniquePot &&
this.isHashed == that.isHashed);
}
Is there a way to make the bitfields-comparsion in opEquals run
faster by somehow checking for its size in words (n) and casting
it to size_t[n] which can be compared very fast.
Re: Arguments of function as an array.
On Thursday, April 26, 2018 21:28:27 Jonathan via Digitalmars-d-learn wrote:
> Is there a way in D to take past arguments as an array? A like a
> normal Variadic function. All the arguments should be of the
> same type just as an array.
>
> Basically I want to allow a function like this to be called
> without square brackets.
>
> void fun(int[] intArray) {
> //...
> }
> void main() {
> fun([5,6,4]);
> }
>
> Like this:
>
> void fun(int... intArray) {
> //typeof(intArray) is `int[]`
> }
> void main() {
> fun(5,6,4);
> }
>
> Is this doable in D?
For better or worse, D has multiple types of variadic functions. Variadic
templated functions are almost certainly the most commonly used, but what
the spec calls "typesafe variadic functions" result in a dynamic array like
what you're talking about:
https://dlang.org/spec/function.html#typesafe_variadic_functions
- Jonathan M Davis
Re: Arguments of function as an array.
On 04/26/2018 11:28 PM, Jonathan wrote:
Is there a way in D to take past arguments as an array? A like a normal
Variadic function. All the arguments should be of the same type just as
an array.
Basically I want to allow a function like this to be called without
square brackets.
void fun(int[] intArray) {
//...
}
void main() {
fun([5,6,4]);
}
Like this:
void fun(int... intArray) {
//typeof(intArray) is `int[]`
}
void main() {
fun(5,6,4);
}
Is this doable in D?
void fun(int[] intArray ...) {}
https://dlang.org/spec/function.html#typesafe_variadic_functions
Note that such an array is not garbage collected. It's a slice of the
stack. Don't return it from the function.
Arguments of function as an array.
Is there a way in D to take past arguments as an array? A like a
normal Variadic function. All the arguments should be of the
same type just as an array.
Basically I want to allow a function like this to be called
without square brackets.
void fun(int[] intArray) {
//...
}
void main() {
fun([5,6,4]);
}
Like this:
void fun(int... intArray) {
//typeof(intArray) is `int[]`
}
void main() {
fun(5,6,4);
}
Is this doable in D?
Idiomatic way to add examples to dub package
Most dub packages are libraries and should provide runnable examples. What's the current idiomatic way to add examples? I used sub-packages with dependency on the library and "*" as version and running them as dub run :examplename Now I've noticed vibed uses a different scheme - examples are like separate packages that are supposed to ran with --root option (if running from the library root directory) and specify the dependency with "path" property like here https://github.com/vibe-d/vibe.d/blob/master/examples/http_server/dub.json That involves more typing when running an example but keeps the main dub.json independent from examples (no need to specify sub-packages) Also I still don't understand if I need to include dub.selections.json in VCS repo. I read somewhere that it should be included but vibed examples don't have dub.selections.json. E.g. here https://github.com/dlang/dub/issues/829#issuecomment-215741874 jacob-carlborg said For applications the dub.selection.json files should be in version control, for libraries it should not be Examples are applications so I thought dub.selections.json should be included. But it may be an outdated information. If there're tutorials on both topics (how to include examples and when one should include dub.selections.json in VCS), I would like to read them. I could not find any useful info on code.dlang.org regarding these issues, while those look like basic issues that must be covered in manuals.
Re: What's wrong with this alias?
On 04/26/2018 10:56 AM, Dr.No wrote:
> class C
> {
>
> void error(A...)(string fmt, A args)
> {
> import report : error;
> reportedAnyError = true;
> error(fmt, args);
> }
> alias warning = report.warning;
> }
>
>
> I got this:
>
> Error: undefined identifier report.warning
If that really is the code, you're forgetting to import report in that
scope. Otherwise, that kind of alias works at least in this simple case:
void foo(A...)(A a) {
import std.stdio;
writeln(a);
}
alias bar = foo;
void main() {
bar(42, "hello");
}
Ali
What's wrong with this alias?
consider this:
module report;
// output an error message on stderr
void error(A...)(string fmt, A args)
{
import colorize : fg, color, cwriteln, cwritefln, cwrite;
stderr.cwrite("error: ".color(fg.yellow));
cwritefln(fmt.color(fg.yellow), args);
}
void warning(A...)(string fmt, A args)
{
import colorize : fg, color, cwriteln, cwritefln, cwrite;
cwrite("warning: ".color(fg.blue));
cwritefln(fmt.color(fg.blue), args);
}
then
class C
{
void error(A...)(string fmt, A args)
{
import report : error;
reportedAnyError = true;
error(fmt, args);
}
alias warning = report.warning;
}
I got this:
Error: undefined identifier report.warning
but this works:
void warning(A...)(string fmt, A args)
{
import report : warning;
warning(fmt, args);
}
why alias cannot find my symbol there?
Re: Get files from directory sorted by name
On Wednesday, 25 April 2018 at 19:25:11 UTC, Jesse Phillips wrote: On Wednesday, 25 April 2018 at 17:34:41 UTC, Dr.No wrote: Is there something implemented already to get the files from directory by name using D or I'm on my own and I have to write it myself? I didn't find how do that with dirEntries() I want to add that sorting can be done, if you just call std.algorithm.sort you'll find that file names with numbers in them will be sorted as a well strings. Newfile1.txt Newfile10.txt Newfile2.txt I've had realized that then implemented natural sort
Re: Get files from directory sorted by name
On Wednesday, 25 April 2018 at 18:06:07 UTC, Jonathan M Davis wrote: On Wednesday, April 25, 2018 17:34:41 Dr.No via Digitalmars-d-learn wrote: Is there something implemented already to get the files from directory by name using D or I'm on my own and I have to write it myself? I didn't find how do that with dirEntries() There is nothing in the standard library for doing it, though maybe someone has something on code.dlang.org. However, the underlying OS API doesn't exactly conform well to that particular use case. AFAIK, given how the C APIs work, the only option is to get the list of files and then sort it, which could be done easily enough with dirEntries. Something as simple as auto files = dirEntries(dir, SpanMode.shallow).array(); sort!((a, b) => a.name < b.name)(files); would give you a sorted DirEntry[] of all of the directories and files directly in the directory. SpanMode.depth or SpanMode.breadth could be used instead if you want sub-directories, and std.algorithm.iteration.filter could be used if you want to do something like filter out directories. std.algorithm.iteration.map could be used if you just want the file names. So, if you wanted just the names, you could do auto files = dirEntries(dir, SpanMode.shallow).map!(a => a.name)().array(); sort(files); though you'd need to use std.path.baseName if you didn't want the full path - e.g. map!(a => a.name.baseName)(). If you wanted just files, you could do something like auto files = dirEntries(dir, SpanMode.shallow). filter!(a => a.isFile()).array(); sort!((a, b) => a.name < b.name)(files); or auto files = dirEntries(dir, SpanMode.shallow). filter!(a => a.isFile()).map!(a => a.name).array(); sort(files); Exactly which combination of functions you use depends on what you want for the end result. But the key thing is that you use std.array.array to convert the forward range into a dynamic array so that std.algorithm.sorting.sort can sort it (since it requires a random-access range). I really don't think that you're going to find any other way to do this other than someone who has written a function that just ends up doing the same thing by wrapping a call to dirEntries or the underlying C API. - Jonathan M Davis I have had just called sort, to later realize the sort wasn't in the way humans expect (which is the way Windows Explorer does) so I eventually reached https://blog.codinghorror.com/sorting-for-humans-natural-sort-order/ but I failed to call StrCmpLogicalW() from core.sys.windows.shlwapi or link on my own: pragma(lib, "Shlwapi.lib") extern(Windows) int StrCmpLogicalW( PCWSTR psz1, PCWSTR psz2 ); but I got links error so I went to implement StrCmpLogicalW() on my own and sorted like this: auto files = dirEntries(inputDir, SpanMode.shallow).array(); // natural sort sort!((a, b) => StrCmpLogical(a, b) < 0)(files); which resulted in the files in same way as Windows Explorer/Natural sort.
Re: Template to retrieve compile-time enum member from run-time enum member?
On Thursday, 26 April 2018 at 16:10:16 UTC, Timoses wrote:
Is it possible to use a template to place the "static foreach"
looping to find the correct enum value into? Like I am trying
in the initial "draft" GetMenum?
As the compiler says, the value of `e` is not known at
compile-time. In order to correctly instantiate the template with
that value, all possible instantiations must be instantiated, and
the correct one chosen by a static foreach, just like you do.
The only step you're missing is the template needs to be
instantiated inside the static foreach, like this:
auto instantiateWith(alias Fn, T)(T x)
if (is(T == enum))
{
import std.traits : EnumMembers;
switch (x)
{
static foreach (e; EnumMembers!T)
case e:
return Fn!e;
default:
assert(false);
}
}
enum menum { A, B, C }
template Temp(menum m)
{
enum Temp = m.stringof;
}
unittest {
menum m = menum.A;
import std.stdio;
assert(instantiateWith!Temp(m) == Temp!(menum.A));
m = menum.B;
assert(instantiateWith!Temp(m) == Temp!(menum.B));
m = menum.C;
assert(instantiateWith!Temp(m) == Temp!(menum.C));
}
--
Simen
Template to retrieve compile-time enum member from run-time enum member?
The following should depict what I'm trying to achieve:
```
import std.stdio;
enum menum { A, B, C }
void main()
{
foo(menum.B);
}
void foo(menum e)
{
// Not possible
// run time variable 'e' in conjunction with template 'Temp'
writeln(Temp!(GetMenum(e)));
}
static int i = 0;
template Temp(menum e)
{
// ... do stuff
shared static this()
{
static if (e == menum.A)
i = 1;
}
import std.meta : Alias;
alias Temp = Alias!i;
}
// Trying to return a compile-time variable with a function...
Not like this...
// I don't see a way to pass in the run-time variable without a
function..
template GetMenum()
{
menum GetMenum(menum e)
{
import std.traits : EnumMembers;
static foreach(mem; EnumMembers!menum)
if (mem == e)
return mem;
return menum.A;
}
}
```
yields: Error: variable e cannot be read at compilte time
However, if I replace foo with
```
void foo(menum e)
{
import std.traits : EnumMembers;
static foreach(mem; EnumMembers!menum)
if (mem == e)
writeln(Temp!(GetMenum(mem)));
}
```
it works..
Is it possible to use a template to place the "static foreach"
looping to find the correct enum value into? Like I am trying in
the initial "draft" GetMenum?
Re: Troubles with template constraints on string and static if
On Thursday, 26 April 2018 at 15:06:49 UTC, sungal wrote:
I have this piece of code and I can't understand why the
`static if` conditionals are always false.
```
import std.digest.sha;
import std.file;
import std.stdio;
void main()
{
auto hash1 = produceHash!string("prova.d");
auto hash2 = produceHash!File(File("./prova.d"));
}
string produceHash(Type)(Type data)
if(is(Type == string) || is(Type == File))
{
string h;
static if(is(Type == File)) {
enforce(data.exists, "File does not exist.");
// Hashing both name and file, to avoid having the same
Hash on empty files
return
toHexString(digest!SHA256(data.byChunk(4096*1024))).dup;
} else static if(is(Type == string)){
return toHexString(digest!SHA256(data)).dup;
}
static assert(false, "Data must be string or file. ");
}
```
```
prova.d(22): Error: static assert "Data must be string or
file. "
prova.d(7):instantiated from here: produceHash!string
```
The static assert is unconditionally evaluated after the static
if/else clause. This leads to a compile time assertion failure.
Add an "else", maybe.
Troubles with template constraints on string and static if
I have this piece of code and I can't understand why the `static
if` conditionals are always false.
```
import std.digest.sha;
import std.file;
import std.stdio;
void main()
{
auto hash1 = produceHash!string("prova.d");
auto hash2 = produceHash!File(File("./prova.d"));
}
string produceHash(Type)(Type data)
if(is(Type == string) || is(Type == File))
{
string h;
static if(is(Type == File)) {
enforce(data.exists, "File does not exist.");
// Hashing both name and file, to avoid having the same
Hash on empty files
return
toHexString(digest!SHA256(data.byChunk(4096*1024))).dup;
} else static if(is(Type == string)){
return toHexString(digest!SHA256(data)).dup;
}
static assert(false, "Data must be string or file. ");
}
```
```
prova.d(22): Error: static assert "Data must be string or file. "
prova.d(7):instantiated from here: produceHash!string
```
Re: Making an .exe that executes source file inside itself.
On Wednesday, 25 April 2018 at 19:19:58 UTC, BoQsc wrote: So there has been idea I've got for around few months now: making a software which executable would contain a source file. A software that anyone could modify by opening an executable and quickly change a few lines of it, rerun an executable, see the changes. Could this be easily possible with D language, considering that sources files can be ran without long slow compilation process? If it makes sense for your project, you could embed a scripting language with LuaD or PyD and rerun the script whenever it changes. Alternatively, I don't know about specifics how to implement it in D, but the key phrase you are looking for is "code hotswap" or "hot loading". It's being popularized right now in gamedev circles, to avoid slow complications of the code. The way to do it is push code into DLLs, then reload the DLL if the change is detected. Of course it's not that simple, because there are some tricky parts around DLL boundaries and you have to reload the entire state, but it is possible. In such case, rather than recompile the entire code, you can just recompile a small subset of functionality to a DLL.
Re: Using an external Assembler with D
On Wednesday, 25 April 2018 at 20:31:46 UTC, solidstate1991 wrote: On Wednesday, 25 April 2018 at 15:25:42 UTC, Stefan Koch wrote: Pass stuff on the stack ;) and use extern (C) functions. Thanks! What about extern (D)? Is there a big chaos in the D ABI under x86? I think the D abi is not actually properly spec'd. But I may be wrong about that.
