Re: std.file: read, readText and UTF-8 decoding

[Uranuz via Digitalmars-d-learn]

OK. Thanks for response. I wish that there it was some API to 
handle it "out of the box". Do I need to write some issue or 
something in order to not forget about this?

Re: std.file: read, readText and UTF-8 decoding

[Uranuz via Digitalmars-d-learn]

Addition:
Current solution to this problemme that I was found is:
So I just check for BOM manually. Get length of bom.sequence and 
remove that count of items from beginning. But I dont' think that 
it's convenient solution, because `who knows` how much else 
issues with UTF could happend. And I don't think that it's 
correct to handle them on the side of users of standart D 
library... I think that should be solution "out of the box". It 
could be not much effective, but it should at least "just work" 
without extra movements...

string[] getGroupsFromFile(string groupFilePath)
{
writeln(`Parse file` ~ groupFilePath);
string[] groupNames = [];
char[] rawContent = cast(char[]) read(groupFilePath);
auto bom = getBOM(cast(ubyte[]) rawContent);
string content = cast(string) rawContent[bom.sequence.length..$];
writeln(`Content:\n` ~ content);

//... work with XML
return groupNames;
}

std.file: read, readText and UTF-8 decoding

[Uranuz via Digitalmars-d-learn]

Hello!
I have some strange problem. I am trying to parse XML files and 
extract some information from it.
I use library dxml for it by Jonathan M Davis. But I have a 
probleme that I have multiple  XML files made by different people 
around the world. Some of these files was created with Byte Order 
Mark, but some of them without BOM. dxml expects no BOM at the 
start of the string.
At first I tried to read file with std.file.readText. Looks like 
it doesn't decode file at any way and doesn't remove BOM, so dxml 
failed to parse it then. This looks strange for me, because I 
expect that "text" function must decode data to UTF-8. Then I 
read that this behavior is documented at least:

"""
...However, no width or endian conversions are performed. So, if 
the width or endianness of the characters in the given file 
differ from the width or endianness of the element type of S, 
then validation will fail.

"""
So it's OK. But I understood that this function "readText" is not 
usefull for me.
So I tried to use plain "read" that returns "void[]". Problemmme 
is that I still don't understand which method I should use to 
convert this to string[] with proper UTF-8 decoding and remove 
BOM and etc.

Could you help me, please to make some clearance.
P.S. Function readText looks odd in std.file, because you cannot 
specify any encoding to decode this file. And logic how it 
decodes is unclear...

Re: Why Throwable.message is not a property

[uranuz via Digitalmars-d-learn]

On Wednesday, 17 March 2021 at 19:38:48 UTC, Adam D. Ruppe wrote:

On Wednesday, 17 March 2021 at 19:32:02 UTC, uranuz wrote:
Seems that a problem with concatenation is because 
Throwable.message has const(char)[] type, but not string. This 
makes some inconvenience ;-)


Yes, that's what I thought.

The concat operation tends to give the most flexible type of 
the arguments... and I wish it would then ACTUALLY use that 
flexibility... but it doesn't.


Regardless though since you know you are concating it, which 
means you get a new string anyway, you can safely cast(string) 
it.


string longMsg = "The: " ~ cast(string) exc.message;

that's how i do it.


This is what I have done ;-)

Re: Why Throwable.message is not a property

[uranuz via Digitalmars-d-learn]

On Wednesday, 17 March 2021 at 17:52:20 UTC, Adam D. Ruppe wrote:

On Wednesday, 17 March 2021 at 17:46:27 UTC, uranuz wrote:
Also because it is not a property in some contexts when I try 
to concatenate it with string without parentheses using "~" 
operator it fails


Can you post some sample code that demonstrates this?


Seems that a problem with concatenation is because 
Throwable.message has const(char)[] type, but not string. This 
makes some inconvenience ;-)


There is an example:

import std;

void main()
{
auto exc = new Exception("Test");
string longMsg = "The: " ~ exc.message; // Adding parentheses 
() after "message" actually doesn't change anything. Error is the 
same

writeln(longMsg);
}

Compile error:

onlineapp.d(6): Error: cannot implicitly convert expression "The: 
" ~ exc.message() of type char[] to string


I could add cast(string), but it's not something I want to do.

The reason, why I want to use "message" instead of "msg" is that 
I want to add some extra information to exception as separate 
typed fields. But I want it to be displayed when converting 
exception to string. So I shall override "message" and convert 
this extra info to string...

Why Throwable.message is not a property

[uranuz via Digitalmars-d-learn]

The question is why Throwable.message is not a @property?! It 
looks strange now, because "message" is not a *verb*, but a 
*noun*. So it's expected to be a property. Also because it is not 
a property in some contexts when I try to concatenate it with 
string without parentheses using "~" operator it fails, because 
(as you could expect) it is a *regular* function, but not a 
property.


I wonder if it was made as *non-property* by some reason or by 
oversight?


Thanks

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

> Either way, generic code should never be using a range after 
> it's been copied, and copying is a key part of how 
> idiomatic, range-based code works in D.


OK. Thanks for instructions. I shall give it a try.

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

On Sunday, 16 February 2020 at 12:38:51 UTC, Jonathan M Davis 
wrote:
On Sunday, February 16, 2020 3:41:31 AM MST uranuz via 
Digitalmars-d-learn wrote:

I have reread presentation:
http://dconf.org/2015/talks/davis.pdf
We declare that `pure` input range cannot be `unpoped` and we
can't return to the previous position of it later at the time. 
So

logically there is no sence of copying input range at all. So
every Phobos algorithm that declares that it's is working with
InputRange must be tested for working with range with disabled
A range that can't be copied is basically useless. Not only do 
almost all range-based algorithms take their argumenst by value 
(and thus copy them), but foreach copies any range that it's 
given, meaning that if a range isn't copyable, you can't even 
use it with foreach. And since many range-based algorithms 
function by wrapping one range with another, the ability to 
copy ranges is fundamental to most range-based code.

This is working fine with disabled postblit...
import std;

struct SS
{
@disable this(this); // Disabled copy

bool _empty = false;

bool empty() @property {
return _empty;
}

void popFront() {
   _empty = true;
}

int front() @property { return 10; }
}


void main()
{
foreach( it; SS() ) { writeln(it); }
}

Am I missing something?

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

In general for value-semantics and ref-semantics the different 
code is actually needed. But generic algorithm try to pretend 
that the logic is the same. But it's not true. But in wide subset 
of trivial algorithm it's true. So it's incorrectly interpolated 
that it's true for every case. The very bad thing if range is 
passed by value it still can have value or reference semantic. 
And algorithm cannot say which is it actually. There is not such 
problemme for classes. So as I already said when passing ranges 
by ref in algorithms they behave predictible. And if I want 
algrorithm to operate on copy of algorithm then I can just create 
this copy before passing it to this algorithm. And again 
intention is more clear. But Phobos algorithms don't work like 
that. It's why I can't use them in some cases, because they are 
looking unpredictable for me.

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

It's very bad. Because there seem that when I use range based 
algorithm I need to take two things into account. The first is 
how algrorithm is implemented. If it creates copies of range 
inside or pass it by reference. And the second is how the range 
is implemented if it has value or reference semantics. So every 
time I need to look into implementation and I can't rely on API 
description in most of the cases. In a lot of cases Phobos uses 
value semantics. But there are cases where I want the range 
actually be consumed, but it's not. And the other problemme is 
when algorithm expects range to have value semantics, but it's 
not. So it's a buggy mess that it's hard to think about. In 
trivial cases this is working although. But in more complex cases 
it's simplier to implement some algorithms by own hands so that 
it would work as I expect it myself rather that thinking about 
all these value-ref-range mess. But still can't say that I 
implement it correctly, because range specification actually 
sucks as yo say.

It's just horrible

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

I have reread presentation:
http://dconf.org/2015/talks/davis.pdf
We declare that `pure` input range cannot be `unpoped` and we 
can't return to the previous position of it later at the time. So 
logically there is no sence of copying input range at all. So 
every Phobos algorithm that declares that it's is working with 
InputRange must be tested for working with range with disabled 
copy constructor and postblit. And if it is not it means that 
this algroithm actually requires a forward range and there we 
missing `save` calls?
Because as it was written in this presentation a range copy is 
undefined (without call to save). So it's illegal to create copy 
of range in Phobos algorithms without `save`?
So we need a test for every algorithm that it is working with 
range with disabled copy constructor and postblit if we declare 
that we only use `save` for range copy?

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

Also I see the problemme that someone can think that it creates 
an input range, because he doesn't provide `save` method, but 
actually it creates forward range unexpectedly, because it is 
copyable. And it makes what is actually happening in code more 
difficult. Some algrorithm can take ranges by value, but others 
take them by reference. So result can be completely different. In 
first case range is being consumed, but in another in is not. 
Personally I prefer to take range by reference in all of my 
algrorithms except cases where I is always a class (because it's 
a reference already). But I still don't know what is the right 
way. There are no official guidelines about it. So every time 
it's a problemme. Although it looks like that range is a simple 
concept, but it's actually not.

Re: Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

Actually, as I understand it, the main reason that save was 
introduced was so that classes could be forward ranges


I have use of ranges as a classes in my code that rely on classes 
and polymorthism, but it's usually an InputRange that implements 
Phobos interface:

https://dlang.org/phobos/std_range_interfaces.html#.InputRange

I have virtual opSlice operator that returns InputRange. And 
sometimes implementation of range is very different. So it's 
difficult to write one range as a struct. I have a pattern in my 
code that looks like the following:


interface IContainer
{
   InputRange opSlice();
}

class MyContainer1: IContainer
{
   class Range1: InputRange {
  //... one implementation
   }
   override InputRange opSlice() {
   return new Range1(this);
   }
}

class MyContainer2: IContainer
{
   class Range2: InputRange {
  //... another implementation
   }
   override InputRange opSlice() {
   return new Range2(this);
   }
}

In this example I need a range to be a class, but not a struct.

Another problemme is that `copy contructor` is defined only for 
structs, but not classes. For the class that uses another class 
instance of the `same` type to initialize from it would be a 
regular constructor with parameter.
A copy constructor in struct semantics requires that the source 
would be actually `the same` type. But for classes source could 
be instance of another class that is inherited from current 
class. And we cannot prove statically that it's actually the same 
type.
And also if we talk about range interface constructor cannot be a 
part of it. So we cannot add `copy contructor` (if we would have 
it for class) to interface and check for it's presence in generic 
code. So here we have this workaround with `save` method...
I don't like that primitive concept has two ways to do the same 
thing. And it's unclear what is the primary way of doing this 
(copy constructor or save). It introduce the situation when half 
of the code would require range being copyable, but another part 
would require it to to have a save method. Not the situation is 
that there are a lot of algorothms in Phobos that are not working 
with ranges that have disabled postblit, but have `save` method 
that could be used to make a copy.

Still I want to be able to create ranges as classes...

Difference between range `save` and copy constructor

[uranuz via Digitalmars-d-learn]

I am interested in current circumstances when we have new copy 
constructor feature what is the purpose of having range `save` 
primitive? For me they look like doing basicaly the same thing. 
And when looking in some source code of `range` module the most 
common thing that `save` does is that it use constructor 
typeof(this) to create a new instance and use `save` on the 
source range:

https://github.com/dlang/phobos/blob/v2.090.1/std/range/package.d

So what is conceptual difference between `save` and copy 
contructor of range?

Re: D create many thread

[uranuz via Digitalmars-d-learn]

Is it also possible to set some custom thread name for GC threads 
in order to be distinguishable from other threads in utilities 
like `htop`? It would be handy...

Re: Question about alias and getOverloads

[uranuz via Digitalmars-d-learn]

OK. Thanks. Created two reports related to these questions:
https://issues.dlang.org/show_bug.cgi?id=20553
https://issues.dlang.org/show_bug.cgi?id=20555

Re: Question about alias and getOverloads

[uranuz via Digitalmars-d-learn]

I apologise that I need to revive this discussion again. But 
still I got answer to only one of my questions. I know that it is 
a common practice in programmers society that when someone asks 
more than 1 question. Then people who answer them usually choose 
only one of these questions that is the most easiest to answer. 
But the rest of the questions are just ignored. But the topic is 
still considered resolved. Person who answered `increased his 
carma`. All are happy. Except for the man who asked the question, 
but only got answer that is trivial, easy-to-answer or 
easy-to-find by himself. And actually got the answer to only one 
of the questions. And it is the less important.


At my job in this case I usually ask questions only one by one. 
It gives to person that shall try to answer no options and to 
answer only to this question. So only when I got answer that 
satisfies me I start to ask the next question.
I didn't want to use this technique there, because I believe that 
D community is better...


Sorry for this disgression, but I still don't understand several 
main points:
1. Why API for __traits(getOverloads) is so strange. Why I need 
to find parent for symbol myself and pass actual symbol name as 
string, but not actually pass a symbol itself? It is very strange 
to me...
2. Where in the documentation is mentioned that when I create 
alias to name that is a function or method that has overloads 
then this alias is actually an alias not only for the first or 
second or randomly selected overload in overload set, but an 
alias for all of overloads in set at the same time?


Thanks. Have a good day!

Re: Question about alias and getOverloads

[uranuz via Digitalmars-d-learn]

I have read it two or three times just before writing my question:
https://dlang.org/spec/declaration.html#alias
And also a have read all the dlang docs several time few years 
ago... ;)
But I don't see what do you you mean by writing that it was 
menioned here. I don't se any words or any examples that describe 
how `alias` works with function overload sets. Is it a blind 
assumption that it was written here?


The only example that someone can mix up and consider as answer 
to my question if actually didn't read it with attention. It is 
example bellow:

```
alias myint = int;

void foo(int x) { ... }
void foo(myint m) { ... } // error, multiply defined function foo
```
But the only thing that this example illustrates is that `myint` 
and `int` is actualy the same  type. So this overload set is just 
incorrect. I don't ask you to consider the case where overload 
set is incorrect. So this didn't answered my question in any way.


Looks like this is some kind of nasty details that language 
developers don't "proud of" and don't like to discover details 
about how it's working. Or just lazy enough to do so ;)


Still I figured answer myself using your example. The answer is 
not full, but yet enough for me for practical usage. But the lack 
of description about it makes me think that I am not the last man 
who will have his curiosity not fully satisfied about this aspect 
of language.


And also __traits(parent, Func) seems like not universal for all 
cases with functions, because it fails on lambda-functions. For 
instance:

//
import std;

template Bar(alias Func) {
alias Bar = __traits(getOverloads, __traits(parent, Func), 
__traits(identifier, Func));

}

void main()
{
alias Test = Bar!(() { return `test`; });
}
//
Output:
onlineapp.d(4): Error: no property __lambda1 for type void
onlineapp.d(4): Error: main().__lambda1 cannot be resolved
onlineapp.d(9): Error: template instance onlineapp.Bar!(function 
() pure nothrow @nogc @safe => "test") error instantiating

//
Seems that it fails to get parent for lambda. I don't know why? 
What parent should be for labmda?


Thanks for attention!

Re: Question about alias and getOverloads

[uranuz via Digitalmars-d-learn]

Thanks for advice ;) This looks like some `standard trick` that 
is yet not learnt or forgoten by me personally. The key was in 
using `parent` trait. This is what I failed to think of. This is 
working as expected:

//-
import std;
import core.thread;
import std.meta: AliasSeq;

void foo(string param1) {}
void foo(string param1, int param2, bool param3) {}

template Bar(alias Func)
{
alias Bar = __traits(getOverloads, __traits(parent, Func), 
__traits(identifier, Func));

}

void main()
{
import std.traits: fullyQualifiedName, Parameters;
import std.conv: text;
static foreach( It; Bar!foo ) {
	pragma(msg, fullyQualifiedName!It ~ "/" ~ 
(Parameters!It).length.text);

}
}
//-
Output:
onlineapp.foo/1
onlineapp.foo/3
//-

So as far as I understand alias template parameter gives access 
to all of items of overload set as I was expecting. The only 
problem is that I didn't found something about it in 
specification about templates:

https://dlang.org/spec/template.html

Question about alias and getOverloads

[uranuz via Digitalmars-d-learn]

Hello! I have a question about `alias` template parameter and 
getOverloads.

For instance I have some code like this:
// -
import std;
import core.thread;

void foo(string param1) {}
void foo(string param1, int param2) {}

template Bar(alias Func)
{
// Next line is not valid now. This is my understanding of 
how I wish it would work...

pragma(msg, __traits(getOverloads, Func));
}

void main()
{
Bar!foo;
}
//---
By the spec:
https://dlang.org/spec/traits.html#getOverloads
The signature of `getOverloads` trait requires me to pass a 
symbol where my function is contained (it could be class, struct 
or module). And a name of function that I want to get overloads 
for.


Let's imagine that `foo` overloads and Bar template are in 
different modules. And `Bar` template doesn't have no direct 
access to module where `foo` is contained. And `Bar` is 
instantiated outside module where `Bar` is declared.


I have two questions:
1. Whether `Bar` instantiation would get first, second or both 
overloads of function? Or maybe I would get two instantiations of 
template by the number of overloads? I don't understand well how 
this mechanic is working. Is it documented somewhere? Does 
actually one alias parameter represents only one symbol from 
overload set or all of them?


2. If alias parameter represents multiple symbols from overload 
set. Then I wish I could access to list of overloads having alias 
parameter. I wish to get count of overloads in my real case in 
order to issue an error that overloaded are not supported by my 
code.

Re: Some code that compiles but shouldn't

[uranuz via Digitalmars-d-learn]

On Monday, 30 December 2019 at 19:09:13 UTC, MoonlightSentinel 
wrote:

On Monday, 30 December 2019 at 18:18:49 UTC, uranuz wrote:
So as you see I have added a lot of enforce to test if all 
variables are not null. But nothing was null and the reason of 
segfault were unclear.


What about moduleName, mod and the return value of 
mod.toStdJSON()?


And whats the return type of ctx.response.write? (Returning a 
void expression is allowed and avoids some special casing in 
generic code)


OK. This example compiles...

void bar() {}

void main()
{
return bar();
}

Re: Some code that compiles but shouldn't

[uranuz via Digitalmars-d-learn]

On Monday, 30 December 2019 at 19:09:13 UTC, MoonlightSentinel 
wrote:

On Monday, 30 December 2019 at 18:18:49 UTC, uranuz wrote:
So as you see I have added a lot of enforce to test if all 
variables are not null. But nothing was null and the reason of 
segfault were unclear.


What about moduleName, mod and the return value of 
mod.toStdJSON()?


And whats the return type of ctx.response.write? (Returning a 
void expression is allowed and avoids some special casing in 
generic code)


I have reviewed this code and ctx.response.write(...) returns 
void too.. ;-)
So I don't even know if this is correct or no? Could I use 
`return void;`?

Some code that compiles but shouldn't

[uranuz via Digitalmars-d-learn]

I have created library/ framework to handle JSON-RPC requests 
using D methods. I use some *template magic* to translate 
JSON-RPC parameters and return values from/ and to JSON. And I 
have encountered funny bug that at first was hard to find. My 
programme just segfaulted when call to this method occured:


void getCompiledTemplate(HTTPContext ctx)
{
import std.exception: enforce;
enforce(ctx, `ctx is null`);
enforce(ctx.request, `ctx.request is null`);
enforce(ctx.request.form, `ctx.request is null`);
enforce(ivyEngine !is null, `ivyEngine is null`);
string moduleName = ctx.request.form[`moduleName`];
auto mod = ivyEngine.getByModuleName(moduleName);
return ctx.response.write(mod.toStdJSON().toString());
}


So as you see I have added a lot of enforce to test if all 
variables are not null. But nothing was null and the reason of 
segfault were unclear.
Today I just went home. Opened a bottle of beer. And have noticed 
that function is marked as returning `void`, but in fact it 
doesn't. When I fixed this segfault have gone. But why this even 
compiled?! Interesting...

Re: How to make rsplit (like in Python) in D

[Uranuz via Digitalmars-d-learn]

On Saturday, 1 October 2016 at 18:33:02 UTC, TheFlyingFiddle 
wrote:

On Saturday, 1 October 2016 at 16:45:11 UTC, Uranuz wrote:

[...]


There are two reasons why this does not compile. The first has 
to do with how retro() (and indeed most function in std.range) 
work with utf-8 strings (eg the string type). When working on 
strings as ranges, the ranges internally change the type of 
".front" from 'char' into 'dchar'. This is done to ensure that 
algorithms working on strings do not violate utf-8.


[...]


Thanks for clarification. It seems that once upon a time I'll 
write my own string wrapper that will return just slice of 
`string` pointing to source multibyte sequence as .front and will 
use it, and be happy. When I looking more at other languages 
(like Python) then I more convinced that working with UTF-8 
string as array of single bytes is not very good

Re: How to make rsplit (like in Python) in D

[Uranuz via Digitalmars-d-learn]

On Saturday, 1 October 2016 at 18:55:54 UTC, pineapple wrote:

On Saturday, 1 October 2016 at 17:55:08 UTC, Uranuz wrote:

On Saturday, 1 October 2016 at 17:32:59 UTC, Uranuz wrote:

On Saturday, 1 October 2016 at 17:23:16 UTC, Uranuz wrote:

[...]


But these example fails. Oops. Looks like a bug(

import std.stdio;
import std.algorithm;
import std.range;
import std.string;

[...]


I created bug report on this:
https://issues.dlang.org/show_bug.cgi?id=16569


This isn't a bug. It's illegal to access the front or back of 
an empty range. (If anything is a bug, it's the 
nondescriptiveness of the error.) You should write this instead:


void main()
{
string str = "";
auto split = str.splitter('.');
if(!split.empty) writeln(split.back);
}


When I pass empty string to splitter in most of languages I 
expect to get list with 1 item (empty string) as a result, but I 
get error instead. And I see inconsistency in that .front behaves 
normally, but .back is not. Usually I access front of range 
directly without any check when I expect it to have exactly 1 
item. But in this case it not working and is very strange.

Re: How to make rsplit (like in Python) in D

[Uranuz via Digitalmars-d-learn]

On Saturday, 1 October 2016 at 17:32:59 UTC, Uranuz wrote:

On Saturday, 1 October 2016 at 17:23:16 UTC, Uranuz wrote:

[...]


But these example fails. Oops. Looks like a bug(

import std.stdio;
import std.algorithm;
import std.range;
import std.string;

[...]


I created bug report on this:
https://issues.dlang.org/show_bug.cgi?id=16569

Re: How to make rsplit (like in Python) in D

[Uranuz via Digitalmars-d-learn]

On Saturday, 1 October 2016 at 17:23:16 UTC, Uranuz wrote:

On Saturday, 1 October 2016 at 16:45:11 UTC, Uranuz wrote:
How to make rsplit (like in Python) in D without need for 
extra allocation using standard library? And why there is no 
algorithms (or parameter in existing algorithms) to process 
range from the back. Is `back` and `popBack` somehow worse 
than `front` and `popFront`.


I've tried to write somethig that would work without 
allocation, but failed.

I have searching in forum. Found this thread:
https://forum.dlang.org/post/bug-1030...@http.d.puremagic.com%2Fissues%2F

I tried to use `findSplitBefore` with `retro`, but it doesn't 
compile:


import std.stdio;
import std.algorithm;
import std.range;
import std.string;

void main()
{
string str = "Human.Engineer.Programmer.DProgrammer";

writeln( findSplitBefore(retro(str), ".")[0].retro );
}

Compilation output:
/d153/f534.d(10): Error: template std.range.retro cannot 
deduce function from argument types !()(Result), candidates 
are:
/opt/compilers/dmd2/include/std/range/package.d(198):
std.range.retro(Range)(Range r) if 
(isBidirectionalRange!(Unqual!Range))



Why I have to write such strange things to do enough 
wide-spread operation. I using Python at the job and there is 
very much cases when I use rsplit. So it's very strange to me 
that D library has a lot of `advanced` algorithms that are not 
very commonly used, but there is no rsplit.


Maybe I missing something, so please give me some advice)


Sorry for noise. It was easy enough:

import std.stdio;
import std.algorithm;
import std.range;
import std.string;

void main()
{
string str = "Human.Engineer.Programmer.DProgrammer";

writeln( splitter(str, '.').back );
}


But I still interested why the above not compiles and how to do 
`rfind` or indexOf from the right in D. I think even if we do 
not have exactly algorithms with these names we could provide 
some examples how to *emulate* behaviour of standard functions 
from other popular languages)


But these example fails. Oops. Looks like a bug(

import std.stdio;
import std.algorithm;
import std.range;
import std.string;

void main()
{
string str = "";

writeln( splitter(str, '.').back );
}

core.exception.AssertError@std/algorithm/iteration.d(3132): 
Assertion failure


??:? _d_assert [0x43dd1f]
??:? void std.algorithm.iteration.__assert(int) [0x4432b0]
??:? pure @property @safe immutable(char)[] 
std.algorithm.iteration.splitter!("a == b", immutable(char)[], 
char).splitter(immutable(char)[], char).Result.back() [0x43b8d6]

??:? _Dmain [0x43ae41]
??:? 
_D2rt6dmain211_d_run_mainUiPPaPUAAaZiZ6runAllMFZ9__lambda1MFZv 
[0x43e33e]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).tryExec(scope void delegate()) [0x43e288]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).runAll() [0x43e2fa]
??:? void rt.dmain2._d_run_main(int, char**, extern (C) int 
function(char[][])*).tryExec(scope void delegate()) [0x43e288]

??:? _d_run_main [0x43e1f9]
??:? main [0x43d049]

Re: How to make rsplit (like in Python) in D

[Uranuz via Digitalmars-d-learn]

On Saturday, 1 October 2016 at 16:45:11 UTC, Uranuz wrote:
How to make rsplit (like in Python) in D without need for extra 
allocation using standard library? And why there is no 
algorithms (or parameter in existing algorithms) to process 
range from the back. Is `back` and `popBack` somehow worse than 
`front` and `popFront`.


I've tried to write somethig that would work without 
allocation, but failed.

I have searching in forum. Found this thread:
https://forum.dlang.org/post/bug-1030...@http.d.puremagic.com%2Fissues%2F

I tried to use `findSplitBefore` with `retro`, but it doesn't 
compile:


import std.stdio;
import std.algorithm;
import std.range;
import std.string;

void main()
{
string str = "Human.Engineer.Programmer.DProgrammer";

writeln( findSplitBefore(retro(str), ".")[0].retro );
}

Compilation output:
/d153/f534.d(10): Error: template std.range.retro cannot deduce 
function from argument types !()(Result), candidates are:
/opt/compilers/dmd2/include/std/range/package.d(198):
std.range.retro(Range)(Range r) if 
(isBidirectionalRange!(Unqual!Range))



Why I have to write such strange things to do enough 
wide-spread operation. I using Python at the job and there is 
very much cases when I use rsplit. So it's very strange to me 
that D library has a lot of `advanced` algorithms that are not 
very commonly used, but there is no rsplit.


Maybe I missing something, so please give me some advice)


Sorry for noise. It was easy enough:

import std.stdio;
import std.algorithm;
import std.range;
import std.string;

void main()
{
string str = "Human.Engineer.Programmer.DProgrammer";

writeln( splitter(str, '.').back );
}


But I still interested why the above not compiles and how to do 
`rfind` or indexOf from the right in D. I think even if we do not 
have exactly algorithms with these names we could provide some 
examples how to *emulate* behaviour of standard functions from 
other popular languages)

How to make rsplit (like in Python) in D

[Uranuz via Digitalmars-d-learn]

How to make rsplit (like in Python) in D without need for extra 
allocation using standard library? And why there is no algorithms 
(or parameter in existing algorithms) to process range from the 
back. Is `back` and `popBack` somehow worse than `front` and 
`popFront`.


I've tried to write somethig that would work without allocation, 
but failed.

I have searching in forum. Found this thread:
https://forum.dlang.org/post/bug-1030...@http.d.puremagic.com%2Fissues%2F

I tried to use `findSplitBefore` with `retro`, but it doesn't 
compile:


import std.stdio;
import std.algorithm;
import std.range;
import std.string;

void main()
{
string str = "Human.Engineer.Programmer.DProgrammer";

writeln( findSplitBefore(retro(str), ".")[0].retro );
}

Compilation output:
/d153/f534.d(10): Error: template std.range.retro cannot deduce 
function from argument types !()(Result), candidates are:
/opt/compilers/dmd2/include/std/range/package.d(198):
std.range.retro(Range)(Range r) if 
(isBidirectionalRange!(Unqual!Range))



Why I have to write such strange things to do enough wide-spread 
operation. I using Python at the job and there is very much cases 
when I use rsplit. So it's very strange to me that D library has 
a lot of `advanced` algorithms that are not very commonly used, 
but there is no rsplit.


Maybe I missing something, so please give me some advice)

Re: How to check member function for being @disable?

[Uranuz via Digitalmars-d-learn]

On Tuesday, 13 September 2016 at 15:32:57 UTC, Jonathan M Davis 
wrote:
On Tuesday, September 13, 2016 08:28:10 Jonathan M Davis via 
Digitalmars-d- learn wrote:
On Tuesday, September 13, 2016 04:58:38 Uranuz via 
Digitalmars-d-learn

wrote:
> In my code I iterate in CT over class methods marked as 
> @property and I have a probleme that one of methods is 
> @disable. So I just want to skip @disable members. I found 
> possible solution, but it's interesting to we if we have 
> more clear and obvious way to test for @disable without 
> using __traits( compile ) for it? @disable "looks" like 
> attribute but seems that I cant't get it through __traits( 
> getAttributes ) or __traits( getFunctionAttributes ). Maybe 
> we could add something to test for @disable if it's not 
> already exists?


I really don't think that it's going to scale properly to 
check whether something is marked with @disable. The problem 
is that it propagates. For instance, if a struct has a member 
variable that has default initialization disabled via @disable 
this(); then that struct effectively has @disable this(); too 
even though it doesn't have it explicitly. So, ultimately what 
needs to be tested for is the behavior and not the presence of 
@disable, and that means testing with __traits(compiles, ...). 
And I would point out that most traits test via 
__traits(compiles, ...) or is(typeof(...)) rather than 
checking for something like an attribute. So, if don't like 
using __traits(compiles, ...) in metaprogramming, your going 
to get frustrated quickly. A large portion of the time, it's 
exactly the solution to the problem.


What would make sense would be creating a trait to test for the 
@disabled functionality in queston - e.g. there could be an 
eponymous template named something like hasDefaultInitializer 
(though that name is a bit long) which indicated whether a type 
had @disabled this(); or not. Then you can use that trait in 
your code rather than using __traits(compiles, ...) all over 
the place.


- Jonthan M Davis


OK. Seems that there is nothing that I could do more about my 
example code.. So the best way to be sure if something is 
assignable property is to try assign to it and test whether it 
compiles. The question was because utill this moment I somehow 
was living without __traits(compiles..). Seems that my use cases 
just was not enough complicated... Thanks for the answers.


It could be good idea to have __traits( isDisable ... ) or 
something for it. I admit that not only '@disabled this();' 
regular methods could me marked @disable too..

How to check member function for being @disable?

[Uranuz via Digitalmars-d-learn]

In my code I iterate in CT over class methods marked as @property 
and I have a probleme that one of methods is @disable. So I just 
want to skip @disable members. I found possible solution, but 
it's interesting to we if we have more clear and obvious way to 
test for @disable without using __traits( compile ) for it? 
@disable "looks" like attribute but seems that I cant't get it 
through __traits( getAttributes ) or __traits( 
getFunctionAttributes ). Maybe we could add something to test for 
@disable if it's not already exists?


void fillProperties(Ctrl)(Ctrl ctrl, IDirectiveStatement 
statement, Interpreter interp)

{
import std.meta: Alias, AliasSeq;
import std.traits;
import std.conv;

	TDataNode[string] attrDict = getNamedAttributesValues(statement, 
interp);


	foreach(  memberName; AliasSeq!( __traits( allMembers, Ctrl ) )  
)

{
		static if(  __traits( compiles, __traits(getOverloads, 
Ctrl.init, memberName) )  )

{
			alias Overloads = AliasSeq!(__traits( getOverloads, Ctrl.init, 
memberName ));

foreach( overload; Overloads )
{

static if( (functionAttributes!(overload) & 
FunctionAttribute.property) )

{

alias params = Parameters!(overload);
static if( params.length == 1 )
{

alias propType = params[0];
		static if( __traits(compiles, mixin("{ ctrl."~memberName~" 
= propType.init; }") ) )

{
pragma( msg, memberName, ":  
",  typeof() );
			TDataNode attrValue = attrDict.get( memberName, 
TDataNode(null) );

if( !attrValue.empty ) {
mixin( "ctrl." ~ memberName ~ " = 
nodeToDValue!(propType)(attrValue);" );

}
}
}
}
}
}
}
}

Re: static immutable and lambdas inside struct or class. Is that bug or not?

[Uranuz via Digitalmars-d-learn]

On Sunday, 14 August 2016 at 15:53:21 UTC, ag0aep6g wrote:

On 08/14/2016 04:27 PM, Uranuz wrote:

[...]


Looks like a compiler bug, since it works without the struct:


import std.algorithm: map;
import std.array: array;
import std.typecons: tuple;


immutable aaa = [
tuple("1", "one"),
tuple("2", "two"),
tuple("3", "three")
];

immutable bbb = aaa.map!( a => a[0] ).array;


And that's essentially the same thing.

It has already been filed:
https://issues.dlang.org/show_bug.cgi?id=15908

For a workaround, it works when you explicitly state the type 
of the parameter:



struct A
{
import std.algorithm: map;
import std.array: array;
import std.typecons: tuple, Tuple;


static immutable aaa = [
tuple("1", "one"),
tuple("2", "two"),
tuple("3", "three")
];

alias Tup = Tuple!(string, string);
static immutable bbb = aaa.map!( (Tup a) => a[0] ).array;
}



OK. I just declared alias for predicate outside struct to 
workaround. Maybe compiler trying to get context when attemting 
to infer arguments for some reason, but fails. Or something 
else...

static immutable and lambdas inside struct or class. Is that bug or not?

[Uranuz via Digitalmars-d-learn]

Greatings!
I need help with these lines bellow. I don't understand why it 
doesn't compile. Is it bug somewhere in Phobos or compiler? Or 
just I wrote smth wrong?

//-
struct A
{
import std.algorithm: map;
import std.array: array;
import std.typecons: tuple;


static immutable aaa = [
tuple("1", "one"),
tuple("2", "two"),
tuple("3", "three")
];

static immutable bbb = aaa.map!( a => a[0] ).array;

}

void main()
{
A a = A();
}

//-

Compilation output:
/opt/compilers/dmd2/include/std/algorithm/iteration.d(455): 
Error: this.__lambda6 has no value


You could test it here: https://dpaste.dzfl.pl/67a8cda8f2a8

Problem with circular imports of modules with static ctors an immutable variables

[Uranuz via Digitalmars-d-learn]

In my program I have error with circular imports of modules with 
static ctors. So I decided to move ctors in separate file and 
import it only from the 1st file. But problem is that in the 
first file I have immutables that should be initialized in shared 
static ctor. However doing it from another module's ctor gives 
compilation error: "Error: cannot modify immutable expression".

1. Is it a bug?
2. Could I solve this problem another way?

Example code:

module mod;

import mod_init;

static immutable string[string] aa;

...

--
module mod_init;

import mod;

shared static this
{
   aa = [ "a": "b", "c": "d" ]; //This gives compilation error
}

...

Re: Stupid question about AA. The following code works but I don't undrstand why?!

[Uranuz via Digitalmars-d-learn]

On Saturday, 9 April 2016 at 21:16:08 UTC, ag0aep6g wrote:

On Saturday, 9 April 2016 at 19:31:31 UTC, Uranuz wrote:
I think that we need to add warning about such case in 
documentation section:

https://dlang.org/spec/hash-map.html#construction_and_ref_semantic

in order to prevent this kind of mistakes in code.


Isn't that exactly what the section you linked does?


Yes certainly. But maybe we should give just a little more 
example there.

Re: Stupid question about AA. The following code works but I don't undrstand why?!

[Uranuz via Digitalmars-d-learn]

On Saturday, 9 April 2016 at 19:25:32 UTC, Uranuz wrote:

On Saturday, 9 April 2016 at 18:27:11 UTC, ag0aep6g wrote:

[...]


Another observation is illustrated with the foloving code:
http://dpaste.dzfl.pl/8d68fd5922b7

Because AA and arrays are not created before they were assigned 
some value it leads to inconsistency in behavior. And will 
produce unexpected and hidden bugs that is not good. It's not 
very good side of D's array and AA. But classes could be also 
affected by this *feature* (or bug, as you wish). So we must 
always construct reference semantics types before passing them 
to functions that will modify it. For classes it's obvious but 
for AA and dynamic arrays is not.


Another solution is to pass reference types by *ref*. So you 
will not have such bugs in implementation


I think that we need to add warning about such case in 
documentation section:

https://dlang.org/spec/hash-map.html#construction_and_ref_semantic

in order to prevent this kind of mistakes in code.

Re: Stupid question about AA. The following code works but I don't undrstand why?!

[Uranuz via Digitalmars-d-learn]

On Saturday, 9 April 2016 at 18:27:11 UTC, ag0aep6g wrote:

On Saturday, 9 April 2016 at 18:06:52 UTC, Uranuz wrote:
Thanks. It's clear now. AA holds not `array struct` itself 
inside, but pointer to it.


How the array is stored in the AA doesn't matter, as far as I 
can see. The point is that you obtain a pointer to the array 
struct in the AA, not a copy.


If you had tried it like the following, mapElem would be a copy 
of the array struct in the AA, and the append would not affect 
mapka["item"]:


string[] mapElem = "item" in mapka ? mapka["item"] : 
(mapka["item"] = []);

mapElem ~= ["dog", "cat", "horse", "penguin", "fish", "frog"];


So reallocation affects ptr to allocated memory but not 
pointer to `array struct`. I think that's it.


Correct.


Another observation is illustrated with the foloving code:
http://dpaste.dzfl.pl/8d68fd5922b7

Because AA and arrays are not created before they were assigned 
some value it leads to inconsistency in behavior. And will 
produce unexpected and hidden bugs that is not good. It's not 
very good side of D's array and AA. But classes could be also 
affected by this *feature* (or bug, as you wish). So we must 
always construct reference semantics types before passing them to 
functions that will modify it. For classes it's obvious but for 
AA and dynamic arrays is not.


Another solution is to pass reference types by *ref*. So you will 
not have such bugs in implementation

Re: Stupid question about AA. The following code works but I don't undrstand why?!

[Uranuz via Digitalmars-d-learn]

On Saturday, 9 April 2016 at 16:44:06 UTC, ag0aep6g wrote:

On 09.04.2016 18:13, Uranuz wrote:

http://dpaste.dzfl.pl/523781df67ab


For reference, the code:

import std.stdio;

void main()
{
string[][string] mapka;

string[]* mapElem = "item" in mapka; //Checking if I have item

if( !mapElem )
		mapElem = &( mapka["item"] = [] ); //Creating empty element 
inside map


writeln( (*mapElem).capacity );

	//Appending should reallocate, so pointer to array should 
change

*mapElem ~= ["dog", "cat", "horse", "penguin", "fish", "frog"];

//But AA still somehow knows the right pointer
writeln(mapka);

//It works, but I dont understand why?
}


mapElem is not a pointer to the elements of the array. It's a 
pointer to the dynamic array structure which holds the pointer 
to the data and the length. That means, the reallocation 
doesn't change mapElem. It changes (*mapElem).ptr.


Thanks. It's clear now. AA holds not `array struct` itself 
inside, but pointer to it. So reallocation affects ptr to 
allocated memory but not pointer to `array struct`. I think 
that's it.

Stupid question about AA. The following code works but I don't undrstand why?!

[Uranuz via Digitalmars-d-learn]

I am stupid today :) So I have a question. The piece of code 
given:


http://dpaste.dzfl.pl/523781df67ab

It looks good, but I don't understand why it works?

Need some help about error that I don't understand

[Uranuz via Digitalmars-d-learn]

In my custom multithreaded web-server (non vibe-based) I got 
error that is strange for me. I've was looking for a reason 
running app under GDB, but I don't understand how to interpret 
what I've got.


It's interesting that it fails (without any error or segfault 
message) in the case when null reference to class object passed 
into static method of class. When it's not null all goes well. So 
there is backtrace:


//---
(gdb) thread apply all bt

Thread 4 (Thread 0x71cb1700 (LWP 30869)):
#0  sem_wait () at 
../nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S:85

#1  0x0084747f in core.thread.suspend() ()
#2  0x00839467 in thread_suspendAll ()
#3  0x0082bd88 in gc.gc.Gcx.fullcollect() ()
#4  0x0082a43d in gc.gc.Gcx.bigAlloc() ()
#5  0x00827ca5 in gc.gc.GC.malloc() ()
#6  0x007f36cc in gc_malloc ()
#7  0x007f09f0 in core.memory.GC.malloc() ()
#8  0x008321cf in 
std.array.__T14arrayAllocImplVbi0TAhTmZ.arrayAllocImpl() ()
#9  0x008321a1 in 
std.array.__T18uninitializedArrayTAhTymZ.uninitializedArray() ()

#10 0x00806724 in std.file.readImpl() ()
#11 0x00780b49 in std.file.__T4readTAyaZ.read() ()
#12 0x0073357c in mkk_site.utils.getPageTemplate() ()
#13 0x00733243 in mkk_site.utils.getGeneralTemplate() ()
#14 0x0072ed8f in 
mkk_site.uri_page_router.MKK_Site_URIPageRouter.renderMessageBody() ()
#15 0x0072ecba in 
mkk_site.uri_page_router.MKK_Site_URIPageRouter.customProcessRequest() ()
#16 0x0079fa03 in 
webtank.net.http.handler.EventBasedHTTPHandler.processRequest() ()
#17 0x0079fc43 in 
webtank.net.http.handler.HTTPRouter.customProcessRequest() ()
#18 0x0079fa03 in 
webtank.net.http.handler.EventBasedHTTPHandler.processRequest() ()
#19 0x00755692 in 
webtank.net.web_server.WorkingThread._work() ()

#20 0x008257de in core.thread.Thread.run() ()
#21 0x00825422 in thread_entryPoint ()
#22 0x775ba182 in start_thread (arg=0x71cb1700) at 
pthread_create.c:312
#23 0x770df47d in clone () at 
../sysdeps/unix/sysv/linux/x86_64/clone.S:111


Thread 3 (Thread 0x724b2700 (LWP 30860)):
#0  __lll_lock_wait () at 
../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
#1  0x775bc672 in _L_lock_953 () from 
/lib/x86_64-linux-gnu/libpthread.so.0
#2  0x775bc4da in __GI___pthread_mutex_lock 
(mutex=0xac58a0 )

at ../nptl/pthread_mutex_lock.c:114
#3  0x007f33b1 in core.sync.mutex.Mutex.lock_nothrow() ()
#4  0x00827445 in gc.gc.GCMutex.lock() ()
#5  0x00827c52 in gc.gc.GC.malloc() ()
#6  0x007f36cc in gc_malloc ()
#7  0x007f09f0 in core.memory.GC.malloc() ()
#8  0x0075985c in 
std.array.__T14arrayAllocImplVbi0TAaTmZ.arrayAllocImpl() ()
#9  0x00759839 in 
std.array.__T18uninitializedArrayTAaTmZ.uninitializedArray() ()
#10 0x0075981d in 
std.array.__T5arrayTS3std4conv47__T7toCharsVii10TaVE3std5ascii10LetterCasei1TmZ7toCharsFNaNbNiNfmZ6ResultZ.array() ()
#11 0x0075978b in 
std.array.__T5arrayTS3std4conv47__T7toCharsVii10TaVE3std5ascii10LetterCasei1TmZ7toCharsFNaNbNiNfmZ6ResultZ.array() ()

#12 0x00719122 in std.conv.__T6toImplTAyaTmZ.toImpl() ()
#13 0x007190b3 in std.conv.__T6toImplTAyaTmZ.toImpl() ()
#14 0x00719099 in std.conv.__T2toTAyaZ.__T2toTmZ.to() ()
#15 0x007d1f04 in 
webtank.common.logger.FileLogger.writeEvent() ()
#16 0x007d2183 in 
webtank.common.logger.ThreadedLogger._run() ()
#17 0x007d4141 in 
std.concurrency.Message.__T3mapTDFS7webtank6common6logger8LogEventZvZ.map() ()
#18 0x007d3a79 in 
std.concurrency.MessageBox.__T3getTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.get() ()
#19 0x007d3e79 in 
std.concurrency.MessageBox.__T3getTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.get() ()
#20 0x007d39a6 in 
std.concurrency.MessageBox.__T3getTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.get() ()
#21 0x007d380b in 
std.concurrency.__T7receiveTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.receive() ()
#22 0x007d215b in 
webtank.common.logger.ThreadedLogger._run() ()
#23 0x007d237d in 
std.concurrency.__T6_spawnTPFS3std11concurrency3TidOC7webtank6common6logger6LoggerZvTS3std11concurrency3TidTOC7webtank6common6logger6LoggerZ._spawn() ()

---Type  to continue, or q  to quit---
#24 0x008257de in core.thread.Thread.run() ()
#25 0x00825422 in thread_entryPoint ()
#26 0x775ba182 in start_thread 

Re: Need some help about error that I don't understand

[Uranuz via Digitalmars-d-learn]

On Friday, 5 February 2016 at 17:39:55 UTC, Uranuz wrote:
In my custom multithreaded web-server (non vibe-based) I got 
error that is strange for me. I've was looking for a reason 
running app under GDB, but I don't understand how to interpret 
what I've got.


It's interesting that it fails (without any error or segfault 
message) in the case when null reference to class object passed 
into static method of class. When it's not null all goes well. 
So there is backtrace:


//---
(gdb) thread apply all bt

Thread 4 (Thread 0x71cb1700 (LWP 30869)):
#0  sem_wait () at 
../nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S:85

#1  0x0084747f in core.thread.suspend() ()
#2  0x00839467 in thread_suspendAll ()
#3  0x0082bd88 in gc.gc.Gcx.fullcollect() ()
#4  0x0082a43d in gc.gc.Gcx.bigAlloc() ()
#5  0x00827ca5 in gc.gc.GC.malloc() ()
#6  0x007f36cc in gc_malloc ()
#7  0x007f09f0 in core.memory.GC.malloc() ()
#8  0x008321cf in 
std.array.__T14arrayAllocImplVbi0TAhTmZ.arrayAllocImpl() ()
#9  0x008321a1 in 
std.array.__T18uninitializedArrayTAhTymZ.uninitializedArray() ()

#10 0x00806724 in std.file.readImpl() ()
#11 0x00780b49 in std.file.__T4readTAyaZ.read() ()
#12 0x0073357c in mkk_site.utils.getPageTemplate() ()
#13 0x00733243 in mkk_site.utils.getGeneralTemplate() ()
#14 0x0072ed8f in 
mkk_site.uri_page_router.MKK_Site_URIPageRouter.renderMessageBody() ()
#15 0x0072ecba in 
mkk_site.uri_page_router.MKK_Site_URIPageRouter.customProcessRequest() ()
#16 0x0079fa03 in 
webtank.net.http.handler.EventBasedHTTPHandler.processRequest() 
()
#17 0x0079fc43 in 
webtank.net.http.handler.HTTPRouter.customProcessRequest() ()
#18 0x0079fa03 in 
webtank.net.http.handler.EventBasedHTTPHandler.processRequest() 
()
#19 0x00755692 in 
webtank.net.web_server.WorkingThread._work() ()

#20 0x008257de in core.thread.Thread.run() ()
#21 0x00825422 in thread_entryPoint ()
#22 0x775ba182 in start_thread (arg=0x71cb1700) at 
pthread_create.c:312
#23 0x770df47d in clone () at 
../sysdeps/unix/sysv/linux/x86_64/clone.S:111


Thread 3 (Thread 0x724b2700 (LWP 30860)):
#0  __lll_lock_wait () at 
../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135
#1  0x775bc672 in _L_lock_953 () from 
/lib/x86_64-linux-gnu/libpthread.so.0
#2  0x775bc4da in __GI___pthread_mutex_lock 
(mutex=0xac58a0 )

at ../nptl/pthread_mutex_lock.c:114
#3  0x007f33b1 in core.sync.mutex.Mutex.lock_nothrow() 
()

#4  0x00827445 in gc.gc.GCMutex.lock() ()
#5  0x00827c52 in gc.gc.GC.malloc() ()
#6  0x007f36cc in gc_malloc ()
#7  0x007f09f0 in core.memory.GC.malloc() ()
#8  0x0075985c in 
std.array.__T14arrayAllocImplVbi0TAaTmZ.arrayAllocImpl() ()
#9  0x00759839 in 
std.array.__T18uninitializedArrayTAaTmZ.uninitializedArray() ()
#10 0x0075981d in 
std.array.__T5arrayTS3std4conv47__T7toCharsVii10TaVE3std5ascii10LetterCasei1TmZ7toCharsFNaNbNiNfmZ6ResultZ.array() ()
#11 0x0075978b in 
std.array.__T5arrayTS3std4conv47__T7toCharsVii10TaVE3std5ascii10LetterCasei1TmZ7toCharsFNaNbNiNfmZ6ResultZ.array() ()

#12 0x00719122 in std.conv.__T6toImplTAyaTmZ.toImpl() ()
#13 0x007190b3 in std.conv.__T6toImplTAyaTmZ.toImpl() ()
#14 0x00719099 in std.conv.__T2toTAyaZ.__T2toTmZ.to() ()
#15 0x007d1f04 in 
webtank.common.logger.FileLogger.writeEvent() ()
#16 0x007d2183 in 
webtank.common.logger.ThreadedLogger._run() ()
#17 0x007d4141 in 
std.concurrency.Message.__T3mapTDFS7webtank6common6logger8LogEventZvZ.map() ()
#18 0x007d3a79 in 
std.concurrency.MessageBox.__T3getTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.get() ()
#19 0x007d3e79 in 
std.concurrency.MessageBox.__T3getTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.get() ()
#20 0x007d39a6 in 
std.concurrency.MessageBox.__T3getTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.get() ()
#21 0x007d380b in 
std.concurrency.__T7receiveTDFS7webtank6common6logger8LogEventZvTDFNaNbNiNfS7webtank6common6logger14ThreadedLogger10LogStopMsgZvTDFC3std11concurrency15OwnerTerminatedZvZ.receive() ()
#22 0x007d215b in 
webtank.common.logger.ThreadedLogger._run() ()
#23 0x007d237d in 
std.concurrency.__T6_spawnTPFS3std11concurrency3TidOC7webtank6common6logger6LoggerZvTS3std11concurrency3TidTOC7webtank6common6logger6LoggerZ._spawn() ()

---Type  to continue, or q  to quit---
#24 0x008257de in core.thread.Thread.run() ()
#25 0x00825422 in 

Question about OutputRange and std.range: put

[Uranuz via Digitalmars-d-learn]

Hello to forum readers!
I have a question about using OutputRange and std.range: put. I 
have the following code snippet to illustrate my question:


import std.range, std.stdio, std.string;

void main()
{
string greating = "Hello, "   ;
string username = "Bob";

put(greating, username);
put(greating, "!");

writeln(greating);
}

It doesn't compile. It says following:

Compilation output:
/opt/compilers/dmd2/include/std/range/primitives.d(335): Error: 
static assert  "Cannot put a string into a string."
/d52/f530.d(8):instantiated from here: put!(string, 
string)


Documentation about std.range.put says that one of code snippets, 
where *put* applies is when second argument is array of elements 
(If I understand it correctly with my knowledge of English). 
Especially the following line is there in doc for usage scenario:


r.doPut([ e ]); R specifically accepts an E[].

Can I put range or array f elements as second argument of put or 
it works only at per element basis? I think writing multiple 
items at a time should be more effective but maybe it's not 
supported for OutputRange? Could someone explain?

Re: Question about OutputRange and std.range: put

[Uranuz via Digitalmars-d-learn]

On Saturday, 16 January 2016 at 16:14:56 UTC, Jonathan M Davis 
wrote:
On Saturday, January 16, 2016 12:11:11 Uranuz via 
Digitalmars-d-learn wrote:

[...]


There are a few problems here. First off, when put is used with 
an array, it fills the array. It doesn't append to it. So, you 
can't use a string as an output range, since its elements are 
immutable. Here's an example with int[]:


[...]


Thanks for your response. After looking for some time in Phobos 
documentation I already found that it would be better to use 
Appender for this purpose. As far as I understand it allocates 
less often and I can reserve some memory from the start. I'll 
take this possibility into account when I'll do further small 
optimisations. Thanks again.

Re: Problem with using struct ranges with @disabled this(this) with some range functions

[Uranuz via Digitalmars-d-learn]

On Wednesday, 2 September 2015 at 07:34:15 UTC, Mike Parker wrote:

On Wednesday, 2 September 2015 at 06:28:52 UTC, Uranuz wrote:
As far as I understand to save current cursor of forward range 
I should always use *save* property. But sometimes range 
struct is just copied using postblit without using save (it 
happens even in Phobos). Is it correct behaviour to *pass 
ownership* for range structs via just copying of range or not. 
As I think for at least *forward* ranges that are structs we 
must always use save methot to store new cursor. But for 
*input* ranges it is not possible, so there maybe plain 
copying could be allowed. I thing that we should work out some 
descision on this problem, provide some unittests for 
different types of ranges with and without postblit for 
standard Phobos functions and fix them accordingly.


I have problem with std.range.take function and forward range 
with disabled postblit and I don't understand is it my or 
library bug?


My understanding is that one underlying assumption in Phobos 
about ranges is that they are lightweight and single-minded -- 
they should carry no state other than what is necessary to 
fulfill the range interface they provide. This follows from the 
idea that, given a container, you do not slap a range interface 
on the container type and pass container instances to 
range-based functions, but instead implement a range type 
separate from the container that knows where the elements of 
the container begin and end and nothing else. They do not carry 
the elements of the container around with them.


Looking at ranges from that angle, the need to disable postblit 
on a range type would be a special case. That raises the 
question, for what reason have you disabled postblit on your 
range type? Is it not possible for you to create a lightweight 
range from your data?


I want to understand if we have *save* method in Forward Range 
then why or in which cases we should use plain struct copying 
instead. Should we assume that these two ways are equal or not?


Also as far as I understand behaviour for Input Ranges vs Forward 
Ranges would be different, because you could not store cursor on 
object like network data stream, because as soon as you read from 
it you cannot save some range that will point on previous bytes 
in network stream, because they are gone if you read them.


So for Input Range copy will always point on current state, but 
not previois state, that was saved before in another range 
pointing to the same source.


For Forward Range we have ability to save cursor position and 
return to it later. In this case would copying via postblit would 
be equal to *save* method or would be similar as for Input Range.

Problem with using struct ranges with @disabled this(this) with some range functions

[Uranuz via Digitalmars-d-learn]

As far as I understand to save current cursor of forward range I 
should always use *save* property. But sometimes range struct is 
just copied using postblit without using save (it happens even in 
Phobos). Is it correct behaviour to *pass ownership* for range 
structs via just copying of range or not. As I think for at least 
*forward* ranges that are structs we must always use save methot 
to store new cursor. But for *input* ranges it is not possible, 
so there maybe plain copying could be allowed. I thing that we 
should work out some descision on this problem, provide some 
unittests for different types of ranges with and without postblit 
for standard Phobos functions and fix them accordingly.


I have problem with std.range.take function and forward range 
with disabled postblit and I don't understand is it my or library 
bug?

Re: Passing reference data to class and incapsulation

[Uranuz via Digitalmars-d-learn]

On Friday, 28 November 2014 at 08:31:26 UTC, bearophile wrote:

Uranuz:

Same situation happens when I assign reference data to 
properties.


Someone has suggested to solve this problem with an attribute, 
like owned, that forbids to return mutable reference data 
owned by a class/struct instance.


Bye,
bearophuile


Yes. Problem is even if you have property that controls correct 
assignment. If you have getter that returns mutable reference 
type and you try to access some fields of it or apply index 
operator (for arrays or AA) *host* cannot control corectness of 
these assignments or cannot react to these changes (in order to 
do some changes in model).


The way I see is to create my own type of Array for this that can 
notify *host object* about changes so it could refresh the model 
or do some checks.


Another way is to write interfaces in a way so we cant't escape 
uncontrolled references to mutable data.


What do you think of it? Is there any patterns that could help to 
solve such problems?


I think that writing your own type every time when you need to 
enforce consistency and safety is not very good))

Passing reference data to class and incapsulation

[Uranuz via Digitalmars-d-learn]

In D we a several data types which are passed by reference: 
dynamic arrays, associative arrays. And sometimes we need to pass 
these reference data to class instance to store it inside. One of 
the principles of object-oriented programming is incapsulation. 
So all class data should be only modyfiable via class methods and 
properties. But I we pass reference data to class (for example as 
parameter in constructor) we still can change these data from 
initial code and break some internal logic of class for modifying 
these data. Example:


class Foo {
this(int[] b) { bar = b; }
private int[] bar;
//Some methods
}

void main() {
int[] bar = [1,2,3,4,5];
Foo foo = new Foo(bar);
//There I could do some logic with class
bar[2] = 6; //I modify class without some checks from class
//And there I might pass *bar* somewhere outside and break 
incapsulation

}

Same situation happens when I assign reference data to 
properties. I can check or do something with data at the moment 
of assignment, but I can't control that someone will modify using 
initial reference from outside. So do you copy reference data in 
constructors or properties? Should it be? Or call site should be 
responsible for not escaping reference somewhere outside and not 
modifying these data badly?


There also possible some situations when these data should be 
shared between different pieces of code (for example different 
class instance could reference the same memory area). But I think 
this is not very good and safe approach and should be avoided if 
possible.


But I think storing reference to class inside another class could 
be good approach because there could be different type of 
relations between classes. For plain data types we often have 
types of relations: *ownership* or *aggregation*. But classes can 
usualy have more types of relations: *usage* or when one class 
subscribes for events of another.


Is there some good links to read for these questions that you 
could advice. After several hours of googling I haven't found 
good topics about these problems. And I have not enough time for 
reading big book.

Question about eponymous template trick

[Uranuz via Digitalmars-d-learn]

I have an example of code like this:

template Node(String)
{
struct Node {}
struct Name {}
struct Attr {}

}

void main()
{
alias MyNode = Node!(string).Node;
alias MyName = Node!(string).Name;
alias MyAttr = Node!(string).Attr;

}

This code fails during compilation with message:

Compilation output:

/d228/f410.d(12): Error: no property 'Node' for type 
'Node!string' /d228/f410.d(12): Error: no property 'Node' for 
type 'Node!string' /d228/f410.d(13): Error: no property 'Name' 
for type 'Node!string' /d228/f410.d(13): Error: no property 
'Name' for type 'Node!string' /d228/f410.d(14): Error: no 
property 'Attr' for type 'Node!string' /d228/f410.d(14): Error: 
no property 'Attr' for type 'Node!string'


So question is: is this intended behaviour and I'm missing 
something about eponymous templates? Or is it a bug in compiler?

Re: Question about eponymous template trick

[Uranuz via Digitalmars-d-learn]

Looks like compiler looks for Node, Name and Attr in Node 
struct, because of eponymous thing.


I understand it but I want to know if it is documented behaviour 
or not. Could anybody clear what happens with eponymous stuff and 
why I can't get acces to *other* declarations inside eponymous 
template? I guess that it is not intended behaviour.

Re: Question about eponymous template trick

[Uranuz via Digitalmars-d-learn]

I think it's the intended behavior. I think documentation is 
outdated.


Ali


Thanks. So I will modify my programme to workaround this.

Re: Question about eponymous template trick

[Uranuz via Digitalmars-d-learn]

Also I failed to find any documentation about eponymous stuff in 
language reference. As far as I remember it was here but now 
looks like it is missing.

Representing parse tree node

[Uranuz via Digitalmars-d-learn]

Now I'm working on implementation of Jinja template engine for 
web development on D language.


http://jinja.pocoo.org

I like it's explicit but still rather short syntax inherited from 
Python. I find it good for writing templates for web pages and 
other stuff such as configs or maybe CSS files.


But I have a problem in my head about better way of representing 
parse tree node in D. So I want to ask an advice from people who 
have some experience in working with grammars, parsing, creating 
compilers, etc. Currently my lexer algorithm is implemented with 
small amount of allocations using plain structs everywhere.


So one of my considerations is that it would be good to implement 
parser with as less allocations as possible or at least 
consolidate it in one place. In this case it could be possible to 
switch allocation policy easily.


Now about parse tree nodes. Tree node has set of field of *Node* 
type, and also can be list of Nodes (Node[]) or can contain plain 
values (string. bool. int). One way is to implement node as 
struct like std.json does it.


enum NodeType { /+...+/}

struct Node
{
   NodeType type;

   Node[string] fileds;
   Node[] list;

   //Could store plain values
   int integer;
   bool boolean;
   string str;
   float floating;

   Lexeme lex; //Stores info about corresponding lexeme
}

Some of these fields can be merged into *union* to make it more 
memory efficient. So there is two data types that will reallocate 
when I'll be operating on them: array and associative array.


Another way is using of base class/interface for Node and have 
separate class for each node type. For example


class Node {
   //...
}

class Statement: Node {
   //...
}

class Expr: Node {
   //...
}

class If : Statement {
   Expr test;
   Node body_;
   Node else_;
}

class Literal: Node {

}

class List: Literal {
   Node[] list;
}

class Integer: Literal {
   int value;
}

So as I see there I'll have more allocation taking class 
allocations into account. And what is the benefit of it if I 
using parse tree node as just data storing structure without 
methods?


What is a standard apprach implementing parse tree node?

Re: How to check i

[Uranuz via Digitalmars-d-learn]

This is

Re: How to match string by word

[Uranuz via Digitalmars-d-learn]

I haven't touched any key on a keyboard and haven't pressed 
*Send* but message was posted somehow.


Thanks. Checking for UTF-8 continuation bytes is good idea. Also 
I agree that UTF-16 is more difficult. I will keep it for future 
release when implementation will start to work properly on UTF-8 
and UTF-32

How to check i

[Uranuz via Digitalmars-d-learn]

I have some string *str* of unicode characters. The question is 
how to check if I have valid unicode code point starting at code 
unit *index*?


I need it because I try to write parser that operates on string 
by *code unit*. If more precisely I trying to write function 
*matchWord* that should exctract whole words (that could consist 
not only English letters) from text. This word then compared with 
word from parameter. I want to not decode if it is not necessary. 
But looks like I can't do it without decoding, because I need to 
know if current character is letter of alphabet and not 
punctuation or whitespace for example.


There is how I think this look like. In real code I have template 
algorithm that operates on differrent types of strings: string, 
wstring, dstring.


struct Lexer
{
string str;
size_t index;

bool matchWord(string word)
{
size_t i = index;
while( !str[i..$].empty )
{
if( !str.isValidChar(i) )
{
i++;
continue;
}

uint len = str.graphemeStride(i);

if( !isAlpha(str[i..i+len]) )
{
break;
}
i++;
}

return word == str[index..i];
}
}

It is just a draft of idea. Maybe it is complicated. What I want 
to get as a result is logical flag (matched or not) and position 
should be set after word if it is matched. And it should match 
whole words of course.


How do I implement it correctly without overhead and additional 
UTF decodings if possible?


And also how could I validate single char of string starting at 
code unit index? Also I don't like that graphemeStride can throw 
Exception if I point to wrong possition. Is there some nothrow 
version? I don't want to have extra allocations for exceptions.

Re: How to detect start of Unicode symbol and count amount of graphemes

[Uranuz via Digitalmars-d-learn]

Have a look here [1]. For example, if you have a byte that is 
between U+0080 and U+07FF you know that you need two bytes to 
get that whole code point.


[1] http://en.wikipedia.org/wiki/UTF-8#Description


Thanks. I solved it myself already for UTF-8 encoding. There 
choosed approach with using bitbask. Maybe it is not best with 
eficiency but it works)


( str[index]  0b1000 ) == 0 ||
( str[index]  0b1110 ) == 0b1100 ||
( str[index]  0b ) == 0b1110 ||
( str[index]  0b1000 ) == 0b

If it is true it means that first byte of sequence found and I 
can count them. Am I right that it equals to number of graphemes, 
or are there some exceptions from this rule?


For UTF-32 number of codeUnits is just equal to number of 
graphemes. And what about UTF-16? Is it possible to detect first 
codeUnit of encoding sequence?

How to detect start of Unicode symbol and count amount of graphemes

[Uranuz via Digitalmars-d-learn]

I have struct StringStream that I use to go through and parse 
input string. String could be of string, wstring or dstring type. 
I implement function popChar that reads codeUnit from Stream. I 
want to have *debug* mode of parser (via CT switch), where I 
could get information about lineIndex, codeUnitIndex, 
graphemeIndex. So I don't want to use *front* primitive because 
it autodecodes everywhere, but I want to get info abot index of 
*user perceived character* in debug mode (so decoding is needed 
here).


Question is how to detect that I go from one Unicode grapheme to 
another when iterating on string, wstring, dstring by code unit? 
Is it simple or is it attempt to reimplement a big piece of 
existing std library code?


As a result I should just increment internal graphemeIndex.

There short version of implementation that I want follows

struct StringStream(String)
{
   String str;
   size_t index;
   size_t graphemeIndex;

   auto popChar()
   {
  index++;
  if( ??? ) //How to detect new grapheme?
  {
 graphemeIndex++;
  }
  return str[index];
   }

}

Sorry for very simple question. I just have a mess in my head 
about Unicode and D strings

Re: How to detect start of Unicode symbol and count amount of graphemes

[Uranuz via Digitalmars-d-learn]

You can use std.uni.byGrapheme to iterate by graphemes:
http://dlang.org/phobos/std_uni.html#.byGrapheme

AFAIK, graphemes are not self synchronizing, but codepoints 
are. You can pop code units until you reach the beginning of a 
new codepoint. From there, you can iterate by graphemes, though 
your first grapheme might be off.


Maybe there is some idea how to just detect first code unit of 
grapheme without overhead for using Grapheme struct? I just tried 
to check if ch  128 (for UTF-8). But this dont work. How to 
check if byte is continuation of code for single code point or if 
new sequence started?

Re: sdlang-d can not link after updating to dmd 2.066

[Uranuz via Digitalmars-d-learn]

On Thursday, 28 August 2014 at 10:16:15 UTC, Puming wrote:

I updated dub to 0.9.22 and still got the same error...

THis is the output of `dub build --force`:

--- output ---

## Warning for package sdlang-d ##

The following compiler flags have been specified in the package 
description
file. They are handled by DUB and direct use in packages is 
discouraged.
Alternatively, you can set the DFLAGS environment variable to 
pass custom flags

to the compiler, or use one of the suggestions below:

-wi: Use the buildRequirements field to control warning 
behavior



## Warning for package sdlang-d, configuration unittest ##

The following compiler flags have been specified in the package 
description
file. They are handled by DUB and direct use in packages is 
discouraged.
Alternatively, you can set the DFLAGS environment variable to 
pass custom flags

to the compiler, or use one of the suggestions below:

-debug: Call dub with --build=debug
-unittest: Call dub with --build=unittest


## Warning for package sdlang-d ##

The following compiler flags have been specified in the package 
description
file. They are handled by DUB and direct use in packages is 
discouraged.
Alternatively, you can set the DFLAGS environment variable to 
pass custom flags

to the compiler, or use one of the suggestions below:

-wi: Use the buildRequirements field to control warning 
behavior



## Warning for package sdlang-d, configuration unittest ##

The following compiler flags have been specified in the package 
description
file. They are handled by DUB and direct use in packages is 
discouraged.
Alternatively, you can set the DFLAGS environment variable to 
pass custom flags

to the compiler, or use one of the suggestions below:

-debug: Call dub with --build=debug
-unittest: Call dub with --build=unittest

Building sdlang-d 0.8.4 configuration library, build type 
debug.

Running dmd...
Building haha ~master configuration application, build type 
debug.

Compiling using dmd...
Linking...
Undefined symbols for architecture x86_64:
  
_D7sdlang_3ast3Tag103__T11MemberRangeTC7sdlang_3ast3TagVAyaa7_616c6c54616773VAyaa11_746167496e646963696573VAyaa5_5f74616773Z11MemberRange11__invariantMxFZv, 
referenced from:
  
_D7sdlang_3ast3Tag103__T11MemberRangeTC7sdlang_3ast3TagVAyaa7_616c6c54616773VAyaa11_746167496e646963696573VAyaa5_5f74616773Z11MemberRange30__T13opBinaryRightVAyaa2_696eZ13opBinaryRightMFAyaZb 
in haha.o

ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to 
see invocation)

--- errorlevel 1
FAIL 
.dub/build/application-debug-posix.osx-x86_64-dmd-561BEB9B9938BB39E9AD2177AB127CD0/ 
haha executable

Error executing command build: dmd failed with exit code 1.

-- end ---


On Wednesday, 27 August 2014 at 16:35:18 UTC, Israel wrote:


It looks fine here, OSX 10.9.4

sdlang-d: =0.8.4

Im using DUB RC2 though


I get strange link errors when using scoped imports sometimes. 
It's often in the case when scoped import placed at the same 
nesting level as ising some symbol from imported module. I don't 
know exactly what happens here, but most of cases that I faced is 
about it. Other possibility is connected with calling abstract 
methods in classes.

Re: Question about operations on class/struct properties

[Uranuz via Digitalmars-d-learn]

I have another similar example illustrating this problem at 
semantic level.


import std.stdio, std.typecons;

struct Test
{
//ref
Nullable!int prop() @property
{
return _value;
}

private Nullable!int _value = 10;

}


void main()
{

auto test = Test();

//This looks like I want to modify property with *nullify*,
	//but instead it creates variable that will never be used and 
modify it

test.prop.nullify();

assert( test.prop.isNull ); //This fails
}

So when using with value types I should always look if property 
is *ref* or not and it's not very good.


I have another question. How could I implement in this example if 
I uncomment it to call some function after modifying property? Do 
I need some sort of class wrapper for property or is there some 
other ideas?



What I expect:

void main()
{
auto test = Test();

test.prop.nullify();
//Callback called after this operation

test.prop = 15;
//Callback called after this operation too
}

Callback is simple method of Test like:

void callback(Nullable!int value)
{
if( value.isNull )
//Do smth
else if( value = 0 )
//Do smth else
else //Just assign to internal field
_value = value;
}


So I think it is possible to do this with some class wrapper 
around Nullable!int that should implement al of it's methods or 
for example dispatching calls to them via opDispacth. But this 
approach looks slightly complicated. What if I have complicated 
interface (for example std.datetime.Date as such property) so I 
need to reimplement or dispatch a lot of methods.


Could you advise another more simple approach to this problem?

Question about operations on class/struct properties

[Uranuz via Digitalmars-d-learn]

I think there is something that I don't understand about concept 
of *properties*. I thing that property is sort of object 
attribute that belongs to it. Currently property considered as 
two functions: *get* and/or *set*. So we can do two sort of 
operations on concept that called *property*: *assign to it* and 
*read it*. If property doesn't return reference value all other 
manipulations are forbidden. A will illustrate it with example:


import std.datetime, std.stdio;

void main()
{
auto date = Date(1991, 5, 7);
//date.day += 5; //Not working
//date.day++;  //Not working
date.day = date.day + 1;
}

Because day property is of ubyte (not reference) type, we can 
only read it into some other variable or assign to it, but other 
other operations couldn't be done.


It is a common case when I want to increment, decrement or using 
some other 'op=' - operation, but it is not working and I get 
compile-time error. I always was thinking that


date.day++;
date.day -= 5;

Should be treated as:

date.day = date.day + 1;
date.day = date.day - 5;

if the were not oveloaded. So if we have get and set property 
methods I see that it could be calculated and this should working.


Of course I can define return value of get property as *ref* but 
in this case I don't understand how I should use it with *setter* 
method.


It's interesting to see any thinkings about it.

Re: Question about operations on class/struct properties

[Uranuz via Digitalmars-d-learn]

On Monday, 18 August 2014 at 18:07:09 UTC, Phil Lavoie wrote:
All you said makes sense. If there is a direct connection 
between getter, setter and member than yes, returning it by 
reference is usually more convenient:


private T _member;
@property ref inout(T) member() inout {return _member;}

However, sometimes, there is no direct connection between field 
and mutators. Sometimes, it is calculated on the fly.


Yes. As you said often it calculated on the fly. And sometimes 
when setting some value you need to trigger some *event handler*. 
This is one of use cases that properties were designed in 
different languages. Another case is to check value and throw 
exception or something else. So using getter that returns 
reference is very close to just exposing class/ struct field and 
allowing to modify it directly. I think that *setter* should 
shadow *ref getter* in opAssign and opOpAssign expressions. And 
opOpAssign should rewrite into *read - execute operation - 
write* sequence.


Also I have another interesting question. For example I have some 
struct (value object) that has method, that modifies it's state. 
Then I declare some class/ struct that has property of value type.


Problem is that logically I could expect that this method should 
modify property of class, but instead some value return from 
property method returned (by value) and then it is was modified.


I'll give short illustration.


struct PropType
{

}

Re: Question about operations on class/struct properties

[Uranuz via Digitalmars-d-learn]

I posted it suddenly. I don't know why.


I'll give short illustration.


struct PropType
{
   void append(int value)
   {
  //implementation
   }

}

class Test
{
   PropType myProp() @property
   {
  return _propValue;
   }

   private PropType _propValue;

}

void main()
{
   Test test = new Test;

   //This line looks like I want to append value
   //to field of *test* object. But it cant't modify
   //it and just doing useless job.
   test.myProp.append(10);

}


I don't know intentions of language designers in part of 
properties. But in this code I see some logical contradiction. 
What I see and thinking of this line of code it is not what it 
really does.


I don't know much about properties behaviour in different 
languages but there is something that confuses me. I believe that 
this problem deserves more attention. There are 5 DIP's in dlang 
wiki. So I think it's important

Re: Help with porting grammar from PEGjs to D for dustjs project!

[Uranuz via Digitalmars-d-learn]

What I was thinking about is possibility to change ParseTree 
struct with user-defined version of it. And I was thinking about 
setting tree type as template parameter to grammar:


grammar!(MyParseTree)(
Arithmetic:
   ...
);

Or somethink like this. I think changing source code of library 
in order to change tree type is not good and should be set as 
parameter. If it's already implemented please let me knoe because 
I couldn't find it. And also some minimal interface is needed to 
be described in documentation for ParseTree (may be ability to 
set it as class is good in order to have polymorthic nodes with 
different methods and properties).


Of course I can transform PEGGED syntactic tree into another form 
of tree specified by usage domain. But if it doesn't 
significantly differs from PEGGED tree (for example node have a 
pair of additional properties) it only causes into additional 
memory consumption and CPU to transform tree. But if domain 
specific tree differs a lot of course we need some useful way to 
transform trees.

Re: Help with porting grammar from PEGjs to D for dustjs project!

[Uranuz via Digitalmars-d-learn]

Different formats and also different languages. I don't see how 
you
can compare a parse tree that's a D object and another tree 
made by

dustjs: you never see the AST produced by dust, you only see the
resulting JS code.


Yes. That's a point. Thanks for all the explanations. I'll try to 
make something useful of it.

Re: Help with porting grammar from PEGjs to D for dustjs project!

[Uranuz via Digitalmars-d-learn]

On Tuesday, 5 August 2014 at 08:13:25 UTC, Uranuz wrote:
Different formats and also different languages. I don't see 
how you
can compare a parse tree that's a D object and another tree 
made by
dustjs: you never see the AST produced by dust, you only see 
the

resulting JS code.


Yes. That's a point. Thanks for all the explanations. I'll try 
to make something useful of it.


Is there multiline comments available inside PEGGED template?
As far as I understand inline comments are set via # sign.

Help with porting grammar from PEGjs to D for dustjs project!

[Uranuz via Digitalmars-d-learn]

I want to try to implement web template engine dustjs:
http://akdubya.github.io/dustjs/

At the first step implementing parser for it's grammar is needed. 
As far as code for parsing grammar was generated via PEGjs 
grammar generator the resulting code is enough long (about 4200 
lines of code). I though that it is productive way to make 
porting manually. It's long and something could change in the 
source JavaScript code. And it will be not so easy to maintain. 
So I remembered about PEGGED project for D. As I see formats for 
writing grammar differs for these two systems and I have no 
experience with using grammar generators.


So I need some help with rewriting grammar from PEGjs into PEGGED.

Also I don't understand in PEGGED (I have not tried to use it 
yet) how to generate some logic from AST. Where should I describe 
it or should I walk around all nodes for somehow and generate 
code for them.


Goal of this is to use dust template system as template engine at 
server side. I also considered handlebars.js, but I can't 
evaluate what is more suitable for my purposes. The choice is 
just very subjective.

Re: Help with porting grammar from PEGjs to D for dustjs project!

[Uranuz via Digitalmars-d-learn]

I am real noob about grammar description languages so I need some 
explanation about it. As far as I understand expressions in curly 
bracers are used to modify syntax tree just in process of parsing 
instead of modifying it after?


How I could use PEGGED to map some code to these parsed 
expressions to generate code that will perform operations defined 
by this grammar? Should I walk around all the syntax tree and 
just append code to some string and mix it in then or are there 
some features for code generation?


Something that I was thinking about is comparision of resulting 
syntax tree to check if it was correctly implemented. It would be 
great if different gramar parsers will output result in common 
format (JSON or XML for example) and it will be possiple to 
compare them for equality. But different parsers have different 
internal format of tree so maybe creating some transformation is 
possible. With this feature it could be possible to say if parser 
is working correctly.

Re: How to say to compiler that I want to inherit final template bethod of base interface into derived class

[Uranuz via Digitalmars-d-learn]

On Sunday, 20 July 2014 at 12:48:09 UTC, anonymous wrote:

import std.stdio;

interface IBase
{

template getStr(string fieldName)
{
final string getStr()
{
return George;
}
}


string getStr(string fieldName);
}


class Derived: IBase
{
alias getStr = IBase.getStr; /* order matters, see below */
override string getStr(string fieldName)
{
return Sam;
}
/* alias getStr = IBase.getStr; /* doesn't work here, I guess
that's a compiler bug */
}


void main()
{
auto obj = new Derived;

assert( obj.getStr!(aaa)() == George );
assert( obj.getStr(aaa) == Sam );

}


Sorry, but this example doesn't work too.

Re: How to say to compiler that I want to inherit final template bethod of base interface into derived class

[Uranuz via Digitalmars-d-learn]

On Sunday, 20 July 2014 at 16:12:20 UTC, anonymous wrote:

On Sunday, 20 July 2014 at 15:48:19 UTC, Uranuz wrote:

Sorry, but this example doesn't work too.


Ugh, 2.065 doesn't like it, but it works for me with git head
(v2.066-devel-82b031c).


Where did you get it? Or you compiled it yourself? Because I 
tried beta4 and it doesn't work there too.

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

On Monday, 23 June 2014 at 18:32:38 UTC, Steven Schveighoffer 
wrote:
On Sun, 22 Jun 2014 08:23:45 -0400, Uranuz neura...@gmail.com 
wrote:


If these rules are not so clear and have some exceptions (but 
I don't understand why they are needed) then some 
documentation needed about this.


See integer promotion rules:

http://dlang.org/type.html#Integer%20Promotions

And the section below it.

-Steve


I see these rules but when I compile following code and it fails 
with error it looks VERY stupid.


import std.stdio;

void main()
{
ubyte a = 15;
ubyte b = 10;

	ubyte c = a + b; //What is happening there?! ARGH! Are you 
joking?!


}

Compilation output:
/d837/f382.d(9): Error: cannot implicitly convert expression 
(cast(int)a + cast(int)b) of type int to ubyte


I'm just crazy about it! How could it happen?!

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

In C/C++/D if you sum a types that are smaller than int, you 
obtain an int. D has copied C for backwards compatibility with 
C code.


Bye,
bearophile


Is there any reasoning why this should remain unchainged? How 
could it break interface between languages? And also this code 
succesfully compiles and runs in C++.


#include iostream

using namespace std;

int main()
{
   unsigned short a = 15;
   unsigned short b = 10;

   unsigned short c = a + b;  //There is no problem

   cout  c  endl;

   return 0;
}

As D compiler doesn't need to compile C programme and have 
compatible operations with types. Why we still should keep this 
garbage?!


I don't know the right solution but I believe that previous 
example illustrates some contradiction in integer types system 
design or implementation.


Why we dont promote *ulong* and *long* to int? Let's also promote 
string into array of ints?! Can't believe it!

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

I see these rules but when I compile following code and it 
fails with error it looks VERY stupid.


import std.stdio;

void main()
{
ubyte a = 15;
ubyte b = 10;

	ubyte c = a + b; //What is happening there?! ARGH! Are you 
joking?!


}

Compilation output:
/d837/f382.d(9): Error: cannot implicitly convert expression 
(cast(int)a + cast(int)b) of type int to ubyte


I'm just crazy about it! How could it happen?!


I just should forget about all integer type except *int*, because 
it make my head just explode!!!

How to say to compiler that I want to inherit final template bethod of base interface into derived class

[Uranuz via Digitalmars-d-learn]

The question is in the header:
How to say to compiler that I want to inherit final template 
bethod of base interface into derived class?


I have the following example. I know that it is maybe 
overcomplicated but still I need this feature in my code.


import std.stdio;

interface IBase
{

template getStr(string fieldName)
{
final string getStr()
{
return George;
}
}


string getStr(string fieldName);
}


class Derived: IBase
{
override string getStr(string fieldName)
{
return Sam;
}

}


void main()
{
auto obj = new Derived;

writeln( obj.getStr!(aaa)() );

}

Compilation output:
/d907/f266.d(33): Error: obj.getStr isn't a template


When I have all of these methods having the same name compiler 
shadows template method from the base interface. So the question 
is how to inherit template method without reimplementing it in 
derived class?

Re: How to test templates for equality?

[Uranuz via Digitalmars-d-learn]

template isMyInstanceOf(alias Templ, alias Inst)
{
alias Args = ???; //I don't have idea how to get it

enum bool isMyInstanceOf = __traits(isSame, Templ!(Args), 
Inst);

}

Do you have any idea how to solve this? May be standad library 
could be improved with such type of test for template instance?


Is new compiler trait is needed for solving this like
alias Args = __traits(getTemplateArgumentList, Inst);

or it could be solved with existing tools?

Re: How to test templates for equality?

[Uranuz via Digitalmars-d-learn]

I have another question about testing if given symbol is instance 
of the given template and geting it's template arguments. I'm 
talking about raw template symbols, but not struct or class 
templates. For case with struct or class template 
std.traits.isInstanceOf is working well. But using *raw* template 
is not possible for it. There is an example.


import std.stdio, std.traits;


template WrapperTemplate(T)
{}

void main()
{
writeln( isInstanceOf!(WrapperTemplate, WrapperTemplate!(int)) );
}

Because isInstanceOf implemented as *is* expression it expects 
type arguments, but template is not type at all. So this is not 
working. As we have __traits(isSame, ...) we could make such a 
test, but I need to have tuple of template arguments. But I don't 
understand how to get them


template isMyInstanceOf(alias Templ, alias Inst)
{

}

Re: How to test templates for equality?

[Uranuz via Digitalmars-d-learn]

Suddenly posted. I don't know why it's happened))

template isMyInstanceOf(alias Templ, alias Inst)
{
alias Args = ???; //I don't have idea how to get it

enum bool isMyInstanceOf = __traits(isSame, Templ!(Args), 
Inst);

}

Do you have any idea how to solve this? May be standad library 
could be improved with such type of test for template instance?

Re: How to test templates for equality?

[Uranuz via Digitalmars-d-learn]

On Tuesday, 1 July 2014 at 05:51:17 UTC, Peter Alexander wrote:

template Foo(T...) {}
template Bar(T...) {}

template isFoo(alias F)
{
enum isFoo = __traits(isSame, F, Foo);
}

pragma(msg, isFoo!Foo); // true
pragma(msg, isFoo!Bar); // false


Thanks for quick response. I really forget to look into language 
__traits statement.

How to test templates for equality?

[Uranuz via Digitalmars-d-learn]

I have a question. How could I know if some alias or template 
parameter is some template symbol. I want to not that I want to 
know that symbol is template symbol itself but not instance of 
template (std.traits.isInstanceOf give answer for that question). 
I'll give some example



template Foo(T...)
{

}

template isFoo(alias F)
{


}

Re: How to test templates for equality?

[Uranuz via Digitalmars-d-learn]

I suddenly posted it for somehow. But I hope idea is clear. How 
could I test if symbol is equal to some concrete template. I 
tried these examples:


template isFoo(alias F)
{
enum bool isFoo = is( F == Foo );
}

template isFoo(alias F)
{
enum bool isFoo = F == Foo;
}

Could you advise something to solve this?

Conflict between function and template with the same name

[Uranuz via Digitalmars-d-learn]

I have a question about this example code;

import std.stdio;

string getByName(string name)
{
return smth;
}

template getByName(string name)
{
enum
//string
getByName = getByName(name);
}


void main()
{
writeln(getByName!(name));
}

This produces compilation output:
/d967/f983.d(13): Error: forward reference of variable getByName
/d967/f983.d(19): Error: template instance f983.getByName!name 
error instantiating


Uncommenting line *//string* changes message to:

Compilation output:
/d976/f558.d(13): Error: recursive evaluation of getByName(name)
/d976/f558.d(19): Error: template instance f558.getByName!name 
error instantiating


Is there any reason why function and template conflict. They 
using different syntax to *call*. For template we have *!* but 
for function we don't have it. So why compiler is not able to see 
the difference?

Re: Conflict between function and template with the same name

[Uranuz via Digitalmars-d-learn]

import std.stdio;

string getByName(string name)
{
return smth;
}

template getByName(string name)
{
enum getByName = .getByName(name);
}


void main()
{
writeln(getByName!(name));
}


Thanks a lot! Very interesting. Do you see any reasoning why this 
happens?

Enum type deduction inside templates is not working

[Uranuz via Digitalmars-d-learn]

Compiler can't deduce type for template struct Pair when using it 
with enum argument.  There is an example


import std.stdio;

enum Category { first, second, third };

struct Pair(F, S)
{
F first;
S second;

this(F f, S s)
{
first = f;
second = s;
}
}


void main()
{
auto p = Pair(Category.first, first); //It fails

writeln(p);
}

Is it not working for some reason or I'm doing something wrong or 
is it just lack of implementation? How I could make this working 
without explicit specifying of types?

Re: Enum type deduction inside templates is not working

[Uranuz via Digitalmars-d-learn]

On Friday, 27 June 2014 at 06:14:48 UTC, pgtkda wrote:

On Friday, 27 June 2014 at 06:12:57 UTC, pgtkda wrote:
How I could make this

working without explicit specifying of types?


sorry, i should read better


Ok. Maybe it was discussed already somewhere, but I am not god in 
searching in English. Is there any directions about it? How could 
I work around it? Should I mail some proposal or bug report for 
it?

Re: Enum type deduction inside templates is not working

[Uranuz via Digitalmars-d-learn]

I think, D is a typesafe language, therefore you can't use 
variables with no type declaration.


One thing you can search for, are templates but even there you 
have to define a type:


import std.stdio;

enum Category : string { first = first}

template Pair(T)
{
T t;
T cat;
}


void main()
{
alias Pair!(string) a;
a.cat = Category.first;
a.t = first;

writeln(a.cat,  . , a.t);
}


Ok. I know that D is typesafe language, but I'm not going to do 
some implicit type casts in there, because type of Category.first 
is Category itself but not string or something. In this example 
`a.cat = Category.first;` tries to make implicit cast (I don't 
remember is it allowed or not)

Re: Enum type deduction inside templates is not working

[Uranuz via Digitalmars-d-learn]

Seems that I found answer myself. As far as I understand type 
inference is working only for template functions but not struct 
or class templates. This is why this not working and enum is not 
responsible for that.


I don't know why I use D enough long but I did not remember this 
fact.

Re: Enum type deduction inside templates is not working

[Uranuz via Digitalmars-d-learn]

There is proposal exists for this topic
http://wiki.dlang.org/DIP40

Re: Using attributes inside template instantiation

[Uranuz via Digitalmars-d-learn]

But if I write

@(hello) struct Hello {}

so all of the variables that have type Hello will have attribute 
@(hello) like come type qualifier because attribute is a part 
of declaration of Hello. Do I understand correctly?

Using attributes inside template instantiation

[Uranuz via Digitalmars-d-learn]

I'm trying to declare format for database record in compile time. 
I consider to use attributes fo this. Can I do something similar 
to this code?


struct RecordFormat(T)
{}

alias Format = RecordFormat!( @(cool) int );

pragma( msg, Format );

void main()
{
}

Or I want something strange that is not supported by language? 
For now I don't understand whether UDA are a part of types or 
they are a part of variable instance definition or something 
different (3rd dimension)).


For example 'const int' is a type but what @attribute int is? Can 
it be considered as separate type or it could be binded to 
definition of variable only?

@attribute int number;

I failed to alias type
alias coolInt = @(cool) int;

But I can alias const int
alias constInt = const int;

I think I understood something wrong about attributes.

Question about iteger literals

[Uranuz via Digitalmars-d-learn]

I have the following programme

import std.stdio;

bool isDigit(char c) nothrow
{
return c = '0'  c = '9';
}

ushort hexValue(char c) nothrow
{
if( isDigit(c) )
return c - '0';
else if (c = 'a'  c = 'f')
return c - 'a' + 10;
else if (c = 'A'  c = 'F')
return c - 'A' + 10;
else
return ushort.max;
}


void main()
{
writeln(hexValue('A')); 
}

This example is compiling successfully in DMD 2.064 but in DMD 
2.065 a got the following error:


/d544/f547.d(12): Error: cannot implicitly convert expression 
(cast(int)c - 48) of type int to ushort
/d544/f547.d(14): Error: cannot implicitly convert expression 
(cast(int)c - 97 + 10) of type int to ushort
/d544/f547.d(16): Error: cannot implicitly convert expression 
(cast(int)c - 65 + 10) of type int to ushort


So I have a question why these expressions are casted to int? I 
was thinking that result should be of char type. And it could be 
implicitly converted to ushort (because there is enough place to 
store result). Is it a bug in compiler or I should insert 
explicit casts?

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

ushort hexValue(in char c) pure nothrow @safe @nogc



else
return ushort.max;




I understand what pure, nothrow and @safe mean there. But what 
@nogc changes in there so I should use this modifier? Is it 
logical specifier that this function can be used without garbage 
collector or what?

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

In expression
 return c - 'a' + 10;
I could think that 10 has type int and resulting value promoted 
to the largest type. But I don't understand why in expression 
where both of arguments have type char:

return c - '0';
I have resulting type int. It's very strange for me and looks 
very buggy)

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

In D operations among chars return a int. The same happens in 
C/C++.


If you subtract a char from a char in general you can have a 
negative result, that can't fit in a char. So what's buggy is 
your thinking.


Ok. Thank you! I never thought about it that way

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

Another stupid question. Using this logic substraction for two 
uint values should return int too, because it can produce 
negative result. Am I right or not?

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

On Sunday, 22 June 2014 at 11:57:48 UTC, Uranuz wrote:
Another stupid question. Using this logic substraction for two 
uint values should return int too, because it can produce 
negative result. Am I right or not?


Now this code

import std.stdio;

void main()
{
uint a = 50;
uint b = 60;
auto c = a - b;

writeln(typeid(c));
}
produce output uint. It's some breakage in my logic. I am 
thinking that all integer-like types should behave similar way. I 
perceive char type as ubyte, that should be printed as symbol 
when using functions like writeln(). But the folowing example


import std.stdio;

void main()
{
ubyte a = 50;
ubyte b = 60;
auto c = a - b;

writeln(typeid(c));
}

produces output int like you said. Why there are so complicated 
rules in the *new* language. It's hard to understand the logic.

Re: Question about iteger literals

[Uranuz via Digitalmars-d-learn]

If these rules are not so clear and have some exceptions (but I 
don't understand why they are needed) then some documentation 
needed about this. But I would prefer to have result of uint 
substraction like uint, and char substraction like char. If we 
will changing all the types it will be kind of mess. Using this 
logic we should have some bigger type for int multiplication 
operator to fit in result of multiplication of int.max*int.max. I 
know that some assembler operations do this and multiplication of 
two registers with byte size results in placing product into two 
result register. But in context of higher level programming 
language it's better to have better type consistensy. Or we will 
nead a bigger type to store product for ulong.max*ulong.max 
result. Is it good or not?

Re: Dub. Mercurial (bitbucket.org). Projects deployment

[Uranuz via Digitalmars-d-learn]

Thanks for all the answers)

8. I have another more simple question about rdmd utility. It 
takes one *.d file and searches for all dependencies. What if I 
need to pass independent *.d file or *.ddoc file directly to dmd 
compiler? How could I do that using dmd? I have no idea how I 
could include *.ddoc file with set of DDOC macroses. I have tried 
to use string mixin.


mixin(import(mysettings.ddoc));

But I haven't succeed. My be compiler strips all the comments 
before mixing in or I doing something wrong. Another way is to 
use dmd.conf but I don't like this, because it's brutal way of 
doing so and as I think it's not compiler independent.

Dub. Mercurial (bitbucket.org). Projects deployment

[Uranuz via Digitalmars-d-learn]

I have web-application project in D language hosted on 
bitbucket.org. So I using Mercurial repository. I exactly have 
two *logical* projects but currently they are in one repo. The 
first is my library that includes not only D code, but also some 
resources like HTML-page templates (not compiled vibe's diet 
templates), CSS and also some JavaScript code. The second project 
is website itself. It also has D sources, images, CSS's, js's, 
etc.


1. My goal is to separate this REPO into two: library and website 
that depends on library. Bitbucket has option for having several 
private repos for user, that are visible only to users from the 
list of invited users. I want to publish the library under some 
free license. But I don't want to publish web-site repository. 
It's offtopic question, but can you give some advice how I could 
handle this? May be someone read some pages in bitbucket doc and 
has link :)


2. For some time I used rdmd and some small shell script for 
building my web-site. And also I haven't built any ddoc coments 
but I faced with it's necessity now. rdmd takes only one input 
file and then search for all import directives recursively to 
find all other files to compile. Problem is that I want to pass 
some *.ddoc file with some DDOC macro to dmd but I don't' whether 
it's possible, because I can pass only 1 file to rdmd. How it 
could be solved?


3. Then I was thinking about using dub as long as it can 
automatically manage dependencies and it's higher level tool. And 
I can maybe pass *.ddoc file with general macro with 
*sourceFiles* (I'm not sure about this). But I think that dub 
doesn't support Mercurial and working with private repos. I can 
download project manually from Bitbucket. But it would be good to 
automate this. Not all programmers working with github and even 
git)) May be it should be solved somehow. I could participate in 
it but haven't contributed anything to D yet((. And also I don't 
know Mercurial and Bitbucket's API.


4. Another question about dub is how project structure looks like 
when I use some subprojects or libraries in my project. Examples 
in dub repository are very very simple and don't show advantages 
of dub over plain using of dmd or rdmd. So for now I don't 
understand the idea of this tool. Maybe some examples of *big and 
complicated* project would help. It would be better if it uses 
different sources for dependencies. I would like to see source 
from bitbucket.org, github.org, using binary libraries, local 
sources - all in one dub project)) This will show that this 
system is useful and tasty))


5. Also I would like to use dub for deployment some small 
projects: copy come files, create some folder structure, make 
some symbolic links, run *.css, *.js processing and minification 
tools, run some service daemon apps, etc. May be it can be 
handled with *preBuildCommands*, *postBuildCommands* directives 
for now and using some shell scripts or running deployment 
application on D))


P.S. It would be a plesure to see answers for all the items if 
possible, not only discussion around))

Re: Dub. Mercurial (bitbucket.org). Projects deployment

[Uranuz via Digitalmars-d-learn]

Also I have additional question to this post.
6. If I would convert my repo to git, but use anather hosting 
that github.org for example my own local server or bitbucket.org. 
How could I specify source for loading dependencies? This is 
unclear from dub documentation. Is it a tool for working with 
concrete web-repository?


7. Also I have a question about structure of folders that dub 
creates. I tried to implement example from vibed.org and created 
test web-server using dub. As I see dub is loading dependencies 
into ~/.dub (on Linux). In my application I have some resources 
that used by application at runtime. These are static data like 
*.html, *.css, images, *.js and other files that included in 
library tha I want to use in my application. What is a good 
approach? Create a separate working folder where I will copy all 
resource files or create symbolic links to folders or write paths 
to this library inside ~/.dup. This is all about general 
organization of project that is not considered very well in 
articles. And I don't know how it can be solved for projects on D 
language.